id
stringlengths 9
16
| abstract
stringlengths 67
2.61k
| cats
sequence | primary
stringlengths 5
18
| secondary
stringlengths 0
18
| strlabel
stringlengths 5
315
| stratlabel
class label 7.27k
classes |
|---|---|---|---|---|---|---|
2307.12179 | We investigate the problem of Object State Classification (OSC) as a
zero-shot learning problem. Specifically, we propose the first Object-agnostic
State Classification (OaSC) method that infers the state of a certain object
without relying on the knowledge or the estimation of the object class. In that
direction, we capitalize on Knowledge Graphs (KGs) for structuring and
organizing knowledge, which, in combination with visual information, enable the
inference of the states of objects in object/state pairs that have not been
encountered in the method's training set. A series of experiments investigate
the performance of the proposed method in various settings, against several
hypotheses and in comparison with state of the art approaches for object
attribute classification. The experimental results demonstrate that the
knowledge of an object class is not decisive for the prediction of its state.
Moreover, the proposed OaSC method outperforms existing methods in all datasets
and benchmarks by a great margin.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
1102.3201 | In this paper, we focus on two classes of D-invariant polynomial subspaces.
The first is a classical type, while the second is a new class. With matrix
computation, we prove that every ideal projector with each D-invariant subspace
belonging to either the first class or the second is the pointwise limit of
Lagrange projectors. This verifies a particular case of a C. de Boor's
conjecture asserting that every complex ideal projector is the pointwise limit
of Lagrange projectors. Specifically, we provide the concrete perturbation
procedure for ideal projectors of this type.
| [
"math.NA"
] | math.NA | Numerical Analysis | 5,002Numerical Analysis
|
|
2310.13041 | We extend the covariant color-kinematics duality introduced by Cheung and
Mangan to effective field theories. We focus in particular on relations between
the effective field theories of gluons only and of gluons coupled to bi-adjoint
scalars. Maps are established between their respective equations of motion and
between their tree-level scattering amplitudes. An additional rule for the
replacement of flavor structures by kinematic factors realizes the map between
higher-derivative amplitudes. As an example of new relations, the pure-gluon
amplitudes of mass dimension up to eight, featuring insertions of the $F^3$ and
$F^4$ operators which satisfy the traditional color-kinematics duality, can be
generated at all multiplicities from just renormalizable amplitudes of gluons
and bi-adjoint scalars. We also obtain closed-form expressions for the
kinematic numerators of the dimension-six gluon effective field theory, which
are valid in $D$ space-time dimensions. Finally, we find strong evidence that
this extended covariant color-kinematics duality relates the
$(DF)^2+$YM$(+\phi^3)$ theories which, at low energies, generate infinite
towers of operators satisfying the traditional color-kinematics duality, beyond
aforementioned $F^3$ and $F^4$ ones.
| [
"hep-th",
"hep-ph"
] | hep-th | hep-ph | High Energy Physics - Theory;High Energy Physics - Phenomenology | 3,348High Energy Physics - Theory;High Energy Physics - Phenomenology
|
2105.11477 | Atomic-level imperfections play an increasingly critical role in nanophotonic
device performance. However, it remains challenging to accurately characterize
the sidewall roughness with sub-nanometer resolution and directly correlate
this roughness with device performance. We have developed a method that allows
us to measure the sidewall roughness of waveguides made of any material
(including dielectrics) using the high resolution of atomic force microscopy.
We illustrate this method by measuring state-of-the-art photonic devices made
of silicon nitride. We compare the roughness of devices fabricated using both
DUV photo-lithography and electron-beam lithography for two different etch
processes. To correlate roughness with device performance we describe what we
call a new Payne-Lacey Bending model, which adds a correction factor to the
widely used Payne-Lacey model so that losses in resonators and waveguides with
bends can be accurately predicted given the sidewall roughness, waveguide width
and bending radii. Having a better way to measure roughness and use it to
predict device performance can allow researchers and engineers to optimize
fabrication for state-of-the-art photonics using many materials.
| [
"physics.optics",
"physics.app-ph"
] | physics.optics | physics.app-ph | Optics;Applied Physics | 5,150Optics;Applied Physics
|
quant-ph/0507227 | We investigate the maximal violation of Bell inequalities for two
$d$-dimensional systems by using the method of Bell operator. The maximal
violation corresponds to the maximal eigenvalue of the Bell operator matrix.
The eigenvectors corresponding to these eigenvalues are described by asymmetric
entangled states. We estimate the maximum value of the eigenvalue for large
dimension. A family of elegant entangled states $|\Psi>_{\rm app}$ that violate
Bell inequality more strongly than the maximally entangled state but are
somewhat close to these eigenvectors is presented. These approximate states can
potentially be useful for quantum cryptography as well as many other important
fields of quantum information.
| [
"quant-ph"
] | quant-ph | Quantum Physics | 5,985Quantum Physics
|
|
1211.2911 | We report the analysis of the rotational properties of our sample of Herbig
Ae/Be (HAeBe) and related stars for which we have obtained high-resolution
spectropolarimetric observations. Using the projected rotational velocities
measured at the surface of the stars, we have calculated the angular momentum
of the sample and plotted it as a function of age. We have then compared the
angular momentum and the vsini distributions of the magnetic to the
non-magnetic HAeBe stars. Finally we have predicted the vsini of the
non-magnetic, non-binary ("normal") stars in our sample when they reach the
ZAMS, and compared them to various catalogues of the vsini of main-sequence
stars. First, we observe that magnetic HAeBe stars are much slower rotators
than normal stars, indicating that they have been more efficiently braked than
the normal stars. In fact, the magnetic stars have already lost most of their
angular momentum, despite their young ages (lower than 1 Myr for some of them).
Secondly, our analysis suggests that the low mass (1.5 < M < 5 Msun) normal
HAeBe stars evolve with constant angular momentum towards the ZAMS, while the
high-mass normal HAeBe stars (M > 5 Msun) are losing angular momentum. We
propose that winds, which are expected to be stronger in massive stars, are at
the origin of this phenomenon.
| [
"astro-ph.SR"
] | astro-ph.SR | Solar and Stellar Astrophysics | 6,668Solar and Stellar Astrophysics
|
|
math/0510525 | In this note we give upper bounds for the free energy of discrete polymers in
random media. The bounds are given by the so-called generalized multiplicative
cascades from the statistical theory of turbulence. For the polymer model, we
derive that the quenched free energy is different from the annealed one in
dimension 1, for any finite temperature and general environment. This implies
localization of the polymer.
| [
"math.PR"
] | math.PR | Probability | 5,709Probability
|
|
1706.07078 | This paper formulates two 3D stochastic differential equations (SDEs) of two
microbial populations in a chemostat competing over a single substrate. The two
models have two distinct noise sources. One is general noise whereas the other
is dilution rate induced noise. Nonlinear Monod growth rates are assumed and
the paper is mainly focused on the parameter values where coexistence is
present deterministically. Nondimensionalising the equations around the point
of intersection of the two growth rates leads to a large parameter which is the
nondimensional substrate feed. This in turn is used to perform an asymptotic
analysis leading to a reduced 2D system of equations describing the dynamics of
the populations on and close to a line of steady states retrieved from the
deterministic stability analysis. That reduced system allows the formulation of
a spatially 2D Fokker-Planck equation which when solved numerically admits
results similar to those from simulation of the SDEs. Contrary to previous
suggestions, one particular population becomes dominant at large times.
Finally, we brie y explore the case where death rates are added.
| [
"math.DS",
"q-bio.PE"
] | math.DS | q-bio.PE | Dynamical Systems;Populations and Evolution | 2,336Dynamical Systems;Populations and Evolution
|
2003.11407 | This paper presents one of the case studies of the Gamma Factory initiative
-- a proposal of a new operation scheme of ion beams in the CERN accelerator
complex. Its goal is to extend the scope and precision of the LHC-based
research by complementing the proton-proton collision programme with the
high-luminosity nucleus-nucleus one. Its numerous physics highlights include
studies of the exclusive Higgs-boson production in photon-photon collisions and
precision measurements of the electroweak (EW) parameters. There are two
principal ways to increase the LHC luminosity which do not require an upgrade
of the CERN injectors: (1) modification of the beam-collision optics and (2)
reduction of the transverse emittance of the colliding beams. The former scheme
is employed by the ongoing high-luminosity (HL-LHC) project. The latter one,
applicable only to ion beams, is proposed in this paper. It is based on laser
cooling of bunches of partially stripped ions at the SPS flat-top energy. For
isoscalar calcium beams, which fulfil the present beam-operation constrains and
which are particularly attractive for the EW physics, the transverse beam
emittance can be reduced by a factor of $5$ within the $8$ seconds long cooling
phase. The predicted nucleon-nucleon luminosity of $L_{NN}= 4.2 \times
10^{34}\,$s$^{-1}$cm$^{-2}$ for collisions of the cooled calcium beams at the
LHC top energy is comparable to the levelled luminosity for the HL-LHC
proton-proton collisions, but with reduced pile-up background. The scheme
proposed in this paper, if confirmed by the future Gamma Factory
proof-of-principle experiment, could be implemented at CERN with minor
infrastructure investments.
| [
"physics.acc-ph",
"hep-ex",
"physics.atom-ph"
] | physics.acc-ph | hep-ex | Accelerator Physics;High Energy Physics - Experiment;Atomic Physics | 7,267longtail
|
1507.00841 | We evaluate the Onsager matrix for a system under time-periodic driving by
considering all its Fourier components. By application of the second law, we
prove that all the fluxes converge to zero in the limit of zero dissipation.
Reversible efficiency can never be reached at finite power. The implication for
an Onsager matrix, describing reduced fluxes, is that its determinant has to
vanish. In the particular case of only two fluxes, the corresponding Onsager
matrix becomes symmetric.
| [
"cond-mat.stat-mech"
] | cond-mat.stat-mech | Statistical Mechanics | 6,821Statistical Mechanics
|
|
1907.13015 | The diffraction of electromagnetic waves at the surface periodic structures
accompanied by strong anomalous effects in different diffraction orders is
considered in great detail for high-contrast interfaces. We restrict our
discussion to the TM polarization of the incident wave (the magnetic field is
orthogonal to the plane of incidence) and the simplest geometry when the plane
of incidence is orthogonal to the grating grooves. The most attention is
focused on the strong maxima and minima of the energy flux density accompanying
specific grazing propagation of some diffraction order. Relation to other
anomalies, both Rayleigh and the resonance ones is discussed as well.
| [
"physics.optics",
"cond-mat.other"
] | physics.optics | cond-mat.other | Optics;Other Condensed Matter | 5,214Optics;Other Condensed Matter
|
2307.13807 | This paper presents a novel approach for optimizing betting strategies in
sports gambling by integrating Von Neumann-Morgenstern Expected Utility Theory,
deep learning techniques, and advanced formulations of the Kelly Criterion. By
combining neural network models with portfolio optimization, our method
achieved remarkable profits of 135.8% relative to the initial wealth during the
latter half of the 20/21 season of the English Premier League. We explore
complete and restricted strategies, evaluating their performance, risk
management, and diversification. A deep neural network model is developed to
forecast match outcomes, addressing challenges such as limited variables. Our
research provides valuable insights and practical applications in the field of
sports betting and predictive modeling.
| [
"q-fin.PM",
"cs.LG"
] | q-fin.PM | cs.LG | Portfolio Management;Machine Learning | 5,687Portfolio Management;Machine Learning
|
0810.0121 | We model tri-bimaximal lepton mixing from first principles in a way that
avoids the problem of the vacuum alignment characteristic of such models. This
is achieved by using a softly broken A4 symmetry realized with an isotriplet
fermion, also triplet under A4. No scalar A4-triplet is introduced. This
represents one possible realization of general schemes characterized by the
minimal set of either three or five physical parameters. In the three parameter
versions mee vanishes, while in the five parameter schemes the absolute scale
of neutrino mass, although not predicted, is related to the two Majorana
phases. The model realization we discuss is potentially testable at the LHC
through the peculiar leptonic decay patterns of the fermionic and scalar
triplets.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
1403.4825 | We report and classify the rich variety of patterns forming spontaneously in
the oxide layer during the oscillatory photoelectrodissolution of n-type doped
silicon electrodes under limited illumination. Remarkably, these patterns are
often comprised of several dynamical states coexisting on the electrode, such
as subharmonic phase clusters and spatio-temporal chaos, and include so-called
'chimera states'. The experiments suggest that the subharmonic phase clusters
emerge from a period doubling bifurcation which, upon further parameter
changes, evolve into classical phase clusters. Experimentally the occurrence of
the patterns is controlled via two coupling mechanisms: A linear global
coupling by an external resistor and a nonlinear coupling imposed on the system
by the limitation of the illumination.
| [
"nlin.PS",
"cond-mat.dis-nn",
"nlin.CD"
] | nlin.PS | cond-mat.dis-nn | Pattern Formation and Solitons;Disordered Systems and Neural Networks;Chaotic Dynamics | 7,267longtail
|
2311.11981 | With the rapid advancement of machine learning models for NLP tasks,
collecting high-fidelity labels from AI models is a realistic possibility.
Firms now make AI available to customers via predictions as a service (PaaS).
This includes PaaS products for healthcare. It is unclear whether these labels
can be used for training a local model without expensive annotation checking by
in-house experts. In this work, we propose a new framework for Human Correction
of AI-Generated Labels (H-COAL). By ranking AI-generated outputs, one can
selectively correct labels and approach gold standard performance (100% human
labeling) with significantly less human effort. We show that correcting 5% of
labels can close the AI-human performance gap by up to 64% relative
improvement, and correcting 20% of labels can close the performance gap by up
to 86% relative improvement.
| [
"cs.CL"
] | cs.CL | Computation and Language | 1,168Computation and Language
|
|
2008.03453 | LTE based Cellular Vehicle-To-Everything (C-V2X) allows vehicles to
communicate with each other directly without the need for infrastructure and is
expected to be a critical enabler for connected and autonomous vehicles. V2X
communication based safety applications are built on periodic broadcast of
basic safety messages with vehicle state information. Vehicles use this
information to identify collision threats and take appropriate countermeasures.
As the vehicle density increases, these broadcasts can congest the
communication channel resulting in increased packet loss; fundamentally
impacting the ability to identify threats in a timely manner. To address this
issue, it is important to incorporate a congestion control mechanism.
Congestion management scheme based on rate and power control has proved to be
effective for DSRC. In this paper, we investigate the suitability of similar
congestion control to C-V2X with particular focus on transmit power control. In
our evaluation, we include periodic basic safety messages and high priority
event messages that are generated when an event such as hard braking occurs.
Our study reveals that while power control does not improve packet delivery
performance of basic safety messages, it is beneficial to high priority event
message delivery. In this paper, we investigate the reasons for this behavior
using simulations and analysis.
| [
"cs.NI"
] | cs.NI | Networking and Internet Architecture | 4,711Networking and Internet Architecture
|
|
1404.3878 | Non-intrusive load monitoring, or energy disaggregation, aims to separate
household energy consumption data collected from a single point of measurement
into appliance-level consumption data. In recent years, the field has rapidly
expanded due to increased interest as national deployments of smart meters have
begun in many countries. However, empirically comparing disaggregation
algorithms is currently virtually impossible. This is due to the different data
sets used, the lack of reference implementations of these algorithms and the
variety of accuracy metrics employed. To address this challenge, we present the
Non-intrusive Load Monitoring Toolkit (NILMTK); an open source toolkit designed
specifically to enable the comparison of energy disaggregation algorithms in a
reproducible manner. This work is the first research to compare multiple
disaggregation approaches across multiple publicly available data sets. Our
toolkit includes parsers for a range of existing data sets, a collection of
preprocessing algorithms, a set of statistics for describing data sets, two
reference benchmark disaggregation algorithms and a suite of accuracy metrics.
We demonstrate the range of reproducible analyses which are made possible by
our toolkit, including the analysis of six publicly available data sets and the
evaluation of both benchmark disaggregation algorithms across such data sets.
| [
"stat.AP"
] | stat.AP | Applications | 276Applications
|
|
1406.5559 | Two different approaches to gravitational perturbation theory appear to give
two different answers for the properties of gravitational wave memory. We show
that this contradiction is only apparent and the two approaches actually agree.
| [
"gr-qc"
] | gr-qc | General Relativity and Quantum Cosmology | 2,674General Relativity and Quantum Cosmology
|
|
0707.1365 | Let $I$ be a homogeneous Artinian ideal in a polynomial ring
$R=k[x_1,...,x_n]$ over a field $k$ of characteristic 0. We study an equivalent
condition for the generic initial ideal $\gin(I)$ with respect to reverse
lexicographic order to be almost reverse lexicographic. As a result, we show
that Moreno-Socias conjecture implies Fr\"{o}berg conjecture. And for the case
$\Codim I \le 3$, we show that $R/I$ has the strong Lefschetz property if and
only if $\gin(I)$ is almost reverse lexicographic. Finally for a monomial
complete intersection Artinian ideal $I=(x_1^{d_1},...,x_n^{d_n})$, we prove
that $\gin(I)$ is almost reverse lexicographic if $d_i > \sum_{j=1}^{i-1} d_j -
i + 1$ for each $i \ge 4$. Using this, we give a positive partial answer to
Moreno-Socias conjecture, and to Fr\"{o}berg conjecture.
| [
"math.AC"
] | math.AC | Commutative Algebra | 1,107Commutative Algebra
|
|
cond-mat/0605135 | A method is presented for first-principles calculations of inelastic mean
free paths and stopping powers in condensed matter over a broad energy range.
The method is based on {\it ab initio} calculations of the dielectric function
in the long wavelength limit using a real-space Green's function formalism,
together with extensions to finite momentum transfer. From these results we
obtain the loss function and related quantities such as optical-oscillator
strengths and mean excitation energies. From a many-pole representation of the
dielectric function we then obtain the electron self-energy and inelastic mean
free paths (IMFP). Finally using our calculated dielectric function and the
optical-data model of Fern\'andez-Varea {\it et al}., we obtain collision
stopping powers (CSP) and penetration ranges. The results are consistent with
semi-empirical approaches and with experiment.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
2012.01696 | Training a fair machine learning model is essential to prevent demographic
disparity. Existing techniques for improving model fairness require broad
changes in either data preprocessing or model training, rendering themselves
difficult-to-adopt for potentially already complex machine learning systems. We
address this problem via the lens of bilevel optimization. While keeping the
standard training algorithm as an inner optimizer, we incorporate an outer
optimizer so as to equip the inner problem with an additional functionality:
Adaptively selecting minibatch sizes for the purpose of improving model
fairness. Our batch selection algorithm, which we call FairBatch, implements
this optimization and supports prominent fairness measures: equal opportunity,
equalized odds, and demographic parity. FairBatch comes with a significant
implementation benefit -- it does not require any modification to data
preprocessing or model training. For instance, a single-line change of PyTorch
code for replacing batch selection part of model training suffices to employ
FairBatch. Our experiments conducted both on synthetic and benchmark real data
demonstrate that FairBatch can provide such functionalities while achieving
comparable (or even greater) performances against the state of the arts.
Furthermore, FairBatch can readily improve fairness of any pre-trained model
simply via fine-tuning. It is also compatible with existing batch selection
techniques intended for different purposes, such as faster convergence, thus
gracefully achieving multiple purposes.
| [
"cs.LG",
"cs.AI",
"stat.ML"
] | cs.LG | cs.AI | Machine Learning;Artificial Intelligence;Machine Learning | 3,951Machine Learning;Artificial Intelligence;Machine Learning
|
2201.03350 | Shafarevich conjecture/problem is about the finiteness of isomorphism classes
of a family of varieties defined over a number field with good reduction
outside a finite collection of places. For K3 surfaces, such a finiteness
result was proved by Y. She. For hyper-K\"ahler varieties, which are
higher-dimensional analogs of K3 surfaces, Y. Andr\'e has verified the
Shafarevich conjecture for hyper-K\"ahler varieties of a given dimension and
admitting a very ample polarization of bounded degree. In this paper, we
provide a unification of both results by proving the (unpolarized) Shafarevich
conjecture for hyper-K\"ahler varieties in a given deformation type. In a
similar fashion, generalizing a result of Orr and Skorobogatov on K3 surfaces,
we prove the finiteness of geometric isomorphism classes of hyper-K\"ahler
varieties of CM type in a given deformation type defined over a number field
with bounded degree. A key to our approach is a uniform Kuga--Satake map,
inspired by She's work, and we study its arithmetic properties, which are of
independent interest.
| [
"math.AG",
"math.NT"
] | math.AG | math.NT | Algebraic Geometry;Number Theory | 137Algebraic Geometry;Number Theory
|
1809.07007 | We consider a new class of potentially exotic group C*-algebras
$C^*_{PF_p^*}(G)$ for a locally compact group $G$, and its connection with the
class of potentially exotic group C*-algebras $C^*_{L^p}(G)$ introduced by
Brown and Guentner. Surprisingly, these two classes of C*-algebras are
intimately related. By exploiting this connection, we show
$C^*_{L^p}(G)=C^*_{PF_p^*}(G)$ for $p\in (2,\infty)$, and the C*-algebras
$C^*_{L^p}(G)$ are pairwise distinct for $p\in (2,\infty)$ when $G$ belongs to
a large class of nonamenable groups possessing the Haagerup property and either
the rapid decay property or Kunze-Stein phenomenon by characterizing the
positive definite functions that extend to positive linear functionals of
$C^*_{L^p}(G)$ and $C^*_{PF_p^*}(G)$. This greatly generalizes earlier results
of Okayasu and the second author on the pairwise distinctness of $C^*_{L^p}(G)$
for $2<p<\infty$ when $G$ is either a noncommutative free group or the group
$SL(2,\mathbb R)$, respectively.
As a byproduct of our techniques, we present two applications to the theory
of unitary representations of a locally compact group $G$. Firstly, we give a
short proof of the well-known Cowling-Haagerup-Howe Theorem which presents
sufficient condition implying the weak containment of a cyclic unitary
representation of $G$ in the left regular representation of $G$. Also we give a
near solution to a 1978 conjecture of Cowling. This conjecture of Cowling
states if $G$ is a Kunze-Stein group and $\pi$ is a unitary representation of
$G$ with cyclic vector $\xi$ such that the map $$G\ni s\mapsto \langle
\pi(s)\xi,\xi\rangle$$ belongs to $L^p(G)$ for some $2< p <\infty$, then
$A_\pi\subseteq L^p(G)$. We show $B_\pi\subseteq L^{p+\epsilon}(G)$ for every
$\epsilon>0$ (recall $A_\pi\subseteq B_\pi$).
| [
"math.OA",
"math.FA",
"math.GR",
"math.RT"
] | math.OA | math.FA | Operator Algebras;Functional Analysis;Group Theory;Representation Theory | 7,267longtail
|
0910.5665 | We present the stellar mass-size relations for elliptical, lenticular, and
spiral galaxies in the field and cluster environments using HST/ACS imaging and
data from the Space Telescope A901/2 Galaxy Evolution Survey (STAGES). We use a
large sample of ~1200 field and cluster galaxies, and a sub-sample of cluster
core galaxies, and quantify the significance of any putative environmental
dependence on the stellar mass-size relation. For elliptical, lenticular, and
high-mass (log M*/M_sun > 10) spiral galaxies we find no evidence to suggest
any such environmental dependence, implying that internal drivers are governing
their size evolution. For intermediate/low-mass spirals (log M*/M_sun < 10) we
find evidence, significant at the 2-sigma level, for a possible environmental
dependence on galaxy sizes: the mean effective radius a_e for lower-mass
spirals is ~15-20 per cent larger in the field than in the cluster. This is due
to a population of low-mass large-a_e field spirals that are largely absent
from the cluster environments. These large-a_e field spirals contain extended
stellar discs not present in their cluster counterparts. This suggests the
fragile extended stellar discs of these spiral galaxies may not survive the
environmental conditions in the cluster. Our results suggest that internal
physical processes are the main drivers governing the size evolution of
galaxies, with the environment possibly playing a role affecting only the discs
of intermediate/low-mass spirals.
| [
"astro-ph.CO"
] | astro-ph.CO | Cosmology and Nongalactic Astrophysics | 1,725Cosmology and Nongalactic Astrophysics
|
|
2209.08700 | In this article we propose formulas for the connected K-theory class of the
pointed Brill-Noether loci in Prym varieties, which extends the result by
Concini and Pragacz. Applying the formulas, we compute the holomorphic Euler
Characteristics of the loci.
| [
"math.AG",
"math.CO"
] | math.AG | math.CO | Algebraic Geometry;Combinatorics | 70Algebraic Geometry;Combinatorics
|
1412.6412 | We use a collection of Python programs for numerical simulation of liver
perfusion. We have an application for semi-automatic generation of a finite
element mesh of the human liver from computed tomography scans and for
reconstruction of the liver vascular structure. When the real vascular trees
can not be obtained from the CT data we generate artificial trees using the
constructive optimization method. The generated FE mesh and vascular trees are
imported into SfePy (Simple Finite Elements in Python) and numerical
simulations are performed in order to get the pressure distribution and
perfusion flows in the liver tissue. In the post-processing steps we calculate
transport of a contrast fluid through the liver parenchyma.
| [
"cs.CE"
] | cs.CE | Computational Engineering, Finance, and Science | 1,311Computational Engineering, Finance, and Science
|
|
1904.00697 | Motivated by recent progress in operator representation of frames, we
investigate the frames of the form $ \{T^n \varphi\}_{n\in I}$ for $
I=\mathbb{N}, \mathbb{Z} $, and answer questions about representations,
perturbations and frames induced by the action of powers of bounded linear
operators. As a particular case, we discuss problems concerning representation
of frames in terms of iterations of the mixed frame operators. As our another
contribution, we consider frames of the form $ \{a_n T^n
\varphi\}_{n=0}^{\infty} $ for some non-zero scalars $ \{a_n\}_{n=0}^{\infty}
$, and we obtain some new results in dynamical sampling. Finally, we will
present some auxiliary results related to the perturbation of sequences of the
form $ \{T^n \varphi\}_{n=0}^{\infty}$.
| [
"math.FA",
"math.OA"
] | math.FA | math.OA | Functional Analysis;Operator Algebras | 2,591Functional Analysis;Operator Algebras
|
2006.02922 | We explore the Atiyah-Hirzebruch spectral sequence for the
$tmf^\bullet[\frac12]$-cohomology of the classifying space $BM_{24}$ of the
largest Mathieu group $M_{24}$, twisted by a class $\omega \in
H^4(BM_{24};Z[\frac12]) \cong Z_3$. Our exploration includes detailed
computations of the $Z_3$-cohomology of $M_{24}$ and of the first few
differentials in the AHSS. We are specifically interested in the value of
$tmf^\bullet_\omega(BM_{24})[\frac12]$ in cohomological degree $-27$. Our main
computational result is that $tmf^{-27}_\omega(BM_{24})[\frac12] = 0$ when
$\omega \neq 0$. For comparison, the restriction map
$tmf^{-3}_\omega(BM_{24})[\frac12]\to tmf^{-3}(pt)[\frac12] \cong Z_3$ is
surjective for one of the two nonzero values of $\omega$.
Our motivation comes from Mathieu Moonshine. Assuming a well-studied
conjectural relationship between $TMF$ and supersymmetric quantum field theory,
there is a canonically-defined $Co_1$-twisted-equivariant lifting
$[\bar{V}^{f\natural}]$ of the class $\{24\Delta\} \in TMF^{-24}(pt)$, where
$Co_1$ denotes Conway's largest sporadic group. We conjecture that the product
$[\bar{V}^{f\natural}] \nu$, where $\nu \in TMF^{-3}(pt)$ is the image of the
generator of $tmf^{-3}(pt) \cong Z_{24}$, does not vanish $Co_1$-equivariantly,
but that its restriction to $M_{24}$-twisted-equivariant $TMF$ does vanish.
This conjecture answers some of the questions in Mathieu Moonshine: it implies
the existence of a minimally supersymmetric quantum field theory with $M_{24}$
symmetry, whose twisted-and-twined partition functions have the same mock
modularity as in Mathieu Moonshine. Our AHSS calculation establishes this
conjecture "perturbatively" at odd primes.
An appendix included mostly for entertainment purposes discusses
"$\ell$-complexes" and their relation to $\mathrm{SU}(2)$ Verlinde rings. The
case $\ell=3$ is used in our AHSS calculations.
| [
"math.AT",
"hep-th",
"math.GR",
"math.KT"
] | math.AT | hep-th | Algebraic Topology;High Energy Physics - Theory;Group Theory;K-Theory and Homology | 7,267longtail
|
1904.09535 | Deep Neural Networks (DNN) have been widely employed in industry to address
various Natural Language Processing (NLP) tasks. However, many engineers find
it a big overhead when they have to choose from multiple frameworks, compare
different types of models, and understand various optimization mechanisms. An
NLP toolkit for DNN models with both generality and flexibility can greatly
improve the productivity of engineers by saving their learning cost and guiding
them to find optimal solutions to their tasks. In this paper, we introduce
NeuronBlocks\footnote{Code: \url{https://github.com/Microsoft/NeuronBlocks}}
\footnote{Demo: \url{https://youtu.be/x6cOpVSZcdo}}, a toolkit encapsulating a
suite of neural network modules as building blocks to construct various DNN
models with complex architecture. This toolkit empowers engineers to build,
train, and test various NLP models through simple configuration of JSON files.
The experiments on several NLP datasets such as GLUE, WikiQA and CoNLL-2003
demonstrate the effectiveness of NeuronBlocks.
| [
"cs.CL"
] | cs.CL | Computation and Language | 1,168Computation and Language
|
|
1508.06867 | Coarse Structural Nested Mean Models (SNMMs) provide useful tools to estimate
treatment effects from longitudinal observational data with time-dependent
confounders. Coarse SNMMs lead to a large class of estimators,within which an
optimal estimator can be derived under the conditions of well-specified models
for the treatment effect, for treatment initiation, and for nuisance regression
outcomes (Lok & Griner, 2015). The key assumption lies in a well-specified
model for the treatment effect; however, there is no existing guidance to
specify the treatment effect model, and model misspecification leads to biased
estimators, preventing valid inference. To test whether the treatment effect
model matches the data well, we derive a goodness-of-fit (GOF) test procedure
based on overidentification restrictions tests (Sargan, 1958; Hansen, 1982). We
show that our GOF statistic is doubly-robust in the sense that with a correct
treatment effect model, if either the treatment initiation model or the
nuisance regression outcome model is correctly specified, the GOF statistic has
a Chi-squared limiting distribution with degrees of freedom equal to the number
of overidentification restrictions. We demonstrate the empirical relevance of
our methods using simulation designs based on an actual dataset. In addition,
we apply the GOF test procedure to study how the initiation time of highly
active antiretroviral treatment (HAART) after infection predicts the one-year
treatment effect in HIV-positive patients with acute and early infection.
| [
"stat.ME"
] | stat.ME | Methodology | 4,557Methodology
|
|
1410.2034 | In this note we sketch an initial tentative approach to funding costs
analysis and management for contracts with bilateral counterparty risk in a
simplified setting. We depart from the existing literature by analyzing the
issue of funding costs and benefits under the assumption that the associated
risks cannot be hedged properly. We also model the treasury funding spread by
means of a stochastic Weighted Cost of Funding Spread (WCFS) which helps
describing more realistic financing policies of a financial institution. We
elaborate on some limitations in replication-based Funding / Credit Valuation
Adjustments we worked on ourselves in the past, namely CVA, DVA, FVA and
related quantities as generally discussed in the industry. We advocate as a
different possibility, when replication is not possible, the analysis of the
funding profit and loss distribution and explain how long term funding spreads,
wrong way risk and systemic risk are generally overlooked in most of the
current literature on risk measurement of funding costs. As a matter of initial
illustration, we discuss in detail the funding management of interest rate
swaps with bilateral counterparty risk in the simplified setup of our framework
through numerical examples and via a few simplified assumptions.
| [
"q-fin.RM"
] | q-fin.RM | Risk Management | 6,311Risk Management
|
|
1708.07303 | This paper focuses on the problem of learning 6-DOF grasping with a parallel
jaw gripper in simulation. We propose the notion of a geometry-aware
representation in grasping based on the assumption that knowledge of 3D
geometry is at the heart of interaction. Our key idea is constraining and
regularizing grasping interaction learning through 3D geometry prediction.
Specifically, we formulate the learning of deep geometry-aware grasping model
in two steps: First, we learn to build mental geometry-aware representation by
reconstructing the scene (i.e., 3D occupancy grid) from RGBD input via
generative 3D shape modeling. Second, we learn to predict grasping outcome with
its internal geometry-aware representation. The learned outcome prediction
model is used to sequentially propose grasping solutions via
analysis-by-synthesis optimization. Our contributions are fourfold: (1) To best
of our knowledge, we are presenting for the first time a method to learn a
6-DOF grasping net from RGBD input; (2) We build a grasping dataset from
demonstrations in virtual reality with rich sensory and interaction
annotations. This dataset includes 101 everyday objects spread across 7
categories, additionally, we propose a data augmentation strategy for effective
learning; (3) We demonstrate that the learned geometry-aware representation
leads to about 10 percent relative performance improvement over the baseline
CNN on grasping objects from our dataset. (4) We further demonstrate that the
model generalizes to novel viewpoints and object instances.
| [
"cs.RO",
"cs.AI",
"cs.CV",
"cs.LG"
] | cs.RO | cs.AI | Robotics;Artificial Intelligence;Computer Vision and Pattern Recognition;Machine Learning | 6,335Robotics;Artificial Intelligence;Computer Vision and Pattern Recognition;Machine Learning
|
hep-ex/9510006 | An upper limit on the branching ratio for the decay $K^+ \! \rightarrow \!
\pi^+ \nu \overline{\nu}$ is set at $2.4 \times 10^{-9}$ at the 90\% C.L. using
pions in the kinematic region $214~{\rm MeV}/c < P_\pi < 231~{\rm MeV}/c$. An
upper limit of $5.2 \times 10^{-10}$ is found on the branching ratio for decays
$K^+ \! \rightarrow \! \pi^+ X^0$, where $X^0$ is any massless, weakly
interacting neutral particle. Limits are also set for cases where $M_{X^0}>0$.
| [
"hep-ex"
] | hep-ex | High Energy Physics - Experiment | 3,059High Energy Physics - Experiment
|
|
2305.06215 | When the Orthogonal Chebyshev Sliding Technique was introduced it was applied
to a portfolio of swaps and swaptions within the context of the FRTB-IMA
capital calculation. The computational cost associated to the computation of
the ES values - an essential component of the capital caluclation under
FRTB-IMA - was reduced by more than $90\%$ while passing PLA tests.
This paper extends the use of the Orthogonal Chebyshev Sliding Technique to
portfolios of equity autocallables defined over a range of spot underlyings.
Results are very positive as computational reductions are of about $90\%$ with
passing PLA metrics.
Since equity autocallables are a commonly traded exotic trade type, with
significant FRTB-IMA computational costs, the extension presented in this paper
constitutes an imporant step forward in tackling the computational challenges
associated to an efficient FRTB-IMA implementation.
| [
"q-fin.RM",
"q-fin.CP"
] | q-fin.RM | q-fin.CP | Risk Management;Computational Finance | 6,313Risk Management;Computational Finance
|
hep-ph/9506318 | The measured masses of the three charge states of the charmed $\Sigma_c$
baryon are found to be in disagreement with a sum rule based on the quark
model, but relying on no detailed assumptions about the form of the
interaction. This poses a significant problem for the charmed baryon sector of
the quark model. Other relations among charmed baryon masses are also
discussed.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
1311.3041 | We study quantum phase transitions in the asymmetric variation of the
three-leg Heisenberg tube for half-odd-integer spin, with a modulation of one
of the rung exchange couplings $J'_\perp$ while the other two are kept constant
$J_\perp$. We focus on the strong rung-coupling regime $J_\perp \gg
J_\parallel$, where $J_\parallel$ is the leg coupling, and analyze the
effective spin-orbital model with a transverse crystal field in detail.
Applying the Abelian bosonization to the effective model, we find that the
system is in the dimer phase for the general half-odd-integer-spin cases
without the rung modulation; the phase transition between the dimer and
Tomonaga-Luttinger-liquid phases induced by the rung modulation is of the
SU(2)-symmetric Berezinskii-Kosterlitz-Thouless type. Moreover, we perform a
level spectroscopy analysis for the effective model for spin-1/2 using exact
diagonalization, to determine the precise transition point $| J'_\perp -
J_\perp| /J_\parallel \sim 0.283$ in the strong rung-coupling limit. The
presence of the dimer phase in a small but finite region is also confirmed by a
density-matrix renormalization group calculation on the original spin-tube
model.
| [
"cond-mat.str-el",
"cond-mat.stat-mech"
] | cond-mat.str-el | cond-mat.stat-mech | Strongly Correlated Electrons;Statistical Mechanics | 7,046Strongly Correlated Electrons;Statistical Mechanics
|
1007.2080 | It was proved that for any finite set of elements of a free product of
residually finite groups such that no two of them belong to conjugate cyclic
subgroups and each of them do not belong to a subgroup which is conjugate a to
free factor there exists a homomorphism of the free product onto a finite group
such that the order of the image of each fixed element is an arbitrary multiple
of a constant number.
| [
"math.GR"
] | math.GR | Group Theory | 2,913Group Theory
|
|
2112.03997 | There is a growing trend for enterprise-level Internet of Things (IoT)
applications requiring real-time horizontally scalable data processing
platforms. Real-time processing platforms receiving data streams from sensor
networks (e.g., autonomous and connected vehicles, smart security for
businesses and homes, smartwatches, fitness trackers, and other wearables)
require distributed MQTT brokers. This case study presents an IoT data
streaming testbed platform prepared for the Czech Post. The presented platform
has met the throughput requirement of 2 million messages per 24 hours
(comprising SMS and emails). The tested MQTT broker runs on a single virtual
node of a horizontally scalable testbed platform. Soon the Czech Post will
modernise its eServices to increase package deliveries aligned with eCommerce
and eGovernment demands. The presented testbed platform fulfils all
requirements, and it is also capable of processing thousands of messages per
second. The presented platform and concepts are transferable to healthcare
systems, transport operations, the automotive industry, and other domains such
as smart cities.
| [
"cs.DC",
"cs.SE"
] | cs.DC | cs.SE | Distributed, Parallel, and Cluster Computing;Software Engineering | 2,262Distributed, Parallel, and Cluster Computing;Software Engineering
|
2006.15749 | Sr$_2$CuTeO$_6$ is a square-lattice N\'eel antiferromagnet with superexchange
between first-neighbor $S=1/2$ Cu spins mediated by plaquette centered Te ions.
Substituting Te by W, the affected impurity plaquettes have predominantly
second-neighbor interactions, thus causing local magnetic frustration. Here we
report a study of Sr$_2$CuTe$_{1-x}$W$_x$O$_6$ using neutron diffraction and
$\mu$SR techniques, showing that the N\'eel order vanishes already at $x =
0.025 \pm 0.005$. We explain this extreme order suppression using a
two-dimensional Heisenberg spin model, demonstrating that a W-type impurity
induces a deformation of the order parameter that decays with distance as
$1/r^2$ at temperature $T=0$. The associated logarithmic singularity leads to
loss of order for any $x>0$. Order for small $x>0$ and $T>0$ is induced by weak
interplane couplings. In the nonmagnetic phase of Sr$_2$CuTe$_{1-x}$W$_x$O$_6$,
the $\mu$SR relaxation rate exhibits quantum critical scaling with a large
dynamic exponent, $z \approx 3$, consistent with a random-singlet state.
| [
"cond-mat.str-el"
] | cond-mat.str-el | Strongly Correlated Electrons | 6,979Strongly Correlated Electrons
|
|
1302.2379 | This is the second in a series of four papers (with research announcement
posted on this arXiv) that together develop a decomposition theory for
subgroups of Out(F_n). In this paper we relativize the "Kolchin-type theorem"
from the work of Bestvina, Feighn, and Handel on the Tits alternative, which
describes a decomposition theory for subgroups H of Out(F_n) all of whose
elements have polynomial growth.
The Relative Kolchin Theorem allows subgroups H whose elements have
exponential growth, as long as all such exponential growth is cordoned off in
some free factor system F which is invariant under every element of H. The
conclusion is that a certain finite index subgroup of H has an invariant
filtration by free factor systems going from F up to the full free factor
system by individual steps each of which is a "one-edge extension".
We also study the kernel of the action of Out(F_n) on homology with Z/3
coefficients, and we prove Theorem B from the research announcement, which
describes strong finite permutation behavior of all elements of this kernel.
| [
"math.GR",
"math.GT"
] | math.GR | math.GT | Group Theory;Geometric Topology | 2,950Group Theory;Geometric Topology
|
1001.3264 | Stable cross-sections of multi-walled carbon nanotubes subjected to
electron-beam irradiation are investigated in the realm of the continuum
mechanics approximation. The self-healing nature of sp$^2$ graphitic sheets
implies that selective irradiation of the outermost walls causes their radial
shrinkage with the remaining inner walls undamaged. The shrinking walls exert
high pressure on the interior part of nanotubes, yielding a wide variety of
radial corrugation patterns ({\it i.e.,} circumferentially wrinkling
structures) in the cross section. All corrugation patterns can be classified
into two deformation phases for which the corrugation amplitudes of the
innermost wall differ significantly.
| [
"cond-mat.mes-hall",
"cond-mat.mtrl-sci"
] | cond-mat.mes-hall | cond-mat.mtrl-sci | Mesoscale and Nanoscale Physics;Materials Science | 4,493Mesoscale and Nanoscale Physics;Materials Science
|
1504.07803 | This article discusses an experience of teaching Calculus classes for the
freshmen students enrolled at Sungkyunkwan University, one of the private
universities in South Korea. The teaching and learning approach is a balance
combination between the teacher-oriented traditional style of lecturing and
other activities that encourage students for active learning and classroom
participation. Based on the initial observation during several semesters, some
anecdotal evidences show that students' learning is improved after implementing
this student-oriented active learning approach, albeit a longer period of time
is definitely needed to transform general students' attitude from passive
learners to active ones.
| [
"math.HO"
] | math.HO | History and Overview | 3,426History and Overview
|
|
1304.4542 | We study analytically and numerically spin effects in MoS_2 monolayer
armchair quantum wires and quantum dots. The interplay between intrinsic and
Rashba spin orbit interactions induced by an electric field leads to helical
modes, giving rise to spin filtering in time-reversal invariant systems. The
Rashba spin orbit interaction can also be generated by spatially varying
magnetic fields. In this case, the system can be in a helical regime with
nearly perfect spin polarization. If such a quantum wire is brought into
proximity to an s-wave superconductor, the system can be tuned into a
topological phase, resulting in midgap Majorana fermions localized at the wire
ends.
| [
"cond-mat.mes-hall"
] | cond-mat.mes-hall | Mesoscale and Nanoscale Physics | 4,450Mesoscale and Nanoscale Physics
|
|
cond-mat/0506679 | ZnAs2 nanoclusters were fabricated by incorporation into pores of zeolite
Na-X and by laser ablation. Absorption and photoluminescence spectra of ZnAs2
nanoclusters in zeolite were measured at the temperatures of 4.2, 77 and 293 K.
Both absorption and PL spectra consist of two bands which demonstrate the blue
shift from the line of free exciton in bulk crystal. We performed the
calculations aimed to find the most stable clusters in the size region up to
size of the zeolite Na-X supercage. The most stable clusters are (ZnAs2)6 and
(ZnAs2)8 with binding energies of 7.181 eV and 8.012 eV per (ZnAs2)1 formula
unit respectively. Therefore, we attributed two bands observed in absorption
and PL spectra to these stable clusters. The measured Raman spectrum of ZnAs2
clusters in zeolite was explained to be originated from (ZnAs2)6 and (ZnAs2)8
clusters as well. The PL spectrum of ZnAs2 clusters produced by laser ablation
consists of a single band which has been attributed to emission of (ZnAs2)8
cluster.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
2311.04515 | We show that Lurie's results on Tannaka duality for geometric stacks hold
without any tameness hypotheses. We deduce this as a consequence of an
affineness theorem in the theory of sheaves of categories. This affineness
result is also applied to the study of tensor product and integral transform
formulas for categories of quasicoherent sheaves.
| [
"math.AG",
"math.AT",
"math.CT"
] | math.AG | math.AT | Algebraic Geometry;Algebraic Topology;Category Theory | 51Algebraic Geometry;Algebraic Topology;Category Theory
|
1612.06985 | Rare leptonic kaon and pion decays $K^+(\pi^+) \to \mu^+\, \nu_{\mu}\, e^+
e^-$ can be used to probe a dark photon of mass ${\cal O}(10)$~MeV, with the
background coming from the mediation of a virtual photon. This is most relevant
for the 16.7-MeV dark photon proposed to explain a 6.8$\sigma$ anomaly recently
observed in $^8$Be transitions by the Atomki Collaboration. We evaluate the
reach of future experiments for different scenarios of how the dark photon
couples with the standard model particles, and show that a great portion of the
preferred 16.7-MeV dark photon parameter space can be decisively probed. We
also show the use of angular distributions to further distinguish the signal
from the background.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2111.12665 | This paper considers a novel multi-agent linear stochastic approximation
algorithm driven by Markovian noise and general consensus-type interaction, in
which each agent evolves according to its local stochastic approximation
process which depends on the information from its neighbors. The
interconnection structure among the agents is described by a time-varying
directed graph. While the convergence of consensus-based stochastic
approximation algorithms when the interconnection among the agents is described
by doubly stochastic matrices (at least in expectation) has been studied, less
is known about the case when the interconnection matrix is simply stochastic.
For any uniformly strongly connected graph sequences whose associated
interaction matrices are stochastic, the paper derives finite-time bounds on
the mean-square error, defined as the deviation of the output of the algorithm
from the unique equilibrium point of the associated ordinary differential
equation. For the case of interconnection matrices being stochastic, the
equilibrium point can be any unspecified convex combination of the local
equilibria of all the agents in the absence of communication. Both the cases
with constant and time-varying step-sizes are considered. In the case when the
convex combination is required to be a straight average and interaction between
any pair of neighboring agents may be uni-directional, so that doubly
stochastic matrices cannot be implemented in a distributed manner, the paper
proposes a push-sum-type distributed stochastic approximation algorithm and
provides its finite-time bound for the time-varying step-size case by
leveraging the analysis for the consensus-type algorithm with stochastic
matrices and developing novel properties of the push-sum algorithm. Distributed
temporal difference learning is discussed as an illustrative application.
| [
"cs.LG"
] | cs.LG | Machine Learning | 3,882Machine Learning
|
|
2210.11748 | To develop a quantitative reaction simulator, data assimilation was performed
using high-resolution time-of-flight mass spectrometry (TOF-MS) data applied to
GaN metalorganic vapor phase epitaxy system. Incorporating ab initio knowledge
into the optimization successfully reproduces not only the concentration of
CH$_4$ (an impurity precursor) as an objective variable but also known reaction
pathways. The simulation results show significant production of GaH$_3$, a
precursor of GaN, which has been difficult to detect in TOF-MS experiments. Our
proposed approach is expected to be applicable to other applied physics fields
that require quantitative prediction that goes beyond ab initio reaction rates.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
astro-ph/0703142 | This paper reports on single-pulse radio observations of PSR B1702-19 and
their implications for pulsar emission theories. These observations were made
with the Westerbork Synthesis Radio Telescope at 1380 and 328 MHz. The PA-swing
is used to constrain possible geometries of the pulsar and the single-pulse
data is analysed for subpulse modulation correlations between the main pulse
and interpulse. We confirm earlier conclusions that the dipole axis of this
pulsar is almost perpendicular to its rotation axis, and report that both its
main pulse and interpulse are modulated with a periodicity around 10.4 times
the pulsar's rotation. Allowing for the half-period delay between main pulse
and interpulse the modulation is found to be precisely in phase. Despite small
secular variations in the periodicity, the phase-locking continues over all
timescales ranging up to several years. The precision of the phase locking is
difficult for current emission theories to explain if the main pulse and
interpulse originate from opposing magnetic poles. We therefore also explore
the possibility of a bidirectional model, in which all the modulated emission
comes from one pole, but is seen from two sides and slightly displaced by
aberration and time-delay. In this model the unmodulated emission is directed
to us from the opposite pole, requiring the emission of the main pulse to
originate from two different poles. This is difficult to reconcile with the
observed smooth PA-swing. Whichever model turns out to be correct, the answer
will have important implications for emission theories.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
1511.05907 | A fully dynamic three-layer active constrained layer (ACL) beam is modeled
for cantilevered boundary conditions by using a thorough variational approach.
The Rao-Nakra thin compliant layer assumptions are adopted to model the
sandwich structure, and all magnetic effects for the piezoelectric layers are
retained. The piezoelectric layers are activated by two different voltage
sources. When there are no "mechanical" boundary forces acting in the
longitudinal direction, it is shown that the system with certain parameter
combinations is not uniformly strongly stabilizable by the $B^*-$type feedback
controller, which is the total current accumulated at the electrodes for the
piezoelectric layers. However, as the magnetic effects are ignored
(electrostatic assumption), the closed-loop system with all mechanical feedback
controllers is shown to be uniformly exponentially stable.
| [
"math.AP"
] | math.AP | Analysis of PDEs | 205Analysis of PDEs
|
|
1812.05311 | Factorization of groups into Zappa-Szep product, or more generally into
k-fold Zappa-Szep product of its subgroups, is an interesting problem, since it
eases the multiplication of two elements in a group, and has recently been
applied for public-key cryptography as well. We give a generalization of the
k-fold Zappa-Szep product of cyclic groups, which we call OGS decomposition. It
is easy to see that existence of an OGS decomposition for all the composition
factors of a non-abelian group G implies the existence of an OGS for G itself.
Since the composition factors of a soluble group are cyclic groups, it
obviously has an OGS decomposition. Therefore, the question of the existence of
an OGS decomposition is interesting for non-soluble groups. The Jordan-Holder
Theorem motivates us to consider an existence of an OGS decomposition for the
finite simple groups. In 1993, Holt and Rowley showed that PSL_{2}(q) and
PSL_{3}(q) can be expressed as a product of cyclic groups. In this paper, we
consider an OGS decomposition of PSL_{2}(q) from a point of view different than
that of Holt and Rowley. We look at its connection to the BN-pair decomposition
of the group. This connection leads to sequences over F_{q}, which can be
defined recursively, with very interesting properties, and which are closely
connected to the Dickson and to the Chebyshev polynomials. Since every finite
simple group of Lie-type has $BN-pair$ decomposition, the ideas of the paper
might be generalized to further simple groups of Lie-type.
| [
"math.GR"
] | math.GR | Group Theory | 2,913Group Theory
|
|
1208.3078 | We consider one-dimensional stochastic differential equations with
generalized drift which involve the local time $L^X$ of the solution process:
X_t = X_0 + \int_0^t b(X_s) dB_s + \int_\mathbb{R} L^X(t,y) \nu(dy), where b
is a measurable real function, $B$ is a Wiener process and $\nu$ denotes a set
function which is defined on the bounded Borel sets of the real line
$\mathbb{R}$ such that it is a finite signed measure on $\mathscr{B}([-N,N])$
for every $N \in \mathbb{N}$. This kind of equation is, in dependence of using
the right, the left or the symmetric local time, usually studied under the atom
condition $\nu({x}) < 1/2$, $\nu({x}) > -1/2$ and $|\nu({x})| < 1$,
respectively. This condition allows to reduce an equation with generalized
drift to an equation without drift and to derive conditions on existence and
uniqueness of solutions from results for equations without drift. The main aim
of the present note is to treat the cases $\nu({x}) \geq 1/2$, $\nu({x}) \leq
-1/2$ and $|\nu({x})| \geq 1$, respectively, for some $x \in \mathbb{R}$, and
we give a complete description of the features of equations with generalized
drift and their solutions in these cases.
| [
"math.PR"
] | math.PR | Probability | 5,709Probability
|
|
2106.06402 | We study two well-known $SU(N)$ chiral gauge theories with fermions in the
symmetric, anti-symmetric and fundamental representations. We give a detailed
description of the global symmetry, including various discrete quotients.
Recent work argues that these theories exhibit a subtle mod 2 anomaly, ruling
out certain phases in which the theories confine without breaking their global
symmetry, leaving a gapless composite fermion in the infra-red. We point out
that no such anomaly exists. We further exhibit an explicit path to the gapless
fermion phase, showing that there is no kinematic obstruction to realising
these phases.
| [
"hep-th",
"hep-lat",
"hep-ph"
] | hep-th | hep-lat | High Energy Physics - Theory;High Energy Physics - Lattice;High Energy Physics - Phenomenology | 3,344High Energy Physics - Theory;High Energy Physics - Lattice;High Energy Physics - Phenomenology
|
nucl-th/9906001 | Proton-neutron (p-n) interactions and its various aspects in $N\approx Z$
nuclei of $g_{9/2}$- and $f_{7/2}$ subshell are studied using a schematic model
interaction with four force parameters proposed recently. It is shown that the
model interaction well reproduces observed physical quantities: the double
differences of binding energies, symmetry energy, Wigner energy, odd-even mass
difference and separation energy, which testifies the reliability of the model
interaction and its p-n interactions.
First of all, the double differences of binding energies are used for probing
the p-n interactions. The analysis reveals different contributions of the
isoscalar and isovector p-n pairing interactions to two types of double
difference of binding energies, and also indicates the importance of a unique
form of isoscalar p-n pairing force with all $J$ components. Next, it is shown
that this p-n force is closely related to the symmetry energy and the Wigner
energy. Other calculations demonstrate significant roles of p-n interactions in
the odd-even mass difference and in the separation energy at $N=Z$.
| [
"nucl-th"
] | nucl-th | Nuclear Theory | 4,876Nuclear Theory
|
|
1405.0220 | Information multiplexing is important for biomedical imaging and chemical
sensing. In this paper, we report a microscopy imaging technique, termed
state-multiplexed Fourier ptychography (FP), for information multiplexing and
coherent-state decomposition. Similar to a typical Fourier ptychographic
setting, we use an array of light sources to illuminate the sample from
different incident angles and acquire corresponding low-resolution images using
a monochromatic camera. In the reported technique, however, multiple light
sources are lit up simultaneously for information multiplexing, and the
acquired images thus represent incoherent summations of the sample transmission
profiles corresponding to different coherent states. We show that, by using the
state-multiplexed FP recovery routine, we can decompose the incoherent mixture
of the FP acquisitions to recover a high-resolution sample image. We also show
that, color-multiplexed imaging can be performed by simultaneously turning on
R/G/B LEDs for data acquisition. The reported technique may provide a solution
for handling the partially coherent effect of light sources used in Fourier
ptychographic imaging platforms. It can also be used to replace spectral
filter, gratings or other optical components for spectral multiplexing and
demultiplexing. With the availability of cost-effective broadband LEDs, the
reported technique may open up exciting opportunities for computational
multispectral imaging.
| [
"physics.optics"
] | physics.optics | Optics | 5,146Optics
|
|
2003.09996 | For safe navigation around pedestrians, automated vehicles (AVs) need to plan
their motion by accurately predicting pedestrians trajectories over long time
horizons. Current approaches to AV motion planning around crosswalks predict
only for short time horizons (1-2 s) and are based on data from pedestrian
interactions with human-driven vehicles (HDVs). In this paper, we develop a
hybrid systems model that uses pedestrians gap acceptance behavior and constant
velocity dynamics for long-term pedestrian trajectory prediction when
interacting with AVs. Results demonstrate the applicability of the model for
long-term (> 5 s) pedestrian trajectory prediction at crosswalks. Further we
compared measures of pedestrian crossing behaviors in the immersive virtual
environment (when interacting with AVs) to that in the real world (results of
published studies of pedestrians interacting with HDVs), and found similarities
between the two. These similarities demonstrate the applicability of the hybrid
model of AV interactions developed from an immersive virtual environment (IVE)
for real-world scenarios for both AVs and HDVs.
| [
"cs.RO",
"cs.CY",
"cs.HC"
] | cs.RO | cs.CY | Robotics;Computers and Society;Human-Computer Interaction | 6,366Robotics;Computers and Society;Human-Computer Interaction
|
1306.3037 | Calorimeters with a high granularity are a fundamental requirement of the
Particle Flow paradigm. This paper focuses on the prototype of a hadron
calorimeter with analog readout, consisting of thirty-eight scintillator layers
alternating with steel absorber planes. The scintillator plates are finely
segmented into tiles individually read out via Silicon Photomultipliers. The
presented results are based on data collected with pion beams in the energy
range from 8GeV to 100GeV. The fine segmentation of the sensitive layers and
the high sampling frequency allow for an excellent reconstruction of the
spatial development of hadronic showers. A comparison between data and Monte
Carlo simulations is presented, concerning both the longitudinal and lateral
development of hadronic showers and the global response of the calorimeter. The
performance of several GEANT4 physics lists with respect to these observables
is evaluated.
| [
"physics.ins-det",
"hep-ex"
] | physics.ins-det | hep-ex | Instrumentation and Detectors;High Energy Physics - Experiment | 3,647Instrumentation and Detectors;High Energy Physics - Experiment
|
astro-ph/0308537 | LUNA, Laboratory for Underground Nuclear Astrophysics at Gran Sasso, is
measuring fusion cross sections down to the energy of the nucleosynthesis
inside stars. Outstanding results obtained up to now are the cross-section
measurements within the Gamow peak of the Sun of $^{3}He(^{3}He,2p)^{4}He$ and
the $D(p,\gamma)^{3}He$. The former plays a big role in the proton-proton
chain, largely affecting the calculated solar neutrino luminosity, whereas the
latter is the reaction that rules the proto-star life during the pre-main
sequence phase. The implications of such measurements will be discussed.
Preliminary results obtained last year on the study of
$^{14}N(p,\gamma)^{15}O$, the slowest reaction of the CNO cycle, will also be
shown.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
hep-ph/0701194 | If annihilating MeV-scale dark matter particles are responsible for the
observed 511 keV emission from the Galactic bulge, then new light gauge bosons
which mediate the dark matter annihilations may have other observable
consequences. In particular, if such a gauge boson exists and has even very
small couplings to Standard Model neutrinos, cosmic neutrinos with ~TeV
energies will scatter with the cosmic neutrino background through resonant
exchange, resulting in a distinctive spectral absorption line in the
high-energy neutrino spectrum. Such a feature could potentially be detected by
future high-energy neutrino telescopes.
| [
"hep-ph",
"astro-ph"
] | hep-ph | astro-ph | High Energy Physics - Phenomenology;Astrophysics | 3,131High Energy Physics - Phenomenology;Astrophysics
|
1209.6128 | Mean-field theory of non-interacting disordered electron systems is widely
and successfully used to describe equilibrium properties of alloys in the whole
range of disorder strengths. It, however, fails to take into account effects of
quantum coherence and localizing back-scattering effects when applied to
transport phenomena. We present an approximate scheme extending the mean-field
theory for one-electron properties in that it offers a formula for the
two-particle vertex and the electrical conductivity non-perturbatively
including the leading-order vertex corrections in a way that the approximation
remains consistent and the conductivity non-negative in all disorder regimes.
| [
"cond-mat.dis-nn",
"cond-mat.str-el"
] | cond-mat.dis-nn | cond-mat.str-el | Disordered Systems and Neural Networks;Strongly Correlated Electrons | 2,190Disordered Systems and Neural Networks;Strongly Correlated Electrons
|
1704.08581 | We propose a model with $U(1)_{B-L}$ gauge symmetry and several new fermions
in no conflict with anomaly cancellation where the neutrino masses are given by
the vacuum expectation value of Higgs triplet induced at the one-loop level.
The new fermions are odd under discrete $Z_2$ symmetry and the lightest one
becomes dark matter candidate. We find that the mass of dark matter is
typically $O(1)$-$O(10)$ GeV. Then relic density of the dark matter is
discussed.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
1705.00526 | It is reported on growth of mm-sized single-crystals of the low-dimensional S
= 1/2 spin compound Cu6(Ge,Si)6O18.6H2O by a diffusion technique in aqueous
solution. A route to form Si-rich crystals down to possibly dioptase, the pure
silicate, is discussed. Further, the assignment of dd excitations from UV-VIS
spectra of the hexahydrate and the fully dehydrated compound is proposed in
comparison to dioptase and selected Cu(II) oxo-compounds using bond strength
considerations. Non-doped cuprates as layer compounds show higher excitation
energies than the title compound. However, when the antiferromagnetic
interaction energy as Jzln(2) is taken into account for cuprates, a single
linear relationship between the Dqe excitation energy and equatorial Cu(II)-O
bond strength is confirmed for all compounds. A linear representation is also
confirmed between 2A1g energies and a function of axial and equatorial Cu-O
bond distances, when auxiliary axial bonds are used for four-coordinated
compounds. The quotient Dt/Ds of experimental orbital energies deviating from
the general trend to smaller values indicates the existence of H2O respectively
Cl1- axial ligands in comparison to oxo-ligands, whereas larger Dt/Dqe values
indicate missing axial bonds. The quotient of the excitation energy 2A1g by
2x2Eg-2B2g allows to check for correctness of the assignment and to distinguish
between axial oxo-ligands and others like H2O or Cl1-. Some assignments
previously reported were corrected.
| [
"cond-mat.mtrl-sci",
"cond-mat.other",
"physics.chem-ph"
] | cond-mat.mtrl-sci | cond-mat.other | Materials Science;Other Condensed Matter;Chemical Physics | 4,356Materials Science;Other Condensed Matter;Chemical Physics
|
0903.2115 | We study the all-optical switching behavior of one-dimensional
metal-dielectric photonic crystals due to the nonlinearity of the free metal
electrons. A polychromatic pump-probe setup is used to determine the wavelength
and pump intensity dependence of the ultrafast transmission suppression as well
as the dynamics of the process on a subpicosecond timescale. We find ultrafast
(sub-picosecond) as well as a slow (millisecond) behavior. We present a model
of the ultrafast dynamics and nonlinear response which can fit the measured
data well and allows us to separate the thermal and the electronic response of
the system.
| [
"cond-mat.other"
] | cond-mat.other | Other Condensed Matter | 5,360Other Condensed Matter
|
|
math/0606610 | In the Frobenius problem we are given a set of coprime, positive integers
$a_1, a_2,...,a_k$, and are interested in the set of positive numbers NR that
have no representation by the linear form $\sum_i a_ix_i$ in nonnegative
integers $x_1, x_2,...,x_k$. We give a functional relationship that completely
characterizes the set NR, and apply it to the case when the numbers are in an
arithmetic progression.
| [
"math.NT",
"math.RT"
] | math.NT | math.RT | Number Theory;Representation Theory | 4,998Number Theory;Representation Theory
|
1512.06443 | We elaborate on the ambient space approach to boundary values of $AdS_{d+1}$
gauge fields and apply it to massless fields of mixed-symmetry type. In the
most interesting case of odd-dimensional bulk the respective leading boundary
values are conformal gauge fields subject to the invariant equations. Our
approach gives a manifestly conformal and gauge covariant formulation for these
fields. Although such formulation employs numerous auxiliary fields, it comes
with a systematic procedure for their elimination that results in a more
concise formulation involving only a reasonable set of auxiliaries, which
eventually (at least in principle) can be reduced to the minimal formulation in
terms of the irreducible Lorentz tensors. The simplest mixed-symmetry field,
namely, the rank-3 tensor associated to the two-row Young diagram, is
considered in some details.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
2004.02303 | Single particle-resolved fluorescence imaging is an enabling technology in
cold-atom physics. However, so far, this technique was not available for
nanophotonic atom-light interfaces. Here, we image single atoms that are
trapped and optically interfaced using an optical nanofiber. Near-resonant
light is scattered off the atoms and imaged while counteracting heating
mechanisms via degenerate Raman cooling. We detect trapped atoms within 150 ms
and record image sequences of given atoms. Building on our technique, we
perform two experiments which are conditioned on the number and position of the
nanofiber-trapped atoms. We measure the transmission of nanofiber-guided
resonant light and verify its exponential scaling in the few-atom limit, in
accordance with Beer-Lambert's law. Moreover, depending on the interatomic
distance, we observe interference of the fields that two simultaneously trapped
atoms emit into the nanofiber. The demonstrated technique enables
post-selection and possible feedback schemes and thereby opens the road towards
a new generation of experiments in quantum nanophotonics.
| [
"quant-ph",
"physics.atom-ph"
] | quant-ph | physics.atom-ph | Quantum Physics;Atomic Physics | 5,996Quantum Physics;Atomic Physics
|
1904.13198 | Identifying noteworthy spreaders in a network is essential for understanding
the spreading process and controlling the reach of the spread in the network.
The nodes that are holding more intrinsic power to extend the reach of the
spread are important due to demand for various applications such as viral
marketing, controlling rumor spreading or get a better understanding of
spreading of the diseases. As an application of the viral marketing,
maximization of the reach with a fixed budget is a fundamental requirement in
the advertising business. Distributing a fixed number of promotional items for
maximizing the viral reach can leverage influencer detection methods. For
detecting such "influencer" nodes, there are local metrics such as degree
centrality (mostly used as in-degree centrality) or global metrics such as
k-shell decomposition or eigenvector centrality. All the methods can rank
graphs but they all have limitations and there is still no de-facto method for
influencer detection in the domain.
In this paper, we propose an extended k-shell algorithm which better utilizes
the k-shell decomposition for identifying viral spreader nodes using the
topological features of the network. We use Susceptible-Infected-Recovered
model for the simulations of the spreading process in real-life networks and
the simulations demonstrates that our approach can reach to up to 36% larger
crowds within the same network, with the same number of initial spreaders.
| [
"cs.SI",
"physics.soc-ph"
] | cs.SI | physics.soc-ph | Social and Information Networks;Physics and Society | 6,526Social and Information Networks;Physics and Society
|
2008.00085 | In this paper, we evaluate the performance of networks that use RPL (Routing
Protocols for Low Power and Lossy Networks) with TSCH (Time Slotted Channel
Hopping) and Orchestra (an autonomous method for building the TSCH schedule).
We measure the performance in the transient state when a node dies (i.e.,
removed from the network) and determine how long it takes for the network to
come back to a stable RPL tree and also what the impact is with respect to
energy consumption. Our analysis shows that the Orchestra reduces the energy
consumption when the RPL is in a transient state, like in the case of when one
of the nodes die. Furthermore, we calculate the energy consumption in the
transient state without using Orchestra, and then we make a comparison between
both outcomes. We show that Orchestra reduces energy consumption by up to
one-third compared to not using Orchestra.
| [
"cs.NI"
] | cs.NI | Networking and Internet Architecture | 4,711Networking and Internet Architecture
|
|
cond-mat/9603110 | We use the Kubo formalism to calculate the transresistivity $\rho_{21}$ for
carriers in coupled quantum wells in a large perpendicular magnetic field $B$.
We find that $\rho_{21}$ is enhanced by approximately 50--100 times over that
of the B=0 case in the interplateau regions of the integer quantum Hall effect.
The presence of both electron--electron interactions and Landau quantization
results in (i) a twin-peaked structure of $\rho_{21}(B)$ in the inter-plateau
regions at low temperatures, and, (ii) for the chemical potential at the center
of a Landau level band, a peaked temperature dependence of $\rho_{21}(T)/T^2$.
| [
"cond-mat"
] | cond-mat | Condensed Matter | 1,697Condensed Matter
|
|
1811.04803 | A colored graph is a directed graph in which nodes or edges have been
assigned colors that are not necessarily unique. Observability problems in such
graphs consider whether an agent observing the colors of edges or nodes
traversed on a path in the graph can determine which node they are at currently
or which nodes were visited earlier in the traversal. Previous research efforts
have identified several different notions of observability as well as the
associated properties of graphs for which those observability properties hold.
This paper unifies the prior work into a common framework with several new
results about relationships between those notions and associated graph
properties. The new framework provides an intuitive way to reason about the
attainable accuracy as a function of lag and time spent observing, and
identifies simple modifications to improve the observability of a given graph.
We show that one form of the graph modification problem is in NP-Complete. The
intuition of the new framework is borne out with numerical experiments. This
work has implications for problems that can be described in terms of an agent
traversing a colored graph, including the reconstruction of hidden states in a
hidden Markov model (HMM).
| [
"cs.LG",
"math.CO",
"stat.ML"
] | cs.LG | math.CO | Machine Learning;Combinatorics;Machine Learning | 4,007Machine Learning;Combinatorics;Machine Learning
|
0706.1726 | We determine $D$ and $D_s$ decay constants from lattice QCD with 2% errors, 4
times better than experiment and previous theory: $f_{D_s}$ = 241(3) MeV, $f_D$
= 207(4) MeV and $f_{D_s}/f_D$ = 1.164(11).
We also obtain $f_K/f_{\pi}$ = 1.189(7) and $(f_{D_s}/f_D)/(f_K/f_{\pi})$ =
0.979(11). Combining with experiment gives $V_{us}$=0.2262(14) and
$V_{cs}/V_{cd}$ of 4.43(41). We use a highly improved quark discretization on
MILC gluon fields that include realistic sea quarks fixing the $u/d, s$ and $c$
masses from the $\pi$, $K$, and $\eta_c$ meson masses. This allows a stringent
test against experiment for $D$ and $D_s$ masses for the first time (to within
7 MeV).
| [
"hep-lat",
"hep-ph"
] | hep-lat | hep-ph | High Energy Physics - Lattice;High Energy Physics - Phenomenology | 3,105High Energy Physics - Lattice;High Energy Physics - Phenomenology
|
1709.03734 | As low frequency band becomes more and more crowded, millimeter-wave (mmWave)
has attracted significant attention recently. IEEE has released the 802.11ad
standard to satisfy the demand of ultra-high-speed communication. It adopts
beamforming technology that can generate directional beams to compensate for
high path loss. In the Association Beamforming Training (A-BFT) phase of
beamforming (BF) training, a station (STA) randomly selects an A-BFT slot to
contend for training opportunity. Due to the limited number of A-BFT slots,
A-BFT phase suffers high probability of collisions in dense user scenarios,
resulting in inefficient training performance. Based on the evaluation of the
IEEE 802.11ad standard and 802.11ay draft in dense user scenarios of mmWave
wireless networks, we propose an enhanced A-BFT beam training and random access
mechanism, including the Separated A-BFT (SA-BFT) and Secondary Backoff A-BFT
(SBA-BFT). The SA-BFT can provide more A-BFT slots and divide A-BFT slots into
two regions by defining a new `E-A-BFT Length' field compared to the legacy
802.11ad A-BFT, thereby maintaining compatibility when 802.11ay devices are
mixed with 802.11ad devices. It can also reduce the collision probability in
dense user scenarios greatly. The SBA-BFT performs secondary backoff with very
small overhead of transmission opportunities within one A-BFT slot, which not
only further reduces collision probability, but also improves the A-BFT slots
utilization. Furthermore, we propose a three-dimensional Markov model to
analyze the performance of the SBA-BFT. The analytical and simulation results
show that both the SA-BFT and the SBA-BFT can significantly improve BF training
efficiency, which are beneficial to the optimization design of dense user
wireless networks based on the IEEE 802.11ay standard and mmWave technology.
| [
"cs.NI"
] | cs.NI | Networking and Internet Architecture | 4,711Networking and Internet Architecture
|
|
hep-lat/9712014 | We report our light hadron mass calculation based on an increased statistics
of 250 quenched gauge configurations on a (48^3 \times 64) lattice at (\beta =
6.5). Quark propagators are calculated for each of these configurations with
staggered wall source and point sink at quark mass values of (m_q = 0.01,
0.005, 0.0025) and (0.00125). We also did additional calculations to improve
our understanding of systematic biases arising from autocorrelation, source
size, and propagator calculations. Our earlier conclusions that the flavor
symmetry breaking is reduced and the ratio (m_N/m_\rho (\sim 1.25(4))) is small
remains robust.
| [
"hep-lat"
] | hep-lat | High Energy Physics - Lattice | 3,092High Energy Physics - Lattice
|
|
1907.00711 | Finding theta function (or $q$-)analogues for well-known trigonometric
identities is an interesting topic. In this paper, we first introduce the
definition of $q$-analogues for $\mathrm{tan}z$ and $\mathrm{cot}z$ and then
apply the theory of elliptic functions to establish a theta function identity.
From this identity we deduce two $q$-trigonometric identities involving
$\mathrm{tan}_{q}z$ and $\cot_{q}z,$ which are theta function analogues for two
well-known trigonometric identities concerning $\mathrm{tan}z$ and $\cot z.$
Some other $q$-trigonometric identities are also given.
| [
"math.GM"
] | math.GM | General Mathematics | 2,639General Mathematics
|
|
2307.07819 | We study the fully-strange tetraquark states with the exotic quantum numbers
$J^{PC} = 0^{+-}$ and $2^{+-}$. We construct their corresponding
diquark-antidiquark interpolating currents, and apply the QCD sum rule method
to calculate both their diagonal and off-diagonal correlation functions. The
obtained results are used to construct some mixing currents that are nearly
non-correlated, from which we extract the masses of the lowest-lying states to
be $M_{0^{+-}} = 2.45^{+0.33}_{-0.44}$ GeV and $M_{2^{+-}} =
3.07^{+0.25}_{-0.33}$ GeV. We apply the Fierz rearrangement to transform the
diquark-antidiquark currents to be the combinations of meson-meson currents,
and the obtained Fierz identities indicate that these two states may be
searched for in the $P$-wave $\phi(1020) f_0(1710)/\phi(1020) f_2^\prime(1525)
(\to \phi K \bar K / \phi \pi \pi)$ channels.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2204.13286 | Single-image super-resolution (SISR) has achieved significant breakthroughs
with the development of deep learning. However, these methods are difficult to
be applied in real-world scenarios since they are inevitably accompanied by the
problems of computational and memory costs caused by the complex operations. To
solve this issue, we propose a Lightweight Bimodal Network (LBNet) for SISR.
Specifically, an effective Symmetric CNN is designed for local feature
extraction and coarse image reconstruction. Meanwhile, we propose a Recursive
Transformer to fully learn the long-term dependence of images thus the global
information can be fully used to further refine texture details. Studies show
that the hybrid of CNN and Transformer can build a more efficient model.
Extensive experiments have proved that our LBNet achieves more prominent
performance than other state-of-the-art methods with a relatively low
computational cost and memory consumption. The code is available at
https://github.com/IVIPLab/LBNet.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
1812.07139 | Using the high-resolution observations from New Vacuum Solar Telescope (NVST)
jointly with the Solar Dynamics Observatory data, we investigate two successive
confined eruptions (Erup1 and Erup2) of a small filament in a decaying active
region on 2017 November 10. During the process of Erup1, the overlying magnetic
arcade is observed to inflate with the rising filament at beginning and then
stop the ongoing of the explosion. In the hot EUV channel, a coronal sigmoidal
structure appears during the first eruption and fade away after the second one.
The untwisting rotation and disintegration of the filament in Erup2 are clearly
revealed by the NVST H_alpha intensity data, hinting at a pre-existing twisted
configuration of the filament. By tracking two rotating features in the
filament, the average rotational angular velocity of the unwinding filament is
found to be ~10.5 degree/min. A total twist of ~1.3 pi is estimated to be
stored in the filament before the eruption, which is far below the criteria for
kink instability. In the course of several hours prior to the event, some
photospheric flux activities, including the flux convergence and cancellation,
are detected around the northern end of the filament, where some small-scale
EUV brightenings are also captured. Moreover, strongly-sheared transverse
fields are found in the cancelling magnetic features from the vector
magnetograms. Our observational results support the flux cancellation model, in
which the interaction between the converging and sheared opposite-polarity
fluxes destabilizes the filament and triggers the ensuing ejection.
| [
"astro-ph.SR"
] | astro-ph.SR | Solar and Stellar Astrophysics | 6,668Solar and Stellar Astrophysics
|
|
astro-ph/0604492 | Scalar-Tensor theories of gravity can be formulated in different frames, most
notably, the Einstein and the Jordan one. While some debate still persists in
the literature on the physical status of the different frames, a frame
transformation in Scalar-Tensor theories amounts to a local redefinition of the
metric, and then should not affect physical results. We analyze the issue in a
cosmological context. In particular, we define all the relevant observables
(redshift, distances, cross-sections, ...) in terms of frame-independent
quantities. Then, we give a frame-independent formulation of the Boltzmann
equation, and outline its use in relevant examples such as particle freeze-out
and the evolution of the CMB photon distribution function. Finally, we derive
the gravitational equations for the frame-independent quantities at first order
in perturbation theory. From a practical point of view, the present approach
allows the simultaneous implementation of the good aspects of the two frames in
a clear and straightforward way.
| [
"astro-ph",
"gr-qc",
"hep-ph",
"hep-th"
] | astro-ph | gr-qc | Astrophysics;General Relativity and Quantum Cosmology;High Energy Physics - Phenomenology;High Energy Physics - Theory | 519Astrophysics;General Relativity and Quantum Cosmology;High Energy Physics - Phenomenology;High Energy Physics - Theory
|
2005.09293 | We present a dispersive analysis with the aim to extract the $\Upsilon$-p
scattering length from $\gamma p \to \Upsilon p$ experiments. In this
framework, the imaginary part of the $\Upsilon$-p forward scattering amplitude
is obtained from $\gamma p \to \Upsilon p$ cross section measurements, and is
constrained at high energies from existing HERA and LHC data. Its real part is
calculated through a once-subtracted dispersion relation, and the subtraction
constant is proportional to the $\Upsilon$-p scattering length. We perform a
feasibility study for $\Upsilon$ photo-production experiments at an
Electron-Ion Collider and discuss the sensitivity and precision that can be
reached in the extraction of the $\Upsilon$-p scattering length.
| [
"hep-ph",
"hep-ex"
] | hep-ph | hep-ex | High Energy Physics - Phenomenology;High Energy Physics - Experiment | 3,198High Energy Physics - Phenomenology;High Energy Physics - Experiment
|
hep-ph/0304109 | We study the dynamical electroweak symmetry breaking (DEWSB) in the $D
(=6,8,...)$-dimensional bulk with compactified extra dimensions. We identify
the critical binding strength for triggering the DEWSB, based on the ladder
Schwinger-Dyson equation. In the top mode standard model with extra dimensions,
where the standard model gauge bosons and the third generation of quarks and
leptons are put in the bulk, we analyze the most attractive channel (MAC) by
using renormalization group equations (RGEs) of (dimensionless) bulk gauge
couplings and determine the effective cutoff where the MAC coupling exceeds the
critical value. We then find that the top-condensation can take place for D=8.
Combining RGEs of top-Yukawa and Higgs-quartic couplings with compositeness
conditions, we predict the top mass, $m_t=173-180$ GeV, and the Higgs mass,
$m_H=181-211$ GeV, for D=8, where we took the universal compactification scale
$1/R = 1-100$ TeV.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2205.10181 | An artificial neural-network-based subgrid-scale model using the resolved
stress, which is capable of predicting untrained decaying isotropic turbulence,
is developed. Providing the grid-scale strain-rate tensor alone as input leads
the model to predict a subgrid-scale stress tensor aligns with the strain-rate
tensor, and the model performs similar to the dynamic Smagorinsky model. On the
other hand, providing the resolved stress tensor as input in addition to the
strain-rate tensor is found to significantly improve the model in terms of the
energy spectra and probability density function of subgrid-scale dissipation.
In an attempt to apply the neural-network-based model trained for forced
homogeneous isotropic turbulence to decaying homogeneous isotropic turbulence,
special attention is given to the normalisation of the input and output
tensors. It is found that successful generalisation of the model to turbulence
at various untrained conditions is possible if the distributions of the
normalised inputs and outputs of the neural-network remain unchanged as
Reynolds numbers and grid resolution of the turbulence vary. In a posteriori
tests of the forced and the decaying homogeneous isotropic turbulence, the
developed neural-network model is found to predict turbulence statistics more
accurately and to be computationally more efficient than the conventional
dynamic models.
| [
"physics.flu-dyn"
] | physics.flu-dyn | Fluid Dynamics | 2,452Fluid Dynamics
|
|
1507.06473 | We present a detailed investigation of the flaring activity observed from a
BL Lac object, S5 0716+714 , during its brightest ever optical state in the
second half of January 2015. Observed almost simultaneously in the optical,
X-rays and {\gamma}-rays, a significant change in the degree of optical
polarization (PD) and a swing in the position angle (PA) of polarization were
recorded. A detection in the TeV (VHE) was also reported by the MAGIC
consortium during this flaring episode. Two prominent sub-flares, peaking about
5-days apart, were seen in almost all the energy bands. The multi-wavelength
light-curves, spectral energy distribution (SED) and polarization are modeled
using the time-dependent code developed by Zhang et al. (2014). This model
assumes a straight jet threaded by large scale helical magnetic fields taking
into account the light travel time effects, incorporating synchrotron flux and
polarization in 3D geometry. The rapid variation in PD and rotation in PA are
most likely due to re-connections happening in the emission region in the jet,
as suggested by the change in the ratio of toroidal to poloidal components of
magnetic field during quiescent and flaring states.
| [
"astro-ph.HE"
] | astro-ph.HE | High Energy Astrophysical Phenomena | 2,990High Energy Astrophysical Phenomena
|
|
2310.17103 | Fresnel incoherent correlation holography (FINCH) is a well-established
digital holography technique for 3D imaging of objects illuminated by spatially
incoherent light. FINCH has a higher lateral resolution of 1.5 times that of
direct imaging systems with the same numerical aperture. However, the other
imaging characteristics of FINCH such as axial resolution, temporal resolution,
light throughput and signal to noise ratio (SNR) are lower than those of direct
imaging system. Different techniques were developed by researchers around the
world to improve the imaging characteristics of FINCH while retaining the
inherent higher lateral resolution of FINCH. However, most of the solutions
developed to improve FINCH presented additional challenges. In this study, we
optimized FINCH in the framework of coded aperture imaging. Two recently
developed computational methods such as transport of amplitude into phase based
on Gerchberg Saxton algorithm (TAP-GSA) and Lucy-Richardson-Rosen algorithm
were applied to improve light throughput and image reconstruction respectively.
The above implementation improved the axial resolution, time resolution and SNR
of FINCH close to those of direct imaging while retaining the high lateral
resolution. A point spread function (PSF) engineering technique has been
implemented to prevent the low lateral resolution problem associated with the
PSF recorded using pinholes with a large diameter. We believe that the above
developments are beyond the state-of-the-art of existing FINCH-scopes.
| [
"physics.optics"
] | physics.optics | Optics | 5,146Optics
|
|
1712.07615 | The Pl\"unnecke-Ruzsa inequality is a fundamental tool to control the growth
of finite subsets of abelian groups under repeated addition and subtraction.
Other tools to handle sumsets have gained applicability by being extended to
more general subsets of more general groups. This motivates extending the
Pl\"unnecke-Ruzsa inequality, in particular to measurable subsets of compact
abelian groups by replacing the cardinality with the Haar probability measure.
This objective is related to the question of the stability of classes of Haar
measurable sets under addition. In this direction the class of analytic sets is
a natural one to work with. We prove a Pl\"unnecke-Ruzsa inequality for
K-analytic sets in general compact (Hausdorff) abelian groups. We also discuss
further extensions, some of which raise questions of independent interest in
descriptive topology.
| [
"math.CO",
"math.GN"
] | math.CO | math.GN | Combinatorics;General Topology | 1,069Combinatorics;General Topology
|
2112.07463 | Speaker diarization is connected to semantic segmentation in computer vision.
Inspired from MaskFormer \cite{cheng2021per} which treats semantic segmentation
as a set-prediction problem, we propose an end-to-end approach to predict a set
of targets consisting of binary masks, vocal activities and speaker vectors.
Our model, which we coin \textit{DiFormer}, is mainly based on a speaker
encoder and a feature pyramid network (FPN) module to extract multi-scale
speaker features which are then fed into a transformer encoder-decoder to
predict a set of diarization targets from learned query embedding. To account
for temporal characteristics of speech signal, bidirectional LSTMs are inserted
into the mask prediction module to improve temporal consistency. Our model
handles unknown number of speakers, speech overlaps, as well as vocal activity
detection in a unified way. Experiments on multimedia and meeting datasets
demonstrate the effectiveness of our approach.
| [
"cs.SD",
"eess.AS"
] | cs.SD | eess.AS | Sound;Audio and Speech Processing | 6,734Sound;Audio and Speech Processing
|
1208.4133 | Motivated by the spate of recent experimental and theoretical interest in
Mott insulating S=1 triangular lattice magnets, we consider a model S=1
Hamiltonian on a triangular lattice interacting with rotationally symmetric
biquadratic interactions. We show that the partition function of this model can
be expressed in terms of configurations of three colors of tightly-packed,
closed loops with {\em non-negative} weights, which allows for efficient
quantum Monte Carlo sampling on large lattices. We find the ground state has
spin nematic order, i.e. it spontaneously breaks spin rotation symmetry but
preserves time reversal symmetry. We present accurate results for the
parameters of the low energy field theory, as well as finite-temperature
thermodynamic functions.
| [
"cond-mat.str-el"
] | cond-mat.str-el | Strongly Correlated Electrons | 6,979Strongly Correlated Electrons
|
|
2310.02293 | Urban land growth presents a major sustainability challenge, yet its growth
patterns and dynamics remain unclear. We quantified urban land evolution by
analyzing its statistical distribution in 14 regions and countries over 29
years. The results show a converging temporal trend in urban land expansion
from sub-country to global scales, characterized by a coherent shift of urban
area distributions from initial power law to exponential distributions, with
the consequences of reduced system stability and resilience, and increased
exposure of urban populations to extreme heat and air pollution. These changes
are attributed to the increased influence from external economies of scale
associated with globalization and are predicted to intensify in the future. The
findings will advance urban science and direct current land urbanization
practices toward sustainable development, especially in developing regions and
medium-size cities.
| [
"physics.soc-ph"
] | physics.soc-ph | Physics and Society | 5,463Physics and Society
|
|
2305.14845 | We consider a generalization of the quintessence type scalar field
cosmological models, by adding a multiplicative dissipative term in the scalar
field Lagrangian, which is represented in an exponential form. The generalized
dissipative Klein-Gordon equation is obtained from the variational principle in
a covariant form. The energy-momentum tensor of the dissipative scalar field is
also obtained from the dissipative Lagrangian. The generalized Friedmann
equations in the presence of the dissipative scalar field are obtained for a
specific form of dissipation, with the dissipation exponent represented as the
time integral of the product of the Hubble function, and of a function
describing the dissipative properties of the scalar field. Several cosmological
models, corresponding to different choices of the dissipation function, and of
the scalar field potential, are considered in detail. The evolutions of the
basic cosmological parameters (Hubble function, deceleration parameter etc.)
are investigated by using both analytical and numerical techniques. A
comparison with the observational data for the Hubble function, and with the
predictions of the standard $\Lambda$CDM paradigm is also presented for each
dissipative scalar field model. In the large time limit the model describes an
accelerating Universe, with the effective negative pressure induced by the
dissipative effects associated to the scalar field. Accelerated expansion in
the absence of the scalar field potential is also possible, with the kinetic
term dominating the expansionary evolution. The dissipative scalar field models
describe well the observational data, with the free parameters of the model
obtained by a trial and error method. The obtained results show that the
dissipative scalar field model offers an effective dynamical possibility for
explaining the recent cosmological observational data.
| [
"gr-qc",
"astro-ph.CO",
"hep-th"
] | gr-qc | astro-ph.CO | General Relativity and Quantum Cosmology;Cosmology and Nongalactic Astrophysics;High Energy Physics - Theory | 2,713General Relativity and Quantum Cosmology;Cosmology and Nongalactic Astrophysics;High Energy Physics - Theory
|
1807.02459 | The discovery of Weyl and Dirac semimetals has produced a number of dramatic
physical effects, including the chiral anomaly and topological Fermi arc
surface states. We point out that a very different but no less dramatic
physical effect is also to be found in these materials: discrete scale
invariance. This invariance leads to bound state spectra for Coulomb impurities
that repeat when the binding energy is changed by a fixed factor, reminiscent
of fractal behavior. We show that this effect follows from the peculiar
dispersion relation in Weyl and Dirac semimetals. It is observed when such a
material is placed in very strong magnetic field B: there are oscillations in
the magnetoresistivity somewhat similar to Shubnikov-de Haas oscillations but
with a periodicity in ln B rather than 1/B. These oscillations should be
present in other thermodynamic and transport properties. The oscillations have
now been seen in three topological semimetals: ZrTe$_{5}$, TaAs, and Bi.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
1309.2996 | It is well known that the scalar field Green's function in odd dimensions has
a tail, i.e. a non-zero support inside the light cone, which in turn implies
that the Huygens' principle is violated. However, the reason behind this
behavior is still not quite clear. In this paper we shed more light on the
physical origin of the tail by regularizing the term which is usually ignored
in the literature since it vanishes due to the action of the delta function.
With this extra term the Green's function does not satisfy the source-free wave
equation (in the region outside of the source). We show that this term
corresponds to a charge imprinted on the light cone shell. Unlike the vector
field charge, a moving scalar field charge is not Lorentz invariant and is
contracted by the relativistic $\sqrt{1-v^2}$ factor. If a scalar charge is
moving at the speed of light, it appears to be zero in the static (with respect
to the original physical charge) observer's frame. However, the field it
sources is not entirely on the light cone. Thus, it is likely that this hidden
charge sources the mysterious tail in odd dimensions.
| [
"hep-th",
"gr-qc",
"hep-ph"
] | hep-th | gr-qc | High Energy Physics - Theory;General Relativity and Quantum Cosmology;High Energy Physics - Phenomenology | 3,328High Energy Physics - Theory;General Relativity and Quantum Cosmology;High Energy Physics - Phenomenology
|
1102.5599 | This paper concerns the consensus of discrete-time multi-agent systems with
linear or linearized dynamics. An observer-type protocol based on the relative
outputs of neighboring agents is proposed. The consensus of such a multi-agent
system with a directed communication topology can be cast into the stability of
a set of matrices with the same low dimension as that of a single agent. The
notion of discrete-time consensus region is then introduced and analyzed. For
neurally stable agents, it is shown that there exists an observer-type protocol
having a bounded consensus region in the form of an open unit disk, provided
that each agent is stabilizable and detectable. An algorithm is further
presented to construct a protocol to achieve consensus with respect to all the
communication topologies containing a spanning tree. Moreover, for the case
where the agents have no poles outside the unit circle,an algorithm is proposed
to construct a protocol having an origin-centered disk of radius $\delta$
($0<\delta<1$) as its consensus region, where $\delta$ has to further satisfy a
constraint related to the unstable eigenvalues of a single agent for the case
where each agent has a least one eigenvalue outside the unit circle. Finally,
the consensus algorithms are applied to solve formation control problems of
multi-agent systems.
| [
"cs.SY",
"math.OC"
] | cs.SY | math.OC | Systems and Control;Optimization and Control | 7,207Systems and Control;Optimization and Control
|
1508.01977 | We study the mixing time of the Dikin walk in a polytope - a random walk
based on the log-barrier from the interior point method literature. This walk,
and a close variant, were studied by Narayanan (2016) and Kannan-Narayanan
(2012). Bounds on its mixing time are important for algorithms for sampling and
optimization over polytopes. Here, we provide a simple proof of their result
that this random walk mixes in time O(mn) for an n-dimensional polytope
described using m inequalities.
| [
"cs.DS",
"math.OC"
] | cs.DS | math.OC | Data Structures and Algorithms;Optimization and Control | 1,966Data Structures and Algorithms;Optimization and Control
|
1304.3844 | This is the Proceedings of the Fourteenth Conference on Uncertainty in
Artificial Intelligence, which was held in Madison, WI, July 24-26, 1998
| [
"cs.AI"
] | cs.AI | Artificial Intelligence | 361Artificial Intelligence
|
|
quant-ph/0006006 | Any method for estimating the ensemble average of arbitrary operator
(observables or not, including the density matrix) relates the quantity of
interest to a complete set of observables, i.e. a quorum}. This corresponds to
an expansion on an irreducible set of operators in the Liouville space. We give
two general characterizations of these sets. All the known unbiased
reconstruction techniques, i.e. ``quantum tomographies'', can be described in
this framework. New operatorial resolutions are given that can be used to
implement novel reconstruction schemes.
| [
"quant-ph"
] | quant-ph | Quantum Physics | 5,985Quantum Physics
|
|
1405.3670 | The adsorption structure of the molecular switch azobenzene on Ag(111) is
investigated by a combination of normal incidence x-ray standing waves and
dispersion-corrected density functional theory. The inclusion of non-local
collective substrate response (screening) in the dispersion correction improves
the description of dense monolayers of azobenzene, which exhibit a substantial
torsion of the molecule. Nevertheless, for a quantitative agreement with
experiment explicit consideration of the effect of vibrational mode
anharmonicity on the adsorption geometry is crucial.
| [
"cond-mat.mtrl-sci",
"cond-mat.mes-hall",
"physics.chem-ph"
] | cond-mat.mtrl-sci | cond-mat.mes-hall | Materials Science;Mesoscale and Nanoscale Physics;Chemical Physics | 4,335Materials Science;Mesoscale and Nanoscale Physics;Chemical Physics
|
1112.2160 | Purpose: This paper aims at assessing the effect of (1) the statical
admissibility of the recovered solution; (2) the ability of the recovered
solution to represent the singular solution; on the accuracy, local and global
effectivity of recovery-based error estimators for enriched finite element
methods (e.g. the extended finite element method, XFEM).
Design/methodology/approach: We study the performance of two recovery
techniques. The first is a recently developed superconvergent patch recovery
procedure with equilibration and enrichment (SPR-CX). The second is known as
the extended moving least squares recovery (XMLS), which enriches the recovered
solutions but does not enforce equilibrium constraints. Both are extended
recovery techniques as the polynomial basis used in the recovery process is
enriched with singular terms for a better description of the singular nature of
the solution. Findings: Numerical results comparing the convergence and the
effectivity index of both techniques with those obtained without the enrichment
enhancement clearly show the need for the use of extended recovery techniques
in Zienkiewicz-Zhu type error estimators for this class of problems. The
results also reveal significant improvements in the effectivities yielded by
statically admissible recovered solutions. Originality/value: This work shows
that both extended recovery procedures and statical admissibility are key to an
accurate assessment of the quality of enriched finite element approximations.
| [
"physics.comp-ph",
"cs.NA"
] | physics.comp-ph | cs.NA | Computational Physics;Numerical Analysis | 1,430Computational Physics;Numerical Analysis
|
astro-ph/0512091 | This paper presents a consistent description of the formation and the
subsequent evolution of gaseous planets, with special attention to
short-period, low-mass hot-Neptune planets characteristic of $\mu$ Ara-like
systems. We show that core accretion including migration and disk evolution and
subsequent evolution taking into account irradiation and evaporation provide a
viable formation mechanism for this type of strongly irradiated light planets.
At an orbital distance $a \simeq$ 0.1 AU, this revised core accretion model
leads to the formation of planets with total masses ranging from $\sim$ 14
$\mearth$ (0.044 $\mjup$) to $\sim$ 400 $\mearth$ (1.25 $\mjup$). The newly
born planets have a dense core of $\sim$ 6 $\mearth$, independent of the total
mass, and heavy element enrichments in the envelope, $M_{\rm Z,env}/M_{\rm env}
$, varying from 10% to 80% from the largest to the smallest planets. We examine
the dependence of the evolution of the born planet on the evaporation rate due
to the incident XUV stellar flux. In order to reach a $\mu$ Ara-like mass
($\sim$ 14 $\mearth$) after $\sim $ 1 Gyr, the initial planet mass must range
from 166 $\mearth$ ($\sim$ 0.52 $\mjup$) to about 20 $\mearth$, for evaporation
rates varying by 2 orders of magnitude, corresponding to 90% to 20% mass loss
during evolution. The presence of a core and heavy elements in the envelope
affects appreciably the structure and the evolution of the planet and yields
$\sim 8%-9%$ difference in radius compared to coreless objects of solar
composition for Saturn-mass planets. These combinations of evaporation rates
and internal compositions translate into different detection probabilities, and
thus different statistical distributions for hot-Neptunes and hot-Jupiters.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
astro-ph/0304041 | In the current paper, we further develop the model for the migration of
planets introduced in Del Popolo et al. (2001) and extended to time-dependent
accretion discs in Del Popolo and Eksi (2002). We use a method developed by
Stepinski and Valageas (1996, 1997), that is able to simultaneously follow the
evolution of gas and solid particles for up to $10^7 {\rm yr}$. The disc model
is coupled to the migration model introduced in Del Popolo et al. (2001) in
order to obtain the migration rate of the planet in the planetesimal disc. We
find that in the case of discs having total mass of $10^{-3}-0.1 M_{\odot}$,
and $0.1<\alpha<0.0001$, planets can migrate inward a large distance while if
$M<10^{-3} M_{\odot}$ the planets remain almost in their initial position for
$0.1<\alpha<0.01$ and only in the case $\alpha<0.001$ the planets move to a
minimum value of orbital radius of $\simeq 2 {\rm AU}$. The model gives a good
description of the observed distribution of planets in the period range 0-20
days.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
gr-qc/9907062 | A method is presented for imputing a topology for any chronological set,
i.e., a set with a chronology relation, such as a spacetime or a spacetime with
some sort of boundary. This topology is shown to have several good properties,
such as replicating the manifold topology for a spacetime and replicating the
expected topology for some simple examples of spacetime-with-boundary; it also
allows for a complete categorical characterization, in topological categories,
of the Future Causal Boundary construction of Geroch, Kronheimer, and Penrose,
showing that construction to have a universal property for future-completing
chronological sets with spacelike boundaries. Rigidity results are given for
any reasonable future completion of a spacetime, in terms of the GKP boundary:
In the imputed topology, any such boundary must be homeomorphic to the GKP
boundary (if all points have indecomposable pasts) or to a topological quotient
of a closely related boundary (if boundaries are spacelike). A large class of
warped-product-type spacetimes with spacelike boundaries is examined,
calculating the GKP and other possible boundaries, and showing that the imputed
topology gives expected results; included among these are the Schwarzschild
singularity and those Robertson-Walker singularities which are spacelike.
| [
"gr-qc"
] | gr-qc | General Relativity and Quantum Cosmology | 2,674General Relativity and Quantum Cosmology
|
|
0805.2582 | We use a Jastrow-Slater wave function with an elliptical Fermi sea to
describe the nematic state of the two-dimensional electron gas in a magnetic
field and the Monte Carlo method to calculate a variational energy upper bound.
These energy upper bounds are compared with other upper bounds describing
stripe-ordered ground states which are obtained from optimized Hartree-Fock
calculations and with those which correspond to an isotropic ground state. Our
findings support the conclusions drawn in our previous study where the
Fermi-hypernetted chain approximation was used instead of the Monte Carlo
method. Namely, the nematic state becomes energetically favorable relative to
the stripe-ordered Wigner crystal phase for the second excited Landau level and
below a critical value of the layer ``thickness'' parameter which is very close
to its value in the actual materials.
| [
"cond-mat.mes-hall"
] | cond-mat.mes-hall | Mesoscale and Nanoscale Physics | 4,450Mesoscale and Nanoscale Physics
|