cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The SLUGGS Survey: Breaking degeneracies between dark matter, anisotropy and the IMF using globular cluster subpopulations in the giant elliptical NGC 5846
Creators: name: Napolitano, Nicola R.
name: Pota, Vincenzo
name: Romanowsky, Aaron J.
name: Forbes, Duncan A.
name: Brodie, Jean P.
name: Foster, Caroline
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study the mass and anisotropy distribution of the giant elliptical galaxy NGC 5846 using stars, as well as the red and blue globular cluster (GC) subpopulations. We break degeneracies in the dynamical models by taking advantage of the different phase space distributions of the two GC subpopulations to unambiguously constrain the mass of the galaxy and the anisotropy of the GC system. Red GCs show the same spatial distribution and behaviour as the starlight, whereas blue GCs have a shallower density profile, a larger velocity dispersion and a lower kurtosis, all of which suggest a different orbital distribution. We use a dispersion-kurtosis Jeans analysis and find that the solutions of separate analyses for the two GC subpopulations overlap in the halo parameter space. The solution converges on a massive dark matter halo, consistent with expectations from $Λ$CDM and WMAP7 cosmology in terms of virial mass ($\log M_{DM} \sim13.3 M_{sun}$) and concentration ($c_{vir}\sim8$). This is the first such analysis that solves the dynamics of the different GC subpopulations in a self-consistent manner. Our method improves the uncertainties on the halo parameter determination by a factor of two and opens new avenues for the use of elliptical galaxy dynamics as tests of predictions from cosmological simulations. The implied stellar mass-to-light ratio derived from the dynamical modelling is fully consistent with a Salpeter initial mass function (IMF) and rules out a bottom light IMF. The different GC subpopulations show markedly distinct orbital distributions at large radii, with red GCs having an anisotropy parameter $β\sim0.4$ outside $\sim3R_e$, and the blue GCs having $β\sim0.15$ at the same radii, while centrally ($\sim1R_e$) they are both isotropic. We discuss the implications of our findings within the two-phase formation scenario for early-type galaxies.
description: 16 pages, 8 figures. Accepted for publication on MNRAS
Reversing the Pump-Dependence of a Laser at an Exceptional Point
Creators: name: Brandstetter, M.
name: Liertzer, M.
name: Deutsch, C.
name: Klang, P.
name: Schöberl, J.
name: Türeci, H. E.
name: Strasser, G.
name: Unterrainer, K.
name: Rotter, S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: When two resonant modes in a system with gain or loss coalesce in both their resonance position and their width, a so-called "Exceptional Point" occurs which acts as a source of non-trivial physics in a diverse range of systems. Lasers provide a natural setting to study such "non-Hermitian degeneracies", since they feature resonant modes and a gain material as their basic constituents. Here we show that Exceptional Points can be conveniently induced in a photonic molecule laser by a suitable variation of the applied pump. Using a pair of coupled micro-disk quantum cascade lasers, we demonstrate that in the vicinity of these Exceptional Points the laser shows a characteristic reversal of its pump-dependence, including a strongly decreasing intensity of the emitted laser light for increasing pump power. This result establishes photonic molecule lasers as promising tools for exploring many further fascinating aspects of Exceptional Points, like a strong line-width enhancement and the coherent perfect absorption of light in their vicinity as well as non-trivial mode-switching and the accumulation of a geometric phase when encircling an Exceptional Point parametrically.
description: 19 pages, 7 figures, submitted version including supplementary information
Observational tests of the picture of disk accretion
Creators: name: Maccarone, Thomas J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this chapter, I present a summary of observational tests of the basic picture of disk accretion. An emphasis is placed on tests relevant to black holes, but many of the fundamental results are drawn from studies of other classes of systems. Evidence is discussed for the basic structures of accretion flows. The cases of systems with and without accretion disks are discussed, as is the evidence that disks actually form. Also discussed are the hot spots where accretion streams impact the disks, and the boundary layers in the inner parts of systems where the accretors are not black holes. The nature of slow, large amplitude variability is discussed. It is shown that some of the key predictions of the classical thermal-viscous ionization instability model for producing outbursts are in excellent agreement with observational results. It is also show that there are systems whose outbursts are extremely difficult to explain without invoking variations in the rate of mass transfer from the donor star into the outer accretion disk, or tidally induced variations in the mass transfer rates. Finally, I briefly discuss recent quasar microlensing measurements which give truly independent constraints on the inner accretion geometry around black holes.
description: 21 pages, 3 figures, accepted for publication in ISSI book on black holes in Space Science Reviews
title: Inter Alia
Creators: name: Leise, Richard
Publisher: name: Old Dominion University Libraries
Year: 2021

description: In Woody Allen’s Midnight in Paris, a fictional Gertrude Stein delivers some wonderful advice to an overwhelmed novelist, stating, “The artist’s job isn’t to succumb to despair, but to find an antidote for the emptiness of existence.” This has become a personal mantra. We are taught that Art—which, here, is to say the novel, or a collection of short stories—is the barrier dividing people from us. The stories informing Inter Alia are direct attempts to close this divide, and, using characterization, along with a handful of other literary elements and techniques, reflects my quest to find an antidote for the emptiness of existence.
Selling a Single Item with Negative Externalities
Creators: name: Chattopadhyay, Tithi
name: Feamster, Nick
name: Ferreira, Matheus V. X.
name: Huang, Danny Yuxing
name: Weinberg, S. Matthew
Publisher: name: arXiv
Year: 2019
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: Cryptography and Security (cs.CR)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: We consider the problem of regulating products with negative externalities to a third party that is neither the buyer nor the seller, but where both the buyer and seller can take steps to mitigate the externality. The motivating example to have in mind is the sale of Internet-of-Things (IoT) devices, many of which have historically been compromised for DDoS attacks that disrupted Internet-wide services such as Twitter. Neither the buyer (i.e., consumers) nor seller (i.e., IoT manufacturers) was known to suffer from the attack, but both have the power to expend effort to secure their devices. We consider a regulator who regulates payments (via fines if the device is compromised, or market prices directly), or the product directly via mandatory security requirements. Both regulations come at a cost---implementing security requirements increases production costs, and the existence of fines decreases consumers' values---thereby reducing the seller's profits. The focus of this paper is to understand the \emph{efficiency} of various regulatory policies. That is, policy A is more efficient than policy B if A more successfully minimizes negatives externalities, while both A and B reduce seller's profits equally. We develop a simple model to capture the impact of regulatory policies on a buyer's behavior. {In this model, we show that for \textit{homogeneous} markets---where the buyer's ability to follow security practices is always high or always low---the optimal (externality-minimizing for a given profit constraint) regulatory policy need regulate \emph{only} payments \emph{or} production.} In arbitrary markets, by contrast, we show that while the optimal policy may require regulating both aspects, there is always an approximately optimal policy which regulates just one.
Non-standard top substructure
Creators: name: Englert, Christoph
name: Goncalves, Dorival
name: Spannowsky, Michael
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The top quark, being the heaviest particle of the Standard Model, is a prime candidate of where physics beyond the SM might currently hide before our eyes. There are many natural extensions of the SM that rely on top compositeness, and the top quark could follow the paradigm of revealing a substructure when it is probed at high enough momentum transfers. Observing high $p_T$ top final states naturally drives us towards boosted hadronic analyses that can be tackled efficiently with jet substructure techniques. In this paper we analyse the prospects of constraining exemplary non-standard QCD top interactions in this kinematical regime. We correctly include QCD modifications to additional gluon emission off the boosted top quark and keep track of the modified top tagging efficiencies. We conclude that non-standard top QCD interactions can be formidably constrained at the LHC 14 TeV. Experimental systematic uncertainties are a major obstacle of the described measurement. Unless significantly improved for the 14 TeV run, they will saturate the direct sensitivity to non-resonant BSM top physics at luminosities of around 100/fb.
description: 9 pages, 7 figures
Transfer Learning for Hate Speech Detection in Social Media
Creators: name: Yuan, Lanqin
name: Wang, Tianyu
name: Ferraro, Gabriela
name: Suominen, Hanna
name: Rizoiu, Marian-Andrei
Publisher: name: arXiv
Year: 2019
Subjects: subject: Social and Information Networks (cs.SI)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Today, the internet is an integral part of our daily lives, enabling people to be more connected than ever before. However, this greater connectivity and access to information increase exposure to harmful content such as cyber-bullying and cyber-hatred. Models based on machine learning and natural language offer a way to make online platforms safer by identifying hate speech in web text autonomously. However, the main difficulty is annotating a sufficiently large number of examples to train these models. This paper uses a transfer learning technique to leverage two independent datasets jointly and builds a single representation of hate speech. We build an interpretable two-dimensional visualization tool of the constructed hate speech representation -- dubbed the Map of Hate -- in which multiple datasets can be projected and comparatively analyzed. The hateful content is annotated differently across the two datasets (racist and sexist in one dataset, hateful and offensive in another). However, the common representation successfully projects the harmless class of both datasets into the same space and can be used to uncover labeling errors (false positives). We also show that the joint representation boosts prediction performances when only a limited amount of supervision is available. These methods and insights hold the potential for safer social media and reduce the need to expose human moderators and annotators to distressing online messaging.
Examples of Enhanced Quantization: Bosons, Fermions, and Anyons
Creators: name: Adorno, T. C.
name: Klauder, J. R
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Enhanced quantization offers a different classical/quantum connection than that of canonical quantization in which $\hbar >0$ throughout. This result arises when the only allowed Hilbert space vectors allowed in the quantum action functional are coherent states, which leads to the classical action functional augmented by additional terms of order $\hbar$. Canonical coherent states are defined by unitary transformations of a fixed, fiducial vector. While Gaussian vectors are commonly used as fiducial vectors, they cannot be used for all systems. We focus on choosing fiducial vectors for several systems including bosons, fermions, and anyons.
Anisotropy of acoustooptic figure of merit in optically isotropic media
Creators: name: Mys, Oksana
name: Kostyrko, Myroslav
name: Smyk, Mykola
name: Krupych, Oleh
name: Vlokh, Rostyslav
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We suggest a new approach for analyzing spatial anisotropy of acoustooptic figure of merit (AOFM). The relations for the effective elastooptic coefficients and the AOFM are derived for all possible types of acoustooptic (AO) interactions in optically isotropic media, including non-solid-state and solid-state amorphous media, and crystals belonging to the cubic system. Our approach allows for finding the optimal geometries of AO interactions characterized by the highest AOFM for a given material. The analysis is carried out on the examples of cubic KBr and KAl(SO4)2x12H2O crystals which represent different subgroups of the cubic symmetry class.
description: 10 pages, 15 figures
Competing phases and critical behavior in three coupled spinless Luttinger liquids
Creators: name: Kundu, S.
name: Tripathi, V.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study electronic phase competition in a system of three coupled spinless Luttinger liquids using abelian bosonization, together with a perturbative renormalization group (RG) analysis. The scaling procedure generates off-diagonal contributions to the phase stiffness matrix, which require both rescaling as well as large rotations of the fields. These rotations, generally non-abelian in nature, are important for correctly obtaining the dominant electronic orders and critical behavior in different parameter regimes. They generate a coupling between different interaction channels even at the tree-level order in the coupling constant scaling equations. We study competing phases in this system, taking into account the aforementioned rotations, and determine its critical behavior in a variety of interaction parameter regimes where perturbative RG is possible. The phase boundaries are found to be of the Berezinskii-Kosterlitz-Thouless (BKT) type, and we specify the parameter regimes where valley-symmetry breaking, chiral orders, and restoration of $C_{3}$ symmetry may be observed. We discuss experimental systems where our approach and findings may be relevant.
description: 14 pages, 6 figures; added text, modified equations, shifted figure from Appendix to main text, replaced 3 figures
Spatially Resolving the Very High Energy emission from MGRO J2019+37 with VERITAS
Creators: name: VERITAS Collaboration
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present very high energy (VHE) imaging of MGRO J2019+37 obtained with the VERITAS observatory. The bright extended ($\sim2^{\circ}$) unidentified Milagro source is located towards the rich star formation region Cygnus-X. MGRO J2019+37 is resolved into two VERITAS sources. The faint point-like source VER J2016+371 overlaps CTB 87, a filled-center remnant (SNR) with no evidence of a supernova remnant shell at the present time. Its spectrum is well fit in the $0.65 - 10$ TeV energy range by a power-law model with photon index $2.3\pm0.4$. VER J2019+368 is a bright extended ($\sim1^{\circ}$) source, that likely accounts for the bulk of the Milagro emission and is notably coincident with PSR J2021+3651 and the star formation region Sh 2-104. Its spectrum in the range $1-30$ TeV is well fit with a power-law model of photon index $1.75\pm0.3$, among the hardest values measured in the VHE band, comparable to that observed near Vela-X. We explore the unusual spectrum and morphology in the radio and X-ray bands to constrain possible emission mechanisms for this source.
description: 9 pages, 8 figures, accepted for publication in the Astrophysical Journal
Adventures in Supersingularland
Creators: name: Arpin, Sarah
name: Camacho-Navarro, Catalina
name: Lauter, Kristin
name: Lim, Joelle
name: Nelson, Kristina
name: Scholl, Travis
name: Sotáková, Jana
Publisher: name: arXiv
Year: 2019
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: In this paper, we study isogeny graphs of supersingular elliptic curves. Supersingular isogeny graphs were introduced as a hard problem into cryptography by Charles, Goren, and Lauter for the construction of cryptographic hash functions [CGL06]. These are large expander graphs, and the hard problem is to find an efficient algorithm for routing, or path-finding, between two vertices of the graph. We consider four aspects of supersingular isogeny graphs, study each thoroughly and, where appropriate, discuss how they relate to one another. First, we consider two related graphs that help us understand the structure: the `spine' $\mathcal{S}$, which is the subgraph of $\mathcal{G}_\ell(\overline{\mathbb{F}_p})$ given by the $j$-invariants in $\mathbb{F}_p$, and the graph $\mathcal{G}_\ell(\mathbb{F}_p)$, in which both curves and isogenies must be defined over $\mathbb{F}_p$. We show how to pass from the latter to the former. The graph $\mathcal{S}$ is relevant for cryptanalysis because routing between vertices in $\mathbb{F}_p$ is easier than in the full isogeny graph. The $\mathbb{F}_p$-vertices are typically assumed to be randomly distributed in the graph, which is far from true. We provide an analysis of the distances of connected components of $\mathcal{S}$. Next, we study the involution on $\mathcal{G}_\ell(\overline{\mathbb{F}_p})$ that is given by the Frobenius of $\mathbb{F}_p$ and give heuristics on how often shortest paths between two conjugate $j$-invariants are preserved by this involution (mirror paths). We also study the related question of what proportion of conjugate $j$-invariants are $\ell$-isogenous for $\ell = 2,3$. We conclude with experimental data on the diameters of supersingular isogeny graphs when $\ell = 2$ and compare this with previous results on diameters of LPS graphs and random Ramanujan graphs.
description: 46 pages. Comments welcome
MATLAB code to determine rate of torque development for mouse knee extension
Creators: name: Fry, Christopher
Publisher: name: Zenodo
Year: 2023

description: MATLAB code is provided in two pdf files to generate rate of torque development (RTD) from peak isometric tetanic torque in mice performing knee extension. RTD can be assessed with this code in both raw and peak torque-normalized values.
description: For RTD calculation, the linear torque-time slope was calculated with a least squares regression fit during twentieth to eightieth percentile of peak tetanic torque. RTD values were also measured controlling for peak tetanic torque. The time torque curve was normalized to the peak value, and the linear torque-time slope was calculated with a least squares regression fit during twentieth to eightieth percentile of peak tetanic torque to reflect peak torque normalized RTD.
Precise parameters for both white dwarfs in the eclipsing binary CSS 41177
Creators: name: Bours, M. C. P.
name: Marsh, T. R.
name: Parsons, S. G.
name: Copperwheat, C. M.
name: Dhillon, V. S.
name: Littlefair, S. P.
name: Gänsicke, B. T.
name: Gianninas, A.
name: Tremblay, P. -E.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present ULTRACAM photometry and X-Shooter spectroscopy of the eclipsing double white dwarf binary CSS 41177, the only such system that is also a double-lined spectroscopic binary. Combined modelling of the light curves and radial velocities yield masses and radii for both white dwarfs without the need to assume mass-radius relations. We find that the primary white dwarf has a mass of M1 = 0.38(2) Msun and a radius of R1 = 0.0222(4) Rsun. The secondary white dwarf's mass and radius are M2 = 0.32(1) Msun and R2 = 0.0207(4) Rsun, and its temperature and surface gravity (T2 = 11678(313) K, log(g2) = 7.32(2)) put it close to the white dwarf instability strip. However, we find no evidence for pulsations to roughly 0.5% relative amplitude. Both masses and radii are consistent with helium white dwarf models with thin hydrogen envelopes of 0.0001 Mstar. The two stars will merge in 1.14 Gyr due to angular momentum loss via gravitational wave emission.
description: Accepted for publication in MNRAS
Rinaldi J. (dir.). Introdução à leitura da Bíblia. T. III. Ed. Livraria Tavares Martins. Vol. de 730 ps. 175x243. Porto 1970
Creators: name: Rodrigues, António Ferreira
Publisher: name: Theologica
Year: 1971

description: Theologica, v. 6 n. 3 (1971)
Thermodynamics and reentrant phase transition for logarithmic nonlinear charged black holes in massive gravity
Creators: name: Chaloshtary, S. Rajaee
name: Zangeneh, M. Kord
name: Hajkhalili, S.
name: Sheykhi, A.
name: Zebarjad, S. M.
Publisher: name: arXiv
Year: 2019
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate a new class of $(n+1)$-dimensional topological black hole solutions in the context of massive gravity and in the presence of logarithmic nonlinear electrodynamics. Exploring higher dimensional solutions in massive gravity coupled to nonlinear electrodynamics is motivated by holographic hypothesis as well as string theory. We first construct exact solutions of the field equations and then explore the behavior of the metric functions for different values of the model parameters. We observe that our black holes admit the multi-horizons caused by a quantum effect called anti-evaporation. Next, by calculating the conserved and thermodynamic quantities, we obtain a generalized Smarr formula. We find that the first law of black holes thermodynamics is satisfied on the black hole horizon. We study thermal stability of the obtained solutions in both canonical and grand canonical ensembles. We reveal that depending on the model parameters, our solutions exhibit a rich variety of phase structures. Finally, we explore, for the first time without extending thermodynamics phase space, the critical behavior and reentrant phase transition for black hole solutions in massive gravity theory. We realize that there is a zeroth order phase transition for a specified range of charge value and the system experiences a large/small/large reentrant phase transition due to the presence of nonlinear electrodynamics.
description: 14 pages (one column), 12 captioned figures
Hardy spaces meet harmonic weights
Creators: name: Preisner, Marcin
name: Sikora, Adam
name: Yan, Lixin
Publisher: name: arXiv
Year: 2019
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 42B30, 42B35, 47B38, 31A05

description: We investigate the Hardy space $H^1_L$ associated with a self-adjoint operator $L$ defined in a general setting in [S. Hofmann, et. al., Hardy spaces associated to non-negative self-adjoint operators satisfying Davies-Gaffney estimates, Mem. Amer. Math. Soc. 214 (2011), no. 1007, vi+78.]. We assume that there exists an $L$-harmonic non-negative function $h$ such that the semigroup $\exp(-tL)$, after applying the Doob transform related to $h$, satisfies the upper and lower Gaussian estimates. Under this assumption we describe an illuminating characterisation of the Hardy space $H^1_L$ in terms of a simple atomic decomposition associated with the $L$-harmonic function $h$. Our approach also yields a natural characterisation of the $BMO$-type space corresponding to the operator $L$ and dual to $H^1_L$ in the same circumstances. The applications include surprisingly wide range of operators, such as: Laplace operators with Dirichlet boundary conditions on some domains in $\mathbb{R}^d$, Schrödinger operators with certain potentials, and Bessel operators.
Confinement and Mayer cluster expansions
Creators: name: Bourgine, Jean-Emile
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In these notes, we study a class of grand-canonical partition functions with a kernel depending on a small parameter $ε$. This class is directly relevant to Nekrasov partition functions of $\mathcal{N}=2$ SUSY gauge theories on the 4d $Ω$-background, for which $ε$ is identified with one of the equivariant deformation parameter. In the Nekrasov-Shatashvili limit $ε\to0$, we show that the free energy is given by an on-shell effective action. The equations of motion take the form of a TBA equation. The free energy is identified with the Yang-Yang functional of the corresponding system of Bethe roots. We further study the associated canonical model that takes the form of a generalized matrix model. Confinement of the eigenvalues by the short-range potential is observed. In the limit where this confining potential becomes weak, the collective field theory formulation is recovered. Finally, we discuss the connection with the alternative expression of instanton partition functions as sums over Young tableaux.
description: 24 pages, 4 figures
Dirac-Coulomb operators with general charge distribution. II. The lowest eigenvalue
Creators: name: Esteban, Maria J.
name: Lewin, Mathieu
name: Séré, Éric
Publisher: name: arXiv
Year: 2020
Subjects: subject: Spectral Theory (math.SP)
subject: Mathematical Physics (math-ph)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Consider the Coulomb potential $-μ\ast|x|^{-1}$ generated by a non-negative finite measure $μ$. It is well known that the lowest eigenvalue of the corresponding Schrödinger operator $-Δ/2-μ\ast|x|^{-1}$ is minimized, at fixed mass $μ(\mathbb{R}^3)=ν$, when $μ$ is proportional to a delta. In this paper we investigate the conjecture that the same holds for the Dirac operator $-iα\cdot\nabla+β-μ\ast|x|^{-1}$. In a previous work on the subject we proved that this operator is self-adjoint when $μ$ has no atom of mass larger than or equal to 1, and that its eigenvalues are given by min-max formulas. Here we consider the critical mass $ν_1$, below which the lowest eigenvalue does not dive into the lower continuum spectrum for all $μ\geq0$ with $μ(\mathbb{R}^3)<ν_1$. We first show that $ν_1$ is related to the best constant in a new scaling-invariant Hardy-type inequality. Our main result is that for all $0\leqν<ν_1$, there exists an optimal measure $μ\geq0$ giving the lowest possible eigenvalue at fixed mass $μ(\mathbb{R}^3)=ν$, which concentrates on a compact set of Lebesgue measure zero. The last property is shown using a new unique continuation principle for Dirac operators. The existence proof is based on the concentration-compactness principle.
description: Final version to appear in Proc. London Math. Soc
A background simulation method for cosmogenic nuclides inside HPGe detectors for rare event experiments
Creators: name: Su, Jian
name: Zeng, Zhi
name: Ma, Hao
name: Yue, Qian
name: Cheng, Jianping
name: Li, Jin
Publisher: name: arXiv
Year: 2013
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Cosmogenic nuclides inside germanium detectors contribute background noise spectra quite different from ordinary external sources. We propose and discuss a nuclide decay and level transition model based on graph theory to understand the background contribution of the decay of cosmogenic nuclides inside a germanium crystal. In this work, not only was the level transition process, but the detector response time was also taken into consideration to decide whether or not to apply coincidence summing-up. We simulated the background spectrum of the internal cosmogenic nuclides in a germanium detector, and found some unique phenomena caused by the coincidence summing-up effect in the simulated spectrum. Thus, the background spectrum of each cosmogenic nuclide can be quantitatively obtained.
description: 16 pages, 10 figures
Some notes about distribution frame multipliers
Creators: name: Corso, Rosario
name: Tschinke, Francesco
Publisher: name: arXiv
Year: 2019
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 47A70, 42C15, 42C30

description: Inspired by a recent work about distribution frames, the definition of multiplier operator is extended in the rigged Hilbert spaces setting and a study of its main properties is carried on. In particular, conditions for the density of domain and boundedness are given. The case of Riesz distribution bases is examined in order to develop a symbolic calculus.
Signatures of superconducting and pseudogap phases in ultrafast transient reflectivity of Ca(Fe0.927Co0.073)2As2
Creators: name: Kumar, Sunil
name: Harnagea, L.
name: Wurmehl, S.
name: Buechner, B.
name: Sood, A. K.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We present femtosecond time-resolved pump-probe spectroscopic studies of a pseudogap (PG) along with the superconducting (SC) gap in an overdoped iron pnictide Ca(Fe0.927Co0.073)2As2. It is seen that the temperature evolution of the photoexcited quasiparticle (QP) relaxation dynamics, coherently excited A1g-symmetric optical phonon and two acoustic phonon dynamics behave anomalously in the vicinity of the superconducting transition temperature Tc. A continuous change in the sign of the experimentally measured transient differential reflectivity Delta_R/R signal at the zero time-delay between the pump and probe pulses at a temperature of ~200 K is inferred as an evidence of the emergence of the PG phase around that temperature. This behavior is independent of the pump photon energy and occurs for crystals without the spin density wave phase transition.
description: EPL (2014)
Credible, Truthful, and Two-Round (Optimal) Auctions via Cryptographic Commitments
Creators: name: Ferreira, Matheus V. X.
name: Weinberg, S. Matthew
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: Cryptography and Security (cs.CR)
subject: Theoretical Economics (econ.TH)
subject: FOS: Computer and information sciences
subject: FOS: Economics and business

description: We consider the sale of a single item to multiple buyers by a revenue-maximizing seller. Recent work of Akbarpour and Li formalizes \emph{credibility} as an auction desideratum, and prove that the only optimal, credible, strategyproof auction is the ascending price auction with reserves (Akbarpour and Li, 2019). In contrast, when buyers' valuations are MHR, we show that the mild additional assumption of a cryptographically secure commitment scheme suffices for a simple \emph{two-round} auction which is optimal, strategyproof, and credible (even when the number of bidders is only known by the auctioneer). We extend our analysis to the case when buyer valuations are $α$-strongly regular for any $α> 0$, up to arbitrary $\varepsilon$ in credibility. Interestingly, we also prove that this construction cannot be extended to regular distributions, nor can the $\varepsilon$ be removed with multiple bidders.
Fully coherent follow-up of continuous gravitational-wave candidates: an application to Einstein@Home results
Creators: name: Shaltev, Miroslav
name: Leaci, Paola
name: Papa, Maria Alessandra
name: Prix, Reinhard
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We characterize and present the details of the follow-up method used on the most significant outliers of the Hough Einstein@Home all-sky search for continuous gravitational waves arXiv:1207.7176. This follow-up method is based on the two-stage approach introduced in arXiv:1303.2471, consisting of a semicoherent refinement followed by a fully coherent zoom. We quantify the efficiency of the follow-up pipeline using simulated signals in Gaussian noise. This pipeline does not search beyond first-order frequency spindown, and therefore we also evaluate its robustness against second-order spindown. We present the details of the Hough Einstein@Home follow-up (arXiv:1207.7176) on three hardware-injected signals and on the 8 most significant outliers of unknown origin.
description: 8 pages, 3 figures, 3 tables
Safe Learning MPC with Limited Model Knowledge and Data
Creators: name: Kandel, Aaron
name: Moura, Scott J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: Optimization and Control (math.OC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics

description: This paper presents an end-to-end framework for safe learning-based control (LbC) using nonlinear stochastic MPC and distributionally robust optimization (DRO). This work is motivated by several open challenges in LbC literature. In particular, many control-theoretic LbC methods require subject matter expertise in order to translate their own safety guarantees, often manifested as preexisting data of safe trajectories or structural model knowledge. In this paper, we focus on LbC where the controller is applied directly to a system of which it has no or extremely limited direct experience, towards safety during \textit{tabula-rasa} or ``\textit{blank slate''} model-based learning and control as a challenging case for validation. This explores the boundary of the status-quo in control theory relating to requirements for subject matter expertise. We show under basic and limited assumptions on the underlying problem, we can translate probabilistic guarantees on feasibility to nonlinear systems using results in stochastic MPC and DRO literature whose relevance we formally extend in a mathematical analysis. We also present a coupled and intuitive formulation for persistence of excitation (PoE), and illustrate the connection between PoE and applicability of the proposed method. Our case studies of vehicle obstacle avoidance and safe extreme fast charging of lithium-ion batteries reveal powerful empirical results supporting the underlying DRO theory. Our method is widely applicable within the LbC domain to, for example, airborne wind energy systems, vehicle obstacle avoidance, and energy storage systems management. It is also applicable to quantifying uncertainty beyond the LbC case.
Orbits of bounded bijective operators and Gabor frames
Creators: name: Corso, Rosario
Publisher: name: arXiv
Year: 2020
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 42C15, 94A20

description: This paper is a contribution to frame theory. Frames in a Hilbert space are generalizations of orthonormal bases. In particular, Gabor frames of $L^2(\mathbb{R})$, which are made of translations and modulations of one or more windows, are often used in applications. More precisely, the paper deals with a question posed in the last years by Christensen and Hasannasab about the existence of overcomplete Gabor frames, with some ordering over $\mathbb{Z}$, which are orbits of bounded operators on $L^2(\mathbb{R})$. Two classes of overcomplete Gabor frames which cannot be ordered over $\mathbb{Z}$ and represented by orbits of operators in $GL(L^2(\mathbb{R}))$ are given. Some results about operator representation are stated in a general context for arbitrary frames, covering also certain wavelet frames.
description: 12 pages
The PdBI Arcsecond Whirlpool Survey (PAWS): Environmental Dependence of Giant Molecular Cloud Properties in M51
Creators: name: Colombo, Dario
name: Hughes, Annie
name: Schinnerer, Eva
name: Meidt, Sharon E.
name: Leroy, Adam K.
name: Pety, Jerome
name: Dobbs, Clare L.
name: Garcia-Burillo, Santiago
name: Dumas, Gaelle
name: Thompson, Todd A.
name: Schuster, Karl F.
name: Kramer, Carsten
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Using data from the PdBI Arcsecond Whirlpool Survey (PAWS), we have generated the largest extragalactic Giant Molecular Cloud (GMC) catalog to date, containing 1,507 individual objects. GMCs in the inner M51 disk account for only 54% of the total 12CO(1-0) luminosity of the survey, but on average they exhibit physical properties similar to Galactic GMCs. We do not find a strong correlation between the GMC size and velocity dispersion, and a simple virial analysis suggests that 30% of GMCs in M51 are unbound. We have analyzed the GMC properties within seven dynamically-motivated galactic environments, finding that GMCs in the spiral arms and in the central region are brighter and have higher velocity dispersions than inter-arm clouds. Globally, the GMC mass distribution does not follow a simple power law shape. Instead, we find that the shape of the mass distribution varies with galactic environment: the distribution is steeper in inter-arm region than in the spiral arms, and exhibits a sharp truncation at high masses for the nuclear bar region. We propose that the observed environmental variations in the GMC properties and mass distributions are a consequence of the combined action of large-scale dynamical processes and feedback from high mass star formation. We describe some challenges of using existing GMC identification techniques for decomposing the 12CO(1-0) emission in molecule-rich environments, such as M51's inner disk.
description: 73 pages, 18 figures, 14 tables, accepted for publication in ApJ
Genome-wide host-pathogen analyses reveal genetic interaction points in tuberculosis disease.
Creators: name: Phelan, Jody
name: Gomez-Gonzalez, Paula Josefina
name: Andreu, Nuria
name: Omae, Yosuke
name: Toyo-Oka, Licht
name: Yanai, Hideki
name: Miyahara, Reiko
name: Nedsuwan, Supalert
name: De Sessions, Paola Florez
name: Campino, Susana
name: Sallah, Neneh
name: Parkhill, Julian
name: Smittipat, Nat
name: Palittapongarnpim, Prasit
name: Mushiroda, Taisei
name: Kubo, Michiaki
name: Tokunaga, Katsushi
name: Mahasirimongkol, Surakameth
name: Hibberd, Martin L
name: Clark, Taane G
Publisher: name: Apollo - University of Cambridge Repository
Year: 2023
Subjects: Humans
Genome-Wide Association Study
Phylogeny
Tuberculosis
Mycobacterium tuberculosis
Genome
Host-Pathogen Interactions

description: The genetics underlying tuberculosis (TB) pathophysiology are poorly understood. Human genome-wide association studies have failed so far to reveal reproducible susceptibility loci, attributed in part to the influence of the underlying Mycobacterium tuberculosis (Mtb) bacterial genotype on the outcome of the infection. Several studies have found associations of human genetic polymorphisms with Mtb phylo-lineages, but studies analysing genome-genome interactions are needed. By implementing a phylogenetic tree-based Mtb-to-human analysis for 714 TB patients from Thailand, we identify eight putative genetic interaction points (P < 5 × 10-8) including human loci DAP and RIMS3, both linked to the IFNγ cytokine and host immune system, as well as FSTL5, previously associated with susceptibility to TB. Many of the corresponding Mtb markers are lineage specific. The genome-to-genome analysis reveals a complex interactome picture, supports host-pathogen adaptation and co-evolution in TB, and has potential applications to large-scale studies across many TB endemic populations matched for host-pathogen genomic diversity.
Universal filtered quantizations of nilpotent Slodowy slices
Creators: name: Ambrosio, Filippo
name: Carnovale, Giovanna
name: Esposito, Francesco
name: Topley, Lewis
Publisher: name: arXiv
Year: 2020
Subjects: subject: Representation Theory (math.RT)
subject: Algebraic Geometry (math.AG)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 14B07, 17B08

description: Every conic symplectic singularity admits a universal Poisson deformation and a universal filtered quantization, thanks to the work of Losev and Namikawa. We begin this paper by showing that every such variety admits a universal equivariant Poisson deformation and a universal equivariant quantization with respect to a reductive group acting on it by $\mathbb{C}^\times$-equivariant Poisson automorphisms. We go on to study these definitions in the context of nilpotent Slodowy slices. First we give a complete description of the cases in which the finite $W$-algebra is a universal filtered quantization of the slice, building on the work of Lehn--Namikawa--Sorger. This leads to a near-complete classification of the filtered quantizations of nilpotent Slodowy slices. The subregular slices in non-simply-laced Lie algebras are especially interesting: with some minor restrictions on Dynkin type we prove that the finite $W$-algebra is a universal equivariant quantization with respect to the Dynkin automorphisms coming from the unfolding of the Dynkin diagram. This can be seen as a non-commutative analogue of Slodowy's theorem. Finally we apply this result to give a presentation of the subregular finite $W$-algebra in type B as a quotient of a shifted Yangian.
description: 23 pages, v5: accepted for publication in the Journal of Noncommutative Geometry
Higgs Searches Beyond the Standard Model
Creators: name: Mankel, Rainer
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: While the existence of a Higgs boson with a mass near 125 GeV has been clearly established, the detailed structure of the entire Higgs sector is yet unclear. Besides the Standard Model interpretation, various possibilities for extended Higgs sectors are being considered. The minimal supersymmetric extension (MSSM) features two Higgs doublets resulting in five physical Higgs bosons, which are subject to direct searches. Alternatively, more generic Two-Higgs Doublet models (2HDM) are used for the interpretation of results. The Next-to-Minimal Supersymmetric Model (NMSSM) has a more complex Higgs sector with seven physical states. Also exotic Higgs bosons decaying to invisible final states are considered. This article summarizes recent findings based on results from collider experiments.
description: 13 pages, 11 figures; presented at Physics in Collision 2013
Driven colloidal suspensions in confinement and density functional theory: Microstructure and wall-slip
Creators: name: Aerov, Artem A.
name: Krüger, Matthias
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We theoretically investigate general properties of driven (sheared) colloidal suspensions in confinement, based on methods of classical density functional theory. In the absence of an exact closed (Smoluchowski-) equation for the one-particle density under shear, we formulate a set of general conditions for approximations, and show that a simple closure fulfills them. The exact microscopic stress tensor is identified. Exemplifying the situation near a wall (oriented parallel to the direction of shear), we note that the microscopic shear stress is not necessarily homogeneous. Formulating a second equation additional to the Smoluchowski equation, we achieve a homogeneous shear stress, and thereby compute the local flow velocity near the wall. This finally leads to a slip length of the complex fluid at the wall.
description: 11 pages, 8 figures
6d $\mathcal N=(1,0)$ anomalies on $S^1$ and F-theory implications
Creators: name: Corvilain, Pierre
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that the pure gauge anomalies of 6d $\mathcal N=(1,0)$ theories compactified on a circle are captured by field-dependent Chern-Simons terms appearing at one-loop in the 5d effective theories. These terms vanish if and only if anomalies are canceled. In order to obtain this result, it is crucial to integrate out the massive Kaluza-Klein modes in a way that preserves 6d Lorentz invariance; the often-used zeta-function regularization is not sufficient. Since such field-dependent Chern-Simons terms do not arise in the reduction of M-theory on a threefold, six-dimensional F-theory compactifications are automatically anomaly free, whenever the M/F-duality can be used. A perfect match is then found between the 5d $\mathcal N=1$ prepotentials of the classical M-theory reduction and one-loop circle compactification of an anomaly free theory. Finally, from this potential, we read off the quantum corrections to the gauge coupling functions.
description: 22 pages, 2 figures
Self-force via Green functions and worldline integration
Creators: name: Wardell, Barry
name: Galley, Chad R.
name: Zenginoglu, Anil
name: Casals, Marc
name: Dolan, Sam R.
name: Ottewill, Adrian C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A compact object moving in curved spacetime interacts with its own gravitational field. This leads to both dissipative and conservative corrections to the motion, which can be interpreted as a self-force acting on the object. The original formalism describing this self-force relied heavily on the Green function of the linear differential operator that governs gravitational perturbations. However, because the global calculation of Green functions in non-trivial black hole spacetimes has been an open problem until recently, alternative methods were established to calculate self-force effects using sophisticated regularization techniques that avoid the computation of the global Green function. We present a method for calculating the self-force that employs the global Green function and is therefore closely modeled after the original self-force expressions. Our quantitative method involves two stages: (i) numerical approximation of the retarded Green function in the background spacetime; (ii) evaluation of convolution integrals along the worldline of the object. This novel approach can be used along arbitrary worldlines, including those currently inaccessible to more established computational techniques. Furthermore, it yields geometrical insight into the contributions to self-interaction from curved geometry (back-scattering) and trapping of null geodesics. We demonstrate the method on the motion of a scalar charge in Schwarzschild spacetime. This toy model retains the physical history-dependence of the self-force but avoids gauge issues and allows us to focus on basic principles. We compute the self-field and self-force for many worldlines including accelerated circular orbits, eccentric orbits at the separatrix, and radial infall. This method, closely modeled after the original formalism, provides a promising complementary approach to the self-force problem.
description: 18 pages, 9 figures