cssi/SciSciGPT-SciSciNet huggingface dataset:
AN ANALYSIS OF THE SHAPES OF INTERSTELLAR EXTINCTION CURVES. VI. THE NEAR-IR EXTINCTION LAW

We combine new observations from the Hubble Space Telescope's Advanced Camera of Survey with existing data to investigate the wavelength dependence of near-IR (NIR) extinction. Previous studies suggest a power law form for NIR extinction, with a "universal" value of the exponent, although some recent observations indicate that significant sight line-to-sight line variability may exist. We show that a power-law model for the NIR extinction provides an excellent fit to most extinction curves, but that the value of the power, β, varies significantly from sight line to sight line. Therefore, it seems that a "universal NIR extinction law" is not possible. Instead, we find that as β decreases, R(V) ≡ A(V)/E(B – V) tends to increase, suggesting that NIR extinction curves which have been considered "peculiar" may, in fact, be typical for different R(V) values. We show that the power-law parameters can depend on the wavelength interval used to derive them, with the β increasing as longer wavelengths are included. This result implies that extrapolating power-law fits to determine R(V) is unreliable. To avoid this problem, we adopt a different functional form for NIR extinction. This new form mimics a power law whose exponent increases with wavelength, has only two free parameters, can fit all of our curves over a longer wavelength baseline and to higher precision, and produces R(V) values which are consistent with independent estimates and commonly used methods for estimating R(V). Furthermore, unlike the power-law model, it gives R(V)s that are independent of the wavelength interval used to derive them. It also suggests that the relation can estimate R(V) to ±0.12. Finally, we use model extinction curves to show that our extinction curves are in accord with theoretical expectations, and demonstrate how large samples of observational quantities can provide useful constraints on the grain properties.
COULOMB CORRELATIONS AND INSTABILITY OF SPINLESS FERMION GAS IN 1D AND 2D

We study the stability of the ordinary Landau Fermi liquid phase for interacting, spinless electrons. We require causality and demand that the Pauli principle be obeyed. We find a phase diagram determined by two parameters: the particle density and the interaction strength. We find that the homogeneous, constant density Fermi liquid phase of a spinless Fermion gas is never stable in 1D, but that it may have a restricted domain of stability in 2D.
Correlating spin transport and electrode magnetization in a graphene spin valve: Simultaneous magnetic microscopy and non-local measurements

Using simultaneous magnetic force microscopy and transport measurements of a graphene spin valve, we correlate the non-local spin signal with the magnetization of the device electrodes. The imaged magnetization states corroborate the influence of each electrode within a one-dimensional spin transport model and provide evidence linking domain wall pinning to additional features in the transport signal.
Optical modulation effects on nonlinear electron transport in graphene in terahertz frequency range

We describe very fast electron dynamics for a graphene nanoribbon driven by a control electromagnetic field in the terahertz frequency regime. The mobility as a function of bias field has been found to possess a large threshold value when entering a nonlinear transport regime. This value depends on the lattice temperature, electron density, impurity scattering strength, nanoribbon width and correlation length for the line-edge roughness. An enhanced electron mobility beyond this threshold has been observed, which is related to the initially-heated electrons in high energy states with a larger group velocity. However, this mobility enhancement quickly reaches a maximum governed by the Fermi velocity in graphene and the dramatically increased phonon scattering. Super-linear and sub-linear temperature dependences of the mobility are seen in the linear and nonlinear transport regimes, which is attributed separately to the results of sweeping electrons from the right Fermi edge to the left one through elastic ...
Syzygies and tensor product of modules

We give an application of the New Intersection Theorem and prove the following: let \(R\) be a local complete intersection ring of codimension \(c\) and let \(M\) and \(N\) be nonzero finitely generated \(R\)-modules. Assume \(n\) is a nonnegative integer and that the tensor product \(M\otimes _{R}N\) is an \((n+c)\)th syzygy of some finitely generated \(R\)-module. If \({{\mathrm{Tor}}}^{R}_{>0}(M,N)=0\), then both \(M\) and \(N\) are \(n\)th syzygies of some finitely generated \(R\)-modules.
Mini-Minimax Uncertainty Quantification for Emulators

Consider approximating a “black box” function $f$ by an emulator $\hat{f}$ based on $n$ noiseless observations of $f$. Let $w$ be a point in the domain of $f$. How big might the error $|\hat{f}(w) - f(w)|$ be? If $f$ could be arbitrarily rough, this error could be arbitrarily large: we need some constraint on $f$ besides the data. Suppose $f$ is Lipschitz with a known constant. We find a lower bound on the number of observations required to ensure that for the best emulator $\hat{f}$ based on the $n$ data, $|\hat{f}(w) - f(w)| \le \epsilon$. But in general, we will not know whether $f$ is Lipschitz, much less know its Lipschitz constant. Assume optimistically that $f$ is Lipschitz-continuous with the smallest constant consistent with the $n$ data. We find the maximum (over such regular $f$) of $|\hat{f}(w) - f(w)|$ for the best possible emulator $\hat{f}$; we call this the “mini-minimax uncertainty” at $w$. In reality, $f$ might not be Lipschitz or---if it is---it might not attain its Lipschitz constant o...
Flow Topology during Multiplexed Particle Manipulation Using a Stokes Trap

Understanding how small particles can be precisely manipulated using only fluid flow is critically important for enabling new studies in soft materials, colloidal science, and biophysics. This study characterizes the underlying flow topologies and performance of a Stokes trap, using multiplexed particle-trapping experiments and numerical simulations. Unexpectedly, the authors find that optimal control of two particles involves the occurrence of zero or one stagnation points--- not two distinct points. The results will facilitate studies of soft matter involving particle-particle interactions, such as controlled adhesion between vesicles and biological cells.
Parallel Tracking and Verifying

Visual object tracking has played a crucial role in computer vision with many applications. Being intensively studied in recent decades, visual tracking has witnessed great advances in either speed (e.g., with correlation filters) or accuracy (e.g., with deep features). Real-time and high accuracy tracking algorithms, nevertheless, remain scarce. In this paper, we study the problem from a new perspective and present a novel parallel tracking and verifying (PTAV) framework, by taking advantage of the ubiquity of multi-thread techniques and borrowing ideas from the success of parallel tracking and mapping in visual SLAM. The proposed PTAV framework typically consists of two components, a (base) tracker $\mathcal {T}$ and a verifier $\mathcal {V}$ , working in parallel on two separate threads. The tracker $\mathcal {T}$ aims at providing a super real-time tracking inference and is expected to perform well most of the time; by contrast, the verifier $\mathcal {V}$ validates the tracking results and corrects $\mathcal {T}$ when needed. The key innovation is that $\mathcal {V}$ does not work on every frame but only upon the requests from $\mathcal {T}$ ; on the other end, $\mathcal {T}$ may adjust the tracking according to the feedback from $\mathcal {V}$ . With such collaboration, PTAV enjoys both high efficiencies provided by $\mathcal {T}$ and strong discriminative power by $\mathcal {V}$ . Meanwhile, in order to adapt $\mathcal {V}$ to object appearance changes, we maintain a dynamic target template pool for adaptive verification, resulting in further improvement. In our extensive experiments on OTB2015, TC128, UAV20L, and VOT2016, PTAV achieves top tracking accuracy among all real-time trackers, and in fact, even outperforms many deep learning-based algorithms. Moreover, as a general framework, PTAV is very flexible with great potentials for future improvement and generalization.
Vacuum stability and symmetry breaking in left-right symmetric model

We derive analytic necessary and sufficient conditions for the vacuum stability of the left-right symmetric model by using the concepts of copositivity and gauge orbit spaces. We also derive the conditions sufficient for successful symmetry breaking and the existence of a correct vacuum. We then compare results obtained from the derived conditions with those from numerical minimization of the scalar potential. Finally, we discuss the renormalization group analysis of the scalar quartic couplings through an example study that satisfies vacuum stability, perturbativity, unitarity and experimental bounds on the physical scalar masses.
Towards Deeper Graph Neural Networks

Graph neural networks have shown significant success in the field of graph representation learning. Graph convolutions perform neighborhood aggregation and represent one of the most important graph operations. Nevertheless, one layer of these neighborhood aggregation methods only consider immediate neighbors, and the performance decreases when going deeper to enable larger receptive fields. Several recent studies attribute this performance deterioration to the over-smoothing issue, which states that repeated propagation makes node representations of different classes indistinguishable. In this work, we study this observation systematically and develop new insights towards deeper graph neural networks. First, we provide a systematical analysis on this issue and argue that the key factor compromising the performance significantly is the entanglement of representation transformation and propagation in current graph convolution operations. After decoupling these two operations, deeper graph neural networks can be used to learn graph node representations from larger receptive fields. We further provide a theoretical analysis of the above observation when building very deep models, which can serve as a rigorous and gentle description of the over-smoothing issue. Based on our theoretical and empirical analysis, we propose Deep Adaptive Graph Neural Network (DAGNN) to adaptively incorporate information from large receptive fields. A set of experiments on citation, co-authorship, and co-purchase datasets have confirmed our analysis and insights and demonstrated the superiority of our proposed methods.
Using LSTMs to Model the Java Programming Language

Recurrent neural networks (RNNs), specifically long-short term memory networks (LSTMs), can model natural language effectively. This research investigates the ability for these same LSTMs to perform next “word” prediction on the Java programming language. Java source code from four different repositories undergoes a transformation that preserves the logical structure of the source code and removes the code’s various specificities such as variable names and literal values. Such datasets and an additional English language corpus are used to train and test standard LSTMs’ ability to predict the next element in a sequence. Results suggest that LSTMs can effectively model Java code achieving perplexities under 22 and accuracies above 0.47, which is an improvement over LSTM’s performance on the English language which demonstrated a perplexity of 85 and an accuracy of 0.27. This research can have applicability in other areas such as syntactic template suggestion and automated bug patching.
Emission-Line Properties of the Optical Filaments of NGC 1275

Extended nebular filaments are seen at optical wavelengths in NGC 1275, the central galaxy in the Perseus cluster. The agents responsible for the excitation of these filaments remain poorly understood. In this paper we investigate possible mechanisms for powering the filaments, using measurements from an extensive spectroscopic data set acquired at the Lick Observatory 3 m Shane telescope. The results show that the filaments are in an extremely low ionization and excitation state. The high signal-to-noise ratio of the spectra allows us to measure or place sensitive upper limits on weak but important diagnostic lines. We compare the observed line intensity ratios to the predictions of various ionization models, including photoionization by an active galactic nucleus, shock heating, stellar photoionization, and photoionization by the intracluster medium. We also investigate possible roles for cluster extreme-ultraviolet emission, and filtering of cluster soft X-ray emission by an ionized screen, in the energetics of the filaments. None of these mechanisms provides an entirely satisfactory explanation for the physical state of the nebulae. Heating and ionization by reconnection of the intracluster magnetic field remains a potentially viable alternative, which merits further investigation through Faraday rotation studies.
A Panchromatic View of Brown Dwarf Aurorae

Stellar coronal activity has been shown to persist into the low-mass star regime, down to late M-dwarf spectral types. However, there is now an accumulation of evidence suggesting that at the end of the main sequence, there is a transition in the nature of the magnetic activity from chromospheric and coronal to planet-like and auroral, from local impulsive heating via flares and MHD wave dissipation to energy dissipation from strong large-scale magnetospheric current systems. We examine this transition and the prevalence of auroral activity in brown dwarfs through a compilation of multiwavelength surveys of magnetic activity, including radio, X-ray, and optical. We compile the results of those surveys and place their conclusions in the context of auroral emission as a consequence of large-scale magnetospheric current systems that accelerate energetic electron beams and drive the particles to impact the cool atmospheric gas. We explore the different manifestations of auroral phenomena, like Hα, in brown dwarf atmospheres and define their distinguishing characteristics. We conclude that large-amplitude photometric variability in the near-infrared is most likely a consequence of clouds in brown dwarf atmospheres, but that auroral activity may be responsible for long-lived stable surface features. We report a connection between auroral Hα emission and quiescent radio emission in electron cyclotron maser instability pulsing brown dwarfs, suggesting a potential underlying physical connection between quiescent and auroral emissions. We also discuss the electrodynamic engines powering brown dwarf aurorae and the possible role of satellites around these systems both to power the aurorae and seed the magnetosphere with plasma.
Self-assembled Zeeman slower based on spherical permanent magnets

We present a novel type of longitudinal Zeeman slower. The magnetic field profile is generated by a 3D array of permanent spherical magnets, which are self-assembled into a stable structure. The simplicity and stability of the design make it quick to assemble and inexpensive. In addition, as with other permanent magnet slowers, no electrical current or water cooling is required. We describe the theory, assembly, and testing of this new design.
Analytic classes of metastable de Sitter vacua

In this paper, we give a systematic procedure for building locally stable dS vacua in $$ \mathcal{N}=1 $$ supergravity models motivated by string theory. We assume that one of the superfields has a Kahler potential of no-scale type and impose a hierarchy of supersymmetry breaking conditions. In the no-scale modulus direction the supersymmetry breaking is not small, in all other directions it is of order ϵ. We establish the existence of an abundance of vacua for large regions in the parameter space spanned by ϵ and the cosmological constant. These regions exist regardless of the details of the other moduli, provided the superpotential can be tuned such that the off-diagonal blocks of the mass matrix are parametrically small. We test and support this general dS landscape construction by explicit analytic solutions for the STU model. The Minkowski limits of these dS vacua either break supersymmetry or have flat directions in agreement with a no-go theorem that we prove, stating that a supersymmetric Minkowski vacuum without flat directions cannot be continuously deformed into a non-supersymmetric vacuum. We also describe a method for finding a broad class of stable supersymmetric Minkowski vacua that can be F-term uplifted to dS vacua and which have an easily controllable SUSY breaking scale.
Shock Breakout from Type Ia Supernova

The mode of explosive burning in Type Ia supernovae (SNe Ia) remains an outstanding problem. It is generally thought to begin as a subsonic deflagration, but this may transition into a supersonic detonation (the delayed detonation transition, DDT). We argue that this transition leads to a breakout shock, which would provide the first unambiguous evidence that DDTs occur. Its main features are a hard X-ray flash (~20 keV) lasting ~10–2 s with a total radiated energy of ~1040 erg, followed by a cooling tail. This creates a distinct feature in the visual light curve, which is separate from the nickel decay. This cooling tail has a maximum absolute visual magnitude of MV ≈ –9 to –10 at ≈1 day, which depends most sensitively on the white dwarf radius at the time of the DDT. As the thermal diffusion wave moves in, the composition of these surface layers may be imprinted as spectral features, which would help to discern between SN Ia progenitor models. Since this feature should accompany every SNe Ia, future deep surveys (e.g., m = 24) will see it out to a distance of ≈80 Mpc, giving a maximum rate of ~60 yr-1. Archival data sets can also be used to study the early rise dictated by the shock heating (at ≈20 days before maximum B-band light). A similar and slightly brighter event may also accompany core bounce during the accretion-induced collapse to a neutron star, but with a lower occurrence rate.
Automatic design of Hamiltonians

We formulate an optimization problem of Hamiltonian design based on the variational principle. Given a variational ansatz for a Hamiltonian we construct a loss function to be minimised as a weighted sum of relevant Hamiltonian properties specifying thereby the search query. Using fractional quantum Hall effect as a test system we illustrate how the framework can be used to determine a generating Hamiltonian of a finite-size model wavefunction (Moore-Read Pfaffian and Read-Rezayi states), find optimal conditions for an experiment or "extrapolate" given wavefunctions in a certain universality class from smaller to larger system sizes. We also discuss how the search for approximate generating Hamiltonians may be used to find simpler and more realistic models implementing the given exotic phase of matter by experimentally accessible interaction terms.
Iterative precision measurement of branching ratios applied to 5P states in 88Sr

We report and demonstrate a method for measuring the branching ratios of dipole transitions of trapped atomic ions by performing nested sequences of population inversions. This scheme is broadly applicable to species with metastable lambda systems and can be generalized to find the branching of any state to lowest states. It does not use ultrafast pulsed or narrow linewidth lasers and is insensitive to experimental variables such as laser and magnetic field noise as well as ion heating. To demonstrate its effectiveness, we make the most accurate measurements thus far of the branching ratios of both and states in 88Sr+ with sub-1% uncertainties. We measure 17.175(27) for the – branching ratio, 15.845(71) for –, and 0.056 09(21) for –. These values represent the first precision measurement for –, as well as ten- and thirty-fold improvements in precision respectively for – and – over the best previous experimental values.
Fixed point theorem for reflexive Banach spaces and uniformly convex non positively curved metric spaces

This article generalizes the work of Ballmann and Światkowski to the case of Reflexive Banach spaces and uniformly convex Busemann spaces, thus giving a new fixed point criterion for groups acting on simplicial complexes.
The Leptoquark Hunter's Guide: Large Coupling

Leptoquarks have recently received much attention especially because they may provide an explanation to the $$ {R}_{D^{\left(*\right)}}\kern0.5em \mathrm{and}\kern0.5em {R}_{K^{\left(*\right)}} $$ anomalies in rare B meson decays. In a previous paper we proposed a systematic search strategy for all possible leptoquark flavors by focusing on leptoquark pair production. In this paper, we extend this strategy to large (order unity) leptoquark couplings which offer new search opportunities: single leptoquark production and t-channel leptoquark exchange with dilepton final states. We discuss the unique features of the different search channels and show that they cover complementary regions of parameter space. We collect and update all currently available bounds for the different flavor final states from LHC searches and from atomic parity violation measurements. As an application of our analysis, we find that current limits do not exclude a leptoquark explanation of the B physics anomalies but that the high luminosity run of the LHC will reach the most interesting parameter space.
On the Mass Distribution and Birth Masses of Neutron Stars

We investigate the distribution of neutron star masses in different populations of binaries, employing Bayesian statistical techniques. In particular, we explore the differences in neutron star masses between sources that have experienced distinct evolutionary paths and accretion episodes. We find that the distribution of neutron star masses in non-recycled eclipsing high-mass binaries as well as of slow pulsars, which are all believed to be near their birth masses, has a mean of 1.28 M ☉ and a dispersion of 0.24 M ☉. These values are consistent with expectations for neutron star formation in core-collapse supernovae. On the other hand, double neutron stars, which are also believed to be near their birth masses, have a much narrower mass distribution, peaking at 1.33 M ☉, but with a dispersion of only 0.05 M ☉. Such a small dispersion cannot easily be understood and perhaps points to a particular and rare formation channel. The mass distribution of neutron stars that have been recycled has a mean of 1.48 M ☉ and a dispersion of 0.2 M ☉, consistent with the expectation that they have experienced extended mass accretion episodes. The fact that only a very small fraction of recycled neutron stars in the inferred distribution have masses that exceed ~2 M ☉ suggests that only a few of these neutron stars cross the mass threshold to form low-mass black holes.
Subleading Power Factorization with Radiative Functions

The study of amplitudes and cross sections in the soft and collinear limits allows for an understanding of their all orders behavior, and the identification of universal structures. At leading power soft emissions are eikonal, and described by Wilson lines. Beyond leading power the eikonal approximation breaks down, soft fermions must be added, and soft radiation resolves the nature of the energetic partons from which they were emitted. For both subleading power soft gluon and quark emissions, we use the soft collinear effective theory (SCET) to derive an all orders gauge invariant bare factorization, at both amplitude and cross section level. This yields universal multilocal matrix elements, which we refer to as radiative functions. These appear from subleading power Lagrangians inserted along the lightcone which dress the leading power Wilson lines. The use of SCET enables us to determine the complete set of radiative functions that appear to $$ \mathcal{O} $$ (λ2) in the power expansion, to all orders in αs. For the particular case of event shape observables in e+e−→ dijets we derive how the radiative functions contribute to the factorized cross section to $$ \mathcal{O} $$ (λ2).
Extinction, periodicity and multistability in a Ricker model of stage-structured populations

We study the dynamics of a second-order difference equation that is derived from a planar Ricker model of two-stage (adult-juvenile) biological populations. We obtain sufficient conditions for global convergence to zero in the non-autonomous case yielding general conditions for extinction in the biological context. We also study the dynamics of an autonomous special case of the equation that generates multistable periodic and non-periodic orbits in the positive quadrant of the plane.
Vortex fiber nulling for exoplanet observations: conceptual design, theoretical performance, and initial scientific yield predictions

Vortex fiber nulling (VFN) is a method that may enable the detection and characterization of exoplanets at small angular separations (0.5-2 λ/D) with ground- and space-based telescopes. Since the field of view is within the inner working angle of most coronagraphs, nulling accesses non-transiting planets that are otherwise too close to their star for spectral characterization by other means, thereby significantly increasing the number of known exoplanets available for direct spectroscopy in the near-infrared. Furthermore, VFN targets planets on closer-in orbits which tend to have more favorable planet-to-star flux ratios in reflected light. Here, we present the theory and applications of VFN, show that the optical performance is approximately equivalent for a variety of implementations and aperture shapes, and discuss the trade-offs between throughput and engineering requirements using numerical simulations. We compare vector and scalar approaches and, finally, show that beam shaping optics may be used to significantly improve the throughput for planet light. Based on theoretical performance, we estimate the number of known planets and theoretical exoEarths accessible with a VFN instrument linked to a high-resolution spectrograph on the future Thirty Meter Telescope.
q-UNCERTAINTY RELATIONS

As oen would anticipate from the realization of the q-commutators by difference operators, the states of maximum localization are smeared δ-functions dependeing on q.
The Presence of Dust and Ice Scattering in X-Ray Emissions from Comets

X-ray emissions from cometary atmospheres were modeled from first principles using the charge-exchange interaction with solar wind ions as well as coherent scattering of solar X-rays from dust and ice grains. Scattering cross-sections were interpolated over the 1 nm–1 cm grain radius range using approximations based on the optically thin or thick nature of grains with different sizes. The theoretical emission model was compared to Chandra observations of Comets ISON and Ikeya–Zhang due to their high signal-to-noise ratios and clearly defined spectral features. Comparing the observed intensities to the model showed that the charge-exchange mechanism accurately reproduced the emission spectra below 1 keV, while dust and ice scattering was negligible. Examining the 1–2 keV range found dust and ice scattering emissions to agree well with observations, while charge-exchange contributions were insignificant. Spectral features between the scattering model and observations also trended similarly over the 1–2 keV range. The dust and ice density within the cometary atmosphere n was varied with respect to grain size a as the function , with Ikeya–Zhang requiring and ISON requiring to best fit the observed spectral intensities. These grain size dependencies agreed with independent observations and simulations of such systems. The overall findings demonstrate evidence of significant scattering emissions present above 1 keV in the analyzed cometary emission spectra and that the dust/ice density dependence on grain radius a may vary significantly between comets.
Chains of saturated models in AECs

We study when a union of saturated models is saturated in the framework of tame abstract elementary classes (AECs) with amalgamation. We prove: Theorem 0.1.IfKis a tame AEC with amalgamation satisfying a natural definition of superstability (which follows from categoricity in a high-enough cardinal), then for all high-enough$$\lambda {:}$$ź:(1)The union of an increasing chain of$$\lambda $$ź-saturated models is$$\lambda $$ź-saturated.(2)There exists a type-full good$$\lambda $$ź-frame with underlying class the saturated models of size$$\lambda $$ź.(3)There exists a unique limit model of size$$\lambda $$ź. Our proofs use independence calculus and a generalization of averages to this non first-order context.
Think Globally, Act Locally: On the Optimal Seeding for Nonsubmodular Influence Maximization.

We study the r-complex contagion influence maximization problem. In the influence maximization problem, one chooses a fixed number of initial seeds in a social network to maximize the spread of their influence. In the r-complex contagion model, each uninfected vertex in the network becomes infected if it has at least r infected neighbors. In this paper, we focus on a random graph model named the stochastic hierarchical blockmodel, which is a special case of the well-studied stochastic blockmodel. When the graph is not exceptionally sparse, in particular, when each edge appears with probability omega (n^{-(1+1/r)}), under certain mild assumptions, we prove that the optimal seeding strategy is to put all the seeds in a single community. This matches the intuition that in a nonsubmodular cascade model placing seeds near each other creates synergy. However, it sharply contrasts with the intuition for submodular cascade models (e.g., the independent cascade model and the linear threshold model) in which nearby seeds tend to erode each others' effects. Finally, we show that this observation yields a polynomial time dynamic programming algorithm which outputs optimal seeds if each edge appears with a probability either in omega (n^{-(1+1/r)}) or in o (n^{-2}).
Solar differential rotation: hints to reproduce a near-surface shear layer in global simulations

Convective turbulent motions in the solar interior, as well as the mean flows resulting from them, determine the evolution of the solar magnetic field. With the aim to get a better understanding of these flows we study anelastic rotating convection in a spherical shell whose stratification resembles that of the solar interior. This study is done through numerical simulations performed with the EULAG code. Due to the numerical formulation, these simulations are known as implicit large eddy simulations (ILES), since they intrinsically capture the contribution of, non-resolved, small scales at the same time maximizing the effective Reynolds number. We reproduce some previous results and find a transition between buoyancy and rotation dominated regimes which results in anti-solar or solar like rotation patterns. Even thought the rotation profiles are dominated by Taylor-Proudman columnar rotation, we are able to reproduce the tachocline and a low latitude near-surface shear layer. We find that simulations results depend on the grid resolution as a consequence of a different sub-grid scale contribution.
Learning Robust and Multilingual Speech Representations

Unsupervised speech representation learning has shown remarkable success at finding representations that correlate with phonetic structures and improve downstream speech recognition performance. However, most research has been focused on evaluating the representations in terms of their ability to improve the performance of speech recognition systems on read English (e.g. Wall Street Journal and LibriSpeech). This evaluation methodology overlooks two important desiderata that speech representations should have: robustness to domain shifts and transferability to other languages. In this paper we learn representations from up to 8000 hours of diverse and noisy speech data and evaluate the representations by looking at their robustness to domain shifts and their ability to improve recognition performance in many languages. We find that our representations confer significant robustness advantages to the resulting recognition systems: we see significant improvements in out-of-domain transfer relative to baseline feature sets and the features likewise provide improvements in 25 phonetically diverse languages.
Diffuse Far-UV Line Emission from the Low-redshift Lyman Break Galaxy Analog KISSR242

We present new ultraviolet (UV) observations of the luminous compact blue galaxy KISSR242, obtained with the Hubble Space Telescope-Cosmic Origins Spectrograph (HST-COS). We identify multiple resolved sub-arcsecond near-UV sources within the COS aperture. The far-UV spectroscopic data show strong outflow absorption lines, consistent with feedback processes related to an episode of massive star formation. O I, C II, and Si II-Si IV are observed with a mean outflow velocity v out = –60 km s–1. We also detect faint fine-structure emission lines of singly ionized silicon for the first time in a low-redshift starburst galaxy. These emissions have been seen previously in deep Lyman break galaxy surveys at z ~ 3. The Si II* lines are at the galaxy rest velocity, and they exhibit a quantitatively different line profile from the absorption features. These lines have a width of ≈75 km s–1, too broad for point-like emission sources such as the H II regions surrounding individual star clusters. The size of the Si II* emitting region is estimated to be ≈250 pc. We discuss the possibility of this emission arising in overlapping super star cluster H II regions, but find this explanation to be unlikely in light of existing far-UV observations of local star-forming galaxies. We suggest that the observed Si II* emission originates in a diffuse warm halo populated by interstellar gas driven out by intense star formation and/or accreted during a recent interaction that may be fueling the present starburst episode in KISSR242.
Bezout Inequality for Mixed Volumes

In this paper we consider the following analog of Bezout inequality for mixed volumes: $$V(P_1,\dots,P_r,\Delta^{n-r})V_n(\Delta)^{r-1}\leq \prod_{i=1}^r V(P_i,\Delta^{n-1})\ \text{ for }2\leq r\leq n.$$ We show that the above inequality is true when $\Delta$ is an $n$-dimensional simplex and $P_1, \dots, P_r$ are convex bodies in $\mathbb{R}^n$. We conjecture that if the above inequality is true for all convex bodies $P_1, \dots, P_r$, then $\Delta$ must be an $n$-dimensional simplex. We prove that if the above inequality is true for all convex bodies $P_1, \dots, P_r$, then $\Delta$ must be indecomposable (i.e. cannot be written as the Minkowski sum of two convex bodies which are not homothetic to $\Delta$), which confirms the conjecture when $\Delta$ is a simple polytope and in the 2-dimensional case. Finally, we connect the inequality to an inequality on the volume of orthogonal projections of convex bodies as well as prove an isomorphic version of the inequality.
Exploring Properties of Dark and Visible Mass Distribution on Different Scales in the Universe

In this short note we discuss recent observation of linear correlation on log-log scale between distribution of dark and visible mass in gravitationally bound systems. The coefficient of such correlation appears to be essentially the same for various systems of dramatically different scales such as spiral galaxies of different luminosities and galaxy clusters. We briefly touch possible interpretations of this observation and implications for the mass of dark matter particle.
The hydroxyl-water megamaser connection. I. Water emission toward OH megamaser hosts

Questions surround the connection of luminous extragalactic masers to galactic processes. The observation that water and hydroxyl megamasers rarely coexist in the same galaxy has given rise to a hypothesis that the two species appear in different phases of nuclear activity. The detection of simultaneous hydroxyl and water megamaser emission toward IC694 has called this hypothesis into question, but, because many megamasers have not been surveyed for emission in the other molecule, it remains unclear whether IC694 occupies a narrow phase of galaxy evolution or whether the relationship between megamaser species and galactic processes is more complicated than previously believed. In this paper, we present results of a systematic search for 22 GHz water maser emission among OH megamaser hosts to identify additional objects hosting both megamasers. Our work roughly doubles the number of galaxies searched for emission in both molecules, which host at least one confirmed maser. We confirm with a high degree of confidence ($$\gt 8\sigma $$) the detection of water emission toward IIZw96, firmly establishing it as the second object to cohost both water and hydroxyl megamasers after IC694. We find high luminosity, narrow features in the water feature in IIZw96. All dual megamaser candidates appear in merging galaxy systems suggestive that megamasers that coexistance may signal a brief phase along the merger sequence. In conclusion, a statistical analysis of the results of our observations provide possible evidence for an exclusion of H2O kilomasers among OH megamaser hosts.
$$N^*$$ Resonances in Lattice QCD from (Mostly) Low to (Sometimes) High Virtualities

I present a survey of calculations of the excited \(N^*\) spectrum in lattice QCD. I then describe recent advances aimed at extracting the momentum-dependent phase shifts from lattice calculations, notably in the meson sector, and the potential for their application to baryons. I conclude with a discussion of calculations of the electromagnetic transition form factors to excited nucleons, including calculations at high \(Q^2\).
Convex projective manifolds with a cusp of any non‐diagonalizable type

Recent work of Ballas, Cooper, and Leitner identifies $(n+1)$ types of $n$-dimensional convex projective cusps, one of which is the standard hyperbolic cusp. Work of Ballas-Marquis, and Ballas-Danciger-Lee give examples of these exotic (non-hyperbolic) type cusps in dimension $3$. Here an extension of the techniques of Ballas-Marquis shows the existence of all cusp types in all dimensions, except diagonalizable (type $n$).
An analogue of Hawking radiation in the quantum Hall effect

The edge of a droplet of lowest Landau-level quantum Hall fluid provides a model for a 1 + 1 dimensional chiral Dirac fermion. We use this fact to construct an analogue model for a chiral fermion in a space-time geometry possessing an event horizon. We show that the analogue horizon emits particles and holes with a thermal spectrum. Each emitted quasiparticle is correlated with an opposite-energy partner on the other side of the horizon. Once we trace out these ?unobservable? partners, we are left with a thermal density matrix. For typical quantum Hall device parameters, the predicted ?Hawking? temperature is about 2?K.
On the Time Variability of the Star Formation Efficiency

A star formation efficiency per free-fall time that evolves over the lifetime of giant molecular clouds (GMCs) may have important implications for models of supersonic turbulence in molecular clouds or for the relation between the star formation rate and H2 surface density. We discuss observational data that could be interpreted as evidence of such a time variability. In particular, we investigate a recent claim based on measurements of H2 and stellar masses in individual GMCs. We show that this claim depends crucially on the assumption that H2 masses do not evolve over the lifetimes of GMCs. We exemplify our findings with a simple toy model that uses a constant star formation efficiency and, yet, is able to explain the observational data.
ON THE QUANTUM FILTRATION OF THE UNIVERSAL sl(2) FOAM COHOMOLOGY

We investigate the filtered theory corresponding to the universal sl(2) foam cohomology ${\mathcal H_{a, h}^*}$ for links, where a, h ∈ ℂ. We show that there is a spectral sequence converging to ${\mathcal H_{a, h}^*}$ which is invariant under the Reidemeister moves, and whose E1 term is isomorphic to Khovanov homology. This spectral sequence can be used to obtain from the foam perspective an analogue of the Rasmussen invariant and a lower bound for the slice genus of a knot.
Tuning Word2vec for Large Scale Recommendation Systems

Word2vec is a powerful machine learning tool that emerged from Natural Language Processing (NLP) and is now applied in multiple domains, including recommender systems, forecasting, and network analysis. As Word2vec is often used off the shelf, we address the question of whether the default hyperparameters are suitable for recommender systems. The answer is emphatically no. In this paper, we first elucidate the importance of hyperparameter optimization and show that unconstrained optimization yields an average 221% improvement in hit rate over the default parameters. However, unconstrained optimization leads to hyperparameter settings that are very expensive and not feasible for large scale recommendation tasks. To this end, we demonstrate 138% average improvement in hit rate with a runtime budget-constrained hyperparameter optimization. Furthermore, to make hyperparameter optimization applicable for large scale recommendation problems where the target dataset is too large to search over, we investigate generalizing hyperparameters settings from samples. We show that applying constrained hyperparameter optimization using only a 10% sample of the data still yields a 91% average improvement in hit rate over the default parameters when applied to the full datasets. Finally, we apply hyperparameters learned using our method of constrained optimization on a sample to the Who To Follow recommendation service at Twitter and are able to increase follow rates by 15%.
Electromigration dispersion in a capillary in the presence of electro-osmotic flow

The differential migration of ions in an applied electric field is the basis for the separation of chemical species by capillary electrophoresis. Axial diffusion of the concentration peak limits the separation efficiency. Electromigration dispersion is observed when the concentration of sample ions is comparable to that of the background ions. Under such conditions, the local electrical conductivity is significantly altered in the sample zone making the electric field, and, therefore, the ion migration velocity, concentration dependent. The resulting nonlinear wave exhibits shock-like features and, under certain simplifying assumptions, is described by Burgers’ equation (Ghosal & Chen Bull. Math. Biol., vol. 72, 2010, p. 2047). In this paper, we consider the more general situation where the walls of the separation channel may have a non-zero zeta potential and are therefore able to sustain an electro-osmotic bulk flow. The main result is a one-dimensional nonlinear advection diffusion equation for the area averaged concentration. This homogenized equation accounts for the Taylor–Aris dispersion resulting from the variation in the electro-osmotic slip velocity along the wall. It is shown that in a certain range of parameters, the electro-osmotic flow can actually reduce the total dispersion by delaying the formation of a concentration shock. However, if the electro-osmotic flow is sufficiently high, the total dispersion is increased because of the Taylor–Aris contribution.
Formation and Propagation of Discontinuity for Boltzmann Equation in Non-Convex Domains

The formation and propagation of singularities for the Boltzmann equation in bounded domains has been an important question in numerical studies as well as in theoretical studies. In this paper, we consider the nonlinear Boltzmann solution near Maxwellians under in-flow, diffuse, or bounce-back boundary conditions. We demonstrate that discontinuity is created at the non-convex part of the grazing boundary, and then it propagates only along the forward characteristics inside the domain before it hits on the boundary again.
High Voltage CMOS control interface for astronomy—Grade charged coupled devices

The Pan-STARRS telescope consists of an array of smaller mirrors viewed by a Giga-pixel arrays of CCDs. These focal planes employ Orthogonal Transfer CCDs (OTCCDs) to allow on-chip image stabilization. Each OTCCD has advanced logic features that are controlled externally. A CMOS Interface Device for High Voltage has been developed to provide the appropiate voltage signal levels from a readout and control system designated STARGRASP. OTCCD chip output levels range from -3.3V to 16.7V, with two different output drive strengths required depending on load capacitance (50pF and 1000pF), with 24mA of drive and a rise time on the order of 100ns. Additional testing Wilkinson ADC structures have been included in this chip to evaluate future functional additions for a next version of the chip.
Nonequilibrium quantum dynamics and transport: from integrability to many-body localization

We review the non-equilibrium dynamics of many-body quantum systems after a quantum quench with spatial inhomogeneities, either in the Hamiltonian or in the initial state. We focus on integrable and many-body localized systems that fail to self-thermalize in isolation and for which the standard hydrodynamical picture breaks down. The emphasis is on universal dynamics, non-equilibrium steady states and new dynamical phases of matter, and on phase transitions far from thermal equilibrium. We describe how the infinite number of conservation laws of integrable and many-body localized systems lead to complex non-equilibrium states beyond the traditional dogma of statistical mechanics.
Duality of 2D Gravity as a Local Fourier Duality

The p–q duality is a relation between the (p, q) model and the (q, p) model of two-dimensional quantum gravity. Geometrically this duality corresponds to a relation between the two relevant points of the Sato Grassmannian. Kharchev and Marshakov have expressed such a relation in terms of matrix integrals. Some explicit formulas for small p and q have been given in the work of Fukuma-Kawai-Nakayama. Already in the duality between the (2, 3) model and the (3, 2) model the formulas are long. In this work a new approach to p–q duality is given: It can be realized in a precise sense as a local Fourier duality of D-modules. This result is obtained as a special case of a local Fourier duality between irregular connections associated to Kac–Schwarz operators. Therefore, since these operators correspond to Virasoro constraints, this allows us to view the p–q duality as a consequence of the duality of the relevant Virasoro constraints.
Colors and Kinematics of L Dwarfs from the Sloan Digital Sky Survey

We present a sample of 484 L dwarfs, 210 of which are newly discovered from the Sloan Digital Sky Survey (SDSS) Data Release 7 spectroscopic database. We combine this sample with known L dwarfs to investigate their izJHKS colors. Our spectroscopically selected sample has ~0.1 mag bluer median J – KS color at a given spectral type (for L0-L4) than previously known L dwarfs, which reflects a bias toward redder L dwarfs in past selection criteria. We present photometric distance relations based on i – z and i – J colors and derive distances to our L dwarf sample. We combine the distances with SDSS/2MASS proper motions in order to examine the tangential velocities. For the majority of our spectroscopic sample, we measured radial velocities and present three-dimensional kinematics. We also provide Hα detections for the fraction of our sample with sufficient quality spectra. Comparison of the velocities of our L dwarf sample to a kinematic model shows evidence for both cold and hot dynamical populations, consistent with young and old disk components. The dispersions of these components are similar to those found for M dwarfs. We also show that J – KS color is correlated with velocity dispersion, confirming a relationship between J – KS color and age.