cssi/SciSciGPT-SciSciNet huggingface dataset:
Sets of Half-Average Nulls Generate Risk-Limiting Audits: SHANGRLA

Risk-limiting audits (RLAs) for many social choice functions can be reduced to testing sets of null hypotheses of the form “the average of this list is not greater than 1/2” for a collection of finite lists of nonnegative numbers. Such social choice functions include majority, super-majority, plurality, multi-winner plurality, Instant Runoff Voting (IRV), Borda count, approval voting, and STAR-Voting, among others. The audit stops without a full hand count iff all the null hypotheses are rejected. The nulls can be tested in many ways. Ballot polling is particularly simple; two new ballot-polling risk-measuring functions for sampling without replacement are given. Ballot-level comparison audits transform each null into an equivalent assertion that the mean of re-scaled tabulation errors is not greater than 1/2. In turn, that null can then be tested using the same statistical methods used for ballot polling—applied to different finite lists of nonnegative numbers. The SHANGRLA approach thus reduces auditing different social choice functions and different audit methods to the same simple statistical problem. Moreover, SHANGRLA comparison audits are more efficient than previous comparison audits for two reasons: (i) for most social choice functions, the conditions tested are both necessary and sufficient for the reported outcome to be correct, while previous methods tested conditions that were sufficient but not necessary, and (ii) the tests avoid a conservative approximation. The SHANGRLA abstraction simplifies stratified audits, including audits that combine ballot polling with ballot-level comparisons, producing sharper audits than the “SUITE” approach. SHANGRLA works with the “phantoms to evil zombies” strategy to treat missing ballot cards and missing or redacted cast vote records. That also facilitates sampling from “ballot-style manifests,” which can dramatically improve efficiency when the audited contests do not appear on every ballot card. Open-source software implementing SHANGRLA ballot-level comparison audits is available. SHANGRLA was tested in a process pilot audit of an instant-runoff contest in San Francisco, CA, in November, 2019.
Reproducing inequity: the role of race in the business school faculty search

Despite an increase in students of colour in higher education, a concomitant rise in faculty diversity is not evident. The present research focuses on faculty composition in business schools, which...
Tumor-on-a-chip platform to interrogate the role of macrophages in tumor progression

Tumor-infiltrating leukocytes, in particular macrophages, play an important role in tumor behavior and clinical outcome. The spectrum of macrophage subtypes ranges from antitumor 'M1'-type to protumor 'M2'-type macrophages. Tumor-associated macrophages (TAMs) typically display phenotypic features of both M1 and M2, and the population distribution is thought to be dynamic and evolves as the tumor progresses. However, our understanding of how TAMs impact the tumor microenvironment remains limited by the lack of appropriate 3D in vitro models that can capture cell-cell dynamics at high spatial and temporal resolution. Using our recently developed microphysiological 'tumor-on-a-chip' (TOC) device, we present here our findings on the impact of defined macrophage subsets on tumor behavior. The TOC device design contains three adjacent and connected chambers in which both the upper and lower chambers are loaded with tumor cells, whereas the central chamber contains a dynamic, perfused, living microvascular network. Introduction of human pancreatic or colorectal cancer cells together with M1-polarized macrophages significantly inhibited tumor growth and tumor-induced angiogenesis. Protein analysis and antibody-based neutralization studies confirmed that these effects were mediated through production of C-X-C motif chemokines (CXCL9), CXCL10 and CXCL11. By contrast, M2-macrophages mediated increased tumor cell migration into the vascularized chamber and did not inhibit tumor growth or angiogenesis. In fact, single-cell RNA sequencing showed that M2 macrophages further segregated endothelial cells into two distinct subsets, corresponding to static cells in vessels versus active cells involved in angiogenesis. The impact of M2 macrophages was mediated mostly by production of matrix metalloproteinase 7 and angiopoietin 2. In summary, our data demonstrate the utility of the TOC device to mechanistically probe biological questions in a 3D in vitro microenvironment.
Menthol in Electronic Cigarettes: A Contributor to Respiratory Disease?

Menthol is widely used in tobacco products. This study compared the effects of menthol on human bronchial epithelium using submerged cultures, a VITROCELL® cloud chamber that provides air liquid interface (ALI) exposure without solvents or heating, and a Cultex ALI system that delivers aerosol equivalent to that inhaled during vaping. In submerged culture, menthol significantly increased calcium influx and mitochondrial reactive oxygen species (ROS) via the TRPM8 receptor, responses that were inhibited by a TRPM8 antagonist. VITROCELL® cloud chamber exposure of BEAS-2B monolayers increased mitochondrial protein oxidation, expression of the antioxidant enzyme SOD2, activation of NF-κB, and secretion of inflammatory cytokines (IL-6 and IL-8). Proteomics data collected following ALI exposure of 3D EpiAirway tissue in the Cultex showed upregulation of NRF-2-mediated oxidative stress, oxidative phosphorylation, and IL-8 signaling. Across the three platforms, menthol adversely effected human bronchial epithelium in a manner that could lead to respiratory disease.
Family Resilience and Connection Is Associated with Dental Caries in US Children

INTRODUCTION The impact of family resilience and connection on children's oral health has not been well-documented in the published literature. OBJECTIVES This study examined the association between family resilience and connection and the probability of a child having caregiver-reported dental caries using a nationally representative sample. METHODS A cross-sectional analysis of the 2016 National Survey of Children's Health was performed on US children ages 6 to 17 y. Family resilience and connection was assessed using a 6-point index and analyzed as a 3-level categorical variable. Caregivers reported whether their child had "decayed teeth or cavities" during the past 12 mo. Logistic regression was performed controlling for child (age, gender, race/ethnicity, insurance, preventive dental use) and family (education and federal poverty level) characteristics. RESULTS Among the 35,167 children in the sample, 10.4% children had caregiver-reported dental caries. The prevalence of dental caries decreased in a graded fashion with increasing levels of family resilience and connection (12.5%, 10.5%, and 8.8%, respectively; P < 0.001). As compared with children with the lowest level of family resilience and connection, those with the highest level had lower odds of caregiver-reported dental caries after adjusting for child and family covariates (adjusted odds ratio = 0.63; 95% confidence interval = 0.58, 0.69). CONCLUSION Using a nationally representative sample, children living in families with higher levels of resilience and connection had a significantly lower odds of caregiver-reported dental caries. Policies and programs that increase family resilience and connection have the potential to decrease dental caries in school-aged children. KNOWLEDGE TRANSFER STATEMENT This work suggests an association between family resilience/connection and dental caries in school-aged children. Further work is required to determine the degree to which addressing these constructs might impact child dental caries.
Endoscopic transoral nasopharyngectomy.

BACKGROUND A minimal access technique for the management of nasopharyngeal tumors extending below the palatal plane and laterally beyond the pterygoid musculature is yet to be developed. In this study we demonstrate the feasibility of endoscopic transoral nasopharyngectomy (ETON) for resection of large nasopharyngeal lesions as a natural orifice alternative to traditional approaches. METHODS ETON was completed in three latex-injected specimens. Surgical freedom (SF) and angles of attack (AoA) were calculated along the internal carotid artery (ICA). RESULTS An endoscopic transoral approach was successfully used to identify the parapharyngeal ICA and subsequently perform a complete nasopharyngeal resection. SF and AoA (sagittal) were found to be the greatest at the anterior genu of the ICA. CONCLUSIONS ETON is feasible. It provides wide exposure of the skull base and proximal control of the ICA. It may be indicated for the management of nasopharyngeal tumors with inferolateral extension, involving the ICA.
Upper bounds of nodal sets for eigenfunctions of eigenvalue problems

The aim of this article is to provide a simple and unified way to obtain the sharp upper bounds of nodal sets of eigenfunctions for different types of eigenvalue problems on real analytic domains. The examples include biharmonic Steklov eigenvalue problems, buckling eigenvalue problems and champed-plate eigenvalue problems. The geometric measure of nodal sets are derived from doubling inequalities and growth estimates for eigenfunctions. It is done through analytic estimates of Morrey–Nirenberg and Carleman estimates.
Excitation spectra of quantum matter without quasiparticles. I. Sachdev-Ye-Kitaev models

We study the low-frequency spectra of complex Sachdev-Ye-Kitaev models at general densities. The analysis applies also to $\mathrm{SU}(M)$ magnets with random exchange at large $M$. The spectral densities are computed by numerical analysis of the saddle-point equations on the real frequency $\ensuremath{\omega}$ axis at zero temperature $T$. The asymptotic low-$\ensuremath{\omega}$ behaviors are found to be in excellent agreement with the scaling dimensions of irrelevant operators which perturb the conformally invariant critical states. Of possible experimental interest is our computation of the universal spin spectral weight of the $\mathrm{SU}(M)$ magnets at low $\ensuremath{\omega}$ and $T$; this includes a contribution from the time reparametrization mode, which is the boundary graviton of the holographic dual. This analysis is extended to a random $t\ensuremath{-}J$ model in the following paper [M. Tikhanovskaya et al., following paper, Phys. Rev. B 103, 075142 (2021)].
Consequences of hot gas in the broad-line region of active galactic nuclei

Models for hot gas in the broad line region of active galactic nuclei are discussed. The results of the two phase equilibrium models for confinement of broad line clouds by Compton heated gas are used to show that high luminosity quasars are expected to show Fe XXVI L alpha line absorption which will be observed with spectrometers such as those planned for the future X-ray spectroscopy experiments. Two phase equilibrium models also predict that the gas in the broad line clouds and the confining medium may be Compton thick. It is shown that the combined effects of Comptonization and photoabsorption can suppress both the broad emission lines and X-rays in the Einstein and HEAO-1 energy bands. The observed properties of such Compton thick active galaxies are expected to be similar to those of Seyfert 2 nuclei. The implications for polarization and variability are also discussed.
Measured descent: a new embedding method for finite metrics

We devise a new embedding technique, which we call measured descent, based on decomposing a metric space locally, at varying speeds, according to the density of some probability measure. This provides a refined and unified framework for the two primary methods of constructing Frechet embeddings for finite metrics, due to Bourgain (1985) and Rao (1999). We prove that any n-point metric space (X, d) embeds in Hilbert space with distortion $$O{\left( {{\sqrt {\alpha _{X} \cdot \log n} }} \right)},$$ where α X is a geometric estimate on the decomposability of X. As an immediate corollary, we obtain an $$O{\left( {{\sqrt {(\log \lambda _{X} )\log n} }} \right)}$$ distortion embedding, where λ X is the doubling constant of X. Since λ X ≤ n, this result recovers Bourgain’s theorem, but when the metric X is, in a sense, “low-dimensional,” improved bounds are achieved. Our embeddings are volume-respecting for subsets of arbitrary size. One consequence is the existence of (k, O(log n)) volume-respecting embeddings for all 1 ≤ k ≤ n, which is the best possible, and answers positively a question posed by U. Feige. Our techniques are also used to answer positively a question of Y. Rabinovich, showing that any weighted n-point planar graph embeds in $${\ell }^{{O(\log n)}}_{\infty } $$ with O(1) distortion. The O(log n) bound on the dimension is optimal, and improves upon the previously known bound of O((log n)2).
Multi-state discrimination below the quantum noise limit at the single-photon level

Measurements approaching the ultimate quantum limits of sensitivity are central in quantum information processing, quantum metrology, and communication. Quantum measurements to discriminate multiple states at the single-photon level are essential for optimizing information transfer in low-power optical communications and quantum communications, and can enhance the capabilities of many quantum information protocols. Here, we theoretically investigate and experimentally demonstrate the discrimination of multiple coherent states of light with sensitivities surpassing the quantum noise limit (QNL) at the single-photon level under realistic conditions of loss and noise based on strategies implementing globally-optimized adaptive measurements with single photon counting and displacement operations. These discrimination strategies can provide realistic advantages to enhance information transfer at low powers, and are compatible with photon number resolving detection, which provides robustness at high powers, thus allowing for surpassing the QNL at arbitrary input power levels under realistic conditions. Light has intrinsic quantum noise, which limits how well we can measure it, especially at low powers, and bounds how much information we can communicate. A team led by F. Elohim Becerra at the University of New Mexico demonstrated optimized measurements for light pulses with different phases at low powers, such as those used in coherent optical communication. These optimized measurements can surpass the ultimate sensitivity limits of ideal conventional detectors, even in the presence of loss and noise encountered in realistic situations. The measurements are based on combining the input pulse with a reference field, and counting single photons in a fraction of the pulse. By analyzing the detection outcome, the reference field can be optimized to enhance the measurement’s sensitivity. Optimized measurements at low powers may lead to more-efficient optical communication in realistic environments.
Nuclear mass measurements with radioactive ion beams

Nuclear masses are the most fundamental of all nuclear properties, yet they can provide a wealth of knowledge, including information on astrophysical sites, constraints on existing theory, and fund...
Electrode reactions in slowly relaxing media

Standard models of reaction kinetics in condensed materials rely on the Boltzmann-Gibbs distribution for the population of reactants at the top of the free energy barrier separating them from the products. While energy dissipation and quantum effects at the barrier top can potentially affect the transmission coefficient entering the rate pre-exponential factor, much stronger dynamical effects on the reaction barrier are caused by the breakdown of ergodicity for populating the reaction barrier (violation of the Boltzmann-Gibbs statistics). When the spectrum of medium modes coupled to the reaction coordinate includes fluctuations slower than the reaction rate, such nuclear motions dynamically freeze on the reaction time scale and do not contribute to the activation barrier. Here we consider the consequences of this scenario for electrode reactions in slowly relaxing media. Changing the electrode overpotential speeds the electrode electron transfer up, potentially cutting through the spectrum of nuclear modes coupled to the reaction coordinate. The reorganization energy of electrochemical electron transfer becomes a function of the electrode overpotential, switching between the thermodynamic value at low rates to the nonergodic limit at higher rates. The sharpness of this transition depends on the relaxation spectrum of the medium. The reorganization energy experiences a sudden drop with increasing overpotential for a medium with a Debye relaxation but becomes a much shallower function of the overpotential for media with stretched exponential dynamics. The latter scenario characterizes the electron transfer in ionic liquids. The analysis of electrode reactions in room-temperature ionic liquids shows that the magnitude of the free energy of nuclear solvation is significantly below its thermodynamic limit. This result applies to reaction times faster than microseconds and is currently limited by the available dielectric relaxation data.
Euler Characteristics of Crepant Resolutions of Weierstrass Models

Based on an identity of Jacobi, we prove a simple formula that computes the pushforward of analytic functions of the exceptional divisor of a blowup of a projective variety along a smooth complete intersection with normal crossing. We use this pushforward formula to derive generating functions for Euler characteristics of crepant resolutions of singular Weierstrass models given by Tate’s algorithm. Since the Euler characteristic depends only on the sequence of blowups and not on the Kodaira fiber itself, several distinct Tate models have the same Euler characteristic. In the case of elliptic Calabi–Yau threefolds, using the Shioda–Tate–Wazir theorem, we also compute the Hodge numbers. For elliptically fibered Calabi–Yau fourfolds, our results also prove a conjecture of Blumenhagen, Grimm, Jurke, and Weigand based on F-theory/heterotic string duality.
Rashba realization: Raman with RF.

We theoretically explore a Rashba spin–orbit coupling scheme which operates entirely in the absolute ground state manifold of an alkali atom, thereby minimizing all inelastic processes. An energy gap between ground eigenstates of the proposed coupling can be continuously opened or closed by modifying laser polarizations. Our technique uses far-detuned ‘Raman’ laser coupling to create the Rashba potential, which has the benefit of low spontaneous emission rates. At these detunings, the Raman matrix elements that link mF magnetic sublevel quantum numbers separated by two are also suppressed. These matrix elements are necessary to produce the Rashba Hamiltonian within a single total angular momentum f manifold. However, the far-detuned Raman couplings can link the three XYZ states familiar to quantum chemistry, which possess the necessary connectivity to realize the Rashba potential. We show that these XYZ states are essentially the hyperfine spin eigenstates of 87Rb dressed by a strong radio-frequency magnetic field.
The Eigenvalue Distribution of Discrete Periodic Time-Frequency Limiting Operators

Bandlimiting and timelimiting operators play a fundamental role in analyzing bandlimited signals that are approximately timelimited (or vice versa). In this letter, we consider a time-frequency (in the discrete Fourier transform (DFT) domain) limiting operator whose eigenvectors are known as the periodic discrete prolate spheroidal sequences . We establish new nonasymptotic results on the eigenvalue distribution of this operator. As a byproduct, we also characterize the eigenvalue distribution of a set of submatrices of the DFT matrix, which is of independent interest.
Thermal expansion coefficients of high thermal conducting BAs and BP materials

Recently reported very high thermal conductivities in cubic boron arsenide (BAs) and boron phosphide (BP) crystals could potentially provide a revolutionary solution in the thermal management of high power density devices. To fully facilitate such an application, the compatible coefficient of thermal expansion (CTE) between the heat spreader and the device substrate, in order to minimize the thermal stress, needs to be considered. Here, we report our experimental CTE studies of BAs and BP in the temperature range from 100 K to 1150 K, through a combination of X-ray single crystal diffraction and neutron powder diffraction. We demonstrated that the room temperature CTEs, 3.6 ± 0.15 × 10−6/K for BAs and 3.2 ± 0.2 × 10−6/K for BP, are more compatible with most of the semiconductors including Si and GaAs, in comparison with diamond, and thus could be better candidates for the future heat spreader materials in power electronic devices.
Exploring quantum dynamics in an open many-body system: transition to superradiance

We study the dynamics of a complex open quantum many-body system. The coupling to external degrees of freedom can be viewed as a coupling to a radiation field, to continuum states or to a measuring apparatus. This perturbation is treated in terms of an effective non-Hermitian Hamiltonian. The influence of such coupling on the properties of the many-body dynamics is discussed, with emphasis on new effects related to dynamical segregation of fast and slow decays and the phase transition to Dicke superradiance. Relations to quantum optics, the continuum shell model, the theory of measurement, quantum chaos, percolation theory and quantum reactions are stressed.
Generalized Hypergraph Matching via Iterated Packing and Local Ratio

In \(k\)-hypergraph matching, we are given a collection of sets of size at most \(k\), each with an associated weight, and we seek a maximum-weight subcollection whose sets are pairwise disjoint. More generally, in \(k\)-hypergraph \(b\)-matching, instead of disjointness we require that every element appears in at most \(b\) sets of the subcollection. Our main result is a linear-programming based \((k-1+\tfrac{1}{k})\)-approximation algorithm for \(k\)-hypergraph \(b\)-matching. This settles the integrality gap when \(k\) is one more than a prime power, since it matches a previously-known lower bound. When the hypergraph is bipartite, we are able to improve the approximation ratio to \(k-1\), which is also best possible relative to the natural LP. These results are obtained using a more careful application of the iterated packing method.
On compact hyperbolic manifolds of Euler characteristic two

We prove that for n>4 there is no compact arithmetic hyperbolic n–manifold whose Euler characteristic has absolute value equal to 2. In particular, this shows the nonexistence of arithmetically defined hyperbolic rational homology n–spheres with n even and different than 4.
Spectro-Thermometry Of M Dwarfs And Their Candidate Planets: Too Hot, Too Cool, Or Just Right?

We use moderate-resolution spectra of nearby late K and M dwarf stars with parallaxes and interferometrically determined radii to refine their effective temperatures, luminosities, and metallicities. We use these revised values to calibrate spectroscopic techniques to infer the fundamental parameters of more distant late-type dwarf stars. We demonstrate that, after masking out poorly modeled regions, the newest version of the PHOENIX atmosphere models accurately reproduce temperatures derived bolometrically. We apply methods to late-type hosts of transiting planet candidates in the Kepler field, and calculate effective temperature, radius, mass, and luminosity with typical errors of 57?K, 7%, 11%, and 13%, respectively. We find systematic offsets between our values and those from previous analyses of the same stars, which we attribute to differences in atmospheric models utilized for each study. We investigate which of the planets in this sample are likely to orbit in the circumstellar habitable zone. We determine that four candidate planets (KOI 854.01, 1298.02, 1686.01, and 2992.01) are inside of or within 1? of a conservative definition of the habitable zone, but that several planets identified by previous analyses are not (e.g., KOI 1422.02 and KOI 2626.01). Only one of the four habitable-zone planets is Earth sized, suggesting a downward revision in the occurrence of such planets around M dwarfs. These findings highlight the importance of measuring accurate stellar parameters when deriving parameters of their orbiting planets.
A Third Hot White Dwarf Companion Detected by Kepler

United States. National Aeronautics and Space Administration (NASA Origins of Solar Systems grant no. NNX09AD36G)
Pairing insights in iron-based superconductors from scanning tunneling microscopy

Abstract Scanning tunneling microscopy (STM) has made tremendous progress in the study and understanding of both classical and unconventional superconductors. This has motivated a rapidly growing effort to apply the same techniques to the iron-based high-Tc superconductors since their discovery in 2008. Five years have brought exciting advances in imaging and spectroscopic investigation of this new class of materials. In this review, we focus on several recent STM contributions to the identification of the gap symmetry and pairing glue. We highlight the unique capabilities and challenges still ahead for STM studies of iron-based superconductors.
Dynamic and Versatile Humanoid Walking via Embedding 3D Actuated SLIP Model With Hybrid LIP Based Stepping

In this letter, we propose an efficient approach to generate dynamic and versatile humanoid walking with non-constant center of mass (COM) height. We exploit the benefits of using reduced order models (ROMs) and stepping control to generate dynamic and versatile walking motion. Specifically, we apply the stepping controller based on the Hybrid Linear Inverted Pendulum Model (H-LIP) to perturb a periodic walking motion of a 3D actuated Spring Loaded Inverted Pendulum (3D-aSLIP), which yields versatile walking behaviors of the 3D-aSLIP, including various 3D periodic walking, fixed location tracking, and global trajectory tracking. The 3D-aSLIP walking is then embedded on the fully-actuated humanoid via the task space control on the COM dynamics and ground reaction forces. The proposed approach is realized on the robot model of Atlas in simulation, wherein versatile dynamic motions are generated.
Infrared Candidates for the Intense Galactic X-Ray Source GX 17+2

We present new astrometric solutions and infrared Hubble Space Telescope observations of GX 17+2 (X1813-140), one of the brightest X-ray sources on the celestial sphere. Despite 30 years of intensive study and the existence of a strong radio counterpart with a subarcsecond position, the object remains optically unidentified. The observed X-ray characteristics strongly suggest that it is a so-called Z source, the rare but important category that includes Sco X-1 and Cyg X-2. Use of the USNO-A2.0 catalog enables us to measure the position of optical and infrared objects near the radio source to subarcsecond precision within the International Celestial Reference Frame for direct comparison with the radio position, which we also recompute using modern calibrators. With high confidence we eliminate the V ~ 17.5 star NP Ser, often listed as the probable optical counterpart of the X-ray source, as a candidate. Our HST NICMOS observations show two faint objects within our 05 radius 90% confidence error circle. Even the brighter of the two, star A, is far fainter than expected (H ≈ 19.8), given multiple estimates of the extinction in this field and our previous understanding of Z sources, but it becomes the best candidate for the counterpart of GX 17+2. The probability of a chance coincidence of an unrelated faint object on the radio position is high. However, if the true counterpart is not star A, it is fainter still, and our conclusion that the optical counterpart is surprisingly underluminous is but strengthened.
Trisecting non-Lagrangian theories

We propose a way to define and compute invariants of general smooth 4-manifolds based on topological twists of non-Lagrangian 4d N=2 and N=3 theories in which the problem is reduced to a fairly standard computation in topological A-model, albeit with rather unusual targets, such as compact and non-compact Gepner models, asymmetric orbifolds, N=(2,2) linear dilaton theories, “self-mirror” geometries, varieties with complex multiplication, etc.
Driven Nonlinear Dynamics of Two Coupled Exchange-Only Qubits

Realization of quantum computing requires not only qubits that are robust against noise but also control over the crosstalk (entanglement) between them. Following the very recent experimental realization of quantum-dot-based ``exchange'' qubits, theorists propose a practically feasible method for entangling two such qubits in a controllable way.
A computational workflow for designing silicon donor qubits

Developing devices that can reliably and accurately demonstrate the principles of superposition and entanglement is an on-going challenge for the quantum computing community. Modeling and simulation offer attractive means of testing early device designs and establishing expectations for operational performance. However, the complex integrated material systems required by quantum device designs are not captured by any single existing computational modeling method. We examine the development and analysis of a multi-staged computational workflow that can be used to design and characterize silicon donor qubit systems with modeling and simulation. Our approach integrates quantum chemistry calculations with electrostatic field solvers to perform detailed simulations of a phosphorus dopant in silicon. We show how atomistic details can be synthesized into an operational model for the logical gates that define quantum computation in this particular technology. The resulting computational workflow realizes a design tool for silicon donor qubits that can help verify and validate current and near-term experimental devices.
New solution approaches for the maximum-reliability stochastic network interdiction problem

We investigate methods to solve the maximum-reliability stochastic network interdiction problem (SNIP). In this problem, a defender interdicts arcs on a directed graph to minimize an attacker’s probability of undetected traversal through the network. The attacker’s origin and destination are unknown to the defender and assumed to be random. SNIP can be formulated as a stochastic mixed-integer program via a deterministic equivalent formulation (DEF). As the size of this DEF makes it impractical for solving large instances, current approaches to solving SNIP rely on modifications of Benders decomposition. We present two new approaches to solve SNIP. First, we introduce a new DEF that is significantly more compact than the standard DEF. Second, we propose a new path-based formulation of SNIP. The number of constraints required to define this formulation grows exponentially with the size of the network, but the model can be solved via delayed constraint generation. We present valid inequalities for this path-based formulation which are dependent on the structure of the interdicted arc probabilities. We propose a branch-and-cut (BC) algorithm to solve this new SNIP formulation. Computational results demonstrate that directly solving the more compact SNIP formulation and this BC algorithm both provide an improvement over a state-of-the-art implementation of Benders decomposition for this problem.
Wrapping Liquids, Solids, and Gases in Thin Sheets

Many objects in nature and industry are wrapped in a thin sheet to enhance their chemical, mechanical, or optical properties. Similarly, there are a variety of methods for wrapping, from pressing a...
The Relativistic Euler Equations: Remarkable Null Structures and Regularity Properties

We derive a new formulation of the relativistic Euler equations that exhibits remarkable properties. This new formulation consists of a coupled system of geometric wave, transport, and transport-div-curl equations, sourced by nonlinearities that are null forms relative to the acoustical metric. Our new formulation is well-suited for various applications, in particular, for the study of stable shock formation, as it is surveyed in the paper. Moreover, using the new formulation presented here, we establish a local well-posedness result showing that the vorticity and the entropy of the fluid are one degree more differentiable compared to the regularity guaranteed by standard estimates (assuming that the initial data enjoy the extra differentiability). This gain in regularity is essential for the study of shock formation without symmetry assumptions. Our results hold for an arbitrary equation of state, not necessarily of barotropic type.
Interpretation of Infrared Vibration-rotation Spectra of Interstellar and Circumstellar Molecules

Infrared vibration-rotation lines can be valuable probes of interstellar and circumstellar molecules, especially symmetric molecules, which have no pure rotational transitions. But most such observations have been interpreted with an isothermal absorbing slab model, which leaves out important radiative transfer and molecular excitation effects. A more realistic non-LTE and non-isothermal radiative transfer model has been constructed. The results of this model are in much better agreement with the observations, including cases where lines in one branch of a vibration-rotation band are in absorption and another in emission. In general, conclusions based on the isothermal absorbing slab model can be very misleading, but the assumption of LTE may not lead to such large errors, particularly if the radiation field temperature is close to the gas temperature.
VACUUM STRUCTURE AND DARK ENERGY

We consider that the universe is trapped in an excited vacuum state and the resulting excitation energy provides the observed dark energy. We explore the conditions under which this situation can arise from physics already known. Considering the example of how macroscopic quantum electrodynamic fields alter the vacuum structure, we find that the energy scale 1 meV–1 eV is particularly interesting. We discuss how dark energy of this form is accessible to laboratory experiments.
Matrix ensembles with global symmetries and 't Hooft anomalies from 2d gauge theory

The Hilbert space of a quantum system with internal global symmetry G decomposes into sectors labelled by irreducible representations of G. If the system is chaotic, the energies in each sector should separately resemble ordinary random matrix theory. We show that such “sector-wise” random matrix ensembles arise as the boundary dual of two- dimensional gravity with a G gauge field in the bulk. Within each sector, the eigenvalue density is enhanced by a nontrivial factor of the dimension of the representation, and the ground state energy is determined by the quadratic Casimir. We study the consequences of ’t Hooft anomalies in the matrix ensembles, which are incorporated by adding specific topological terms to the gauge theory action. The effect is to introduce projective representations into the decomposition of the Hilbert space. Finally, we consider ensembles with G symmetry and time reversal symmetry, and analyze a simple case of a mixed anomaly between time reversal and an internal ℤ2 symmetry.
Bounded gaps between primes in multidimensional Hecke equidistribution problems

Using Duke's large sieve inequality for Hecke Gr{\"o}ssencharaktere and the new sieve methods of Maynard and Tao, we prove a general result on gaps between primes in the context of multidimensional Hecke equidistribution. As an application, for any fixed $0<\epsilon<\frac{1}{2}$, we prove the existence of infinitely many bounded gaps between primes of the form $p=a^2+b^2$ such that $|a|<\epsilon\sqrt{p}$. Furthermore, for certain diagonal curves $\mathcal{C}:ax^{\alpha}+by^{\beta}=c$, we obtain infinitely many bounded gaps between the primes $p$ such that $|p+1-\#\mathcal{C}(\mathbb{F}_p)|<\epsilon\sqrt{p}$.
On the Assembly History of Early-Type Galaxies in the Hubble Deep Field-North* **

We present deep Keck spectroscopy for a sample of I814 < 22.5 field early-type galaxies selected morphologically in the redshift range 0.56 ≤ z ≤ 1.02 in the Hubble Deep Field-North (HDF-N). Using velocity dispersions determined from the Keck spectra in conjunction with structural parameters measured from the deep WFPC2 images, we study the evolution of the M/LB ratio and the fundamental plane with redshift. For the majority of galaxies, the trends observed are very similar to those determined earlier for rich clusters. The systematic offset between HDF-N galaxies and cluster galaxies is Δ ln M/LB = -0.14 ± 0.13, corresponding to an age difference of only 16% ± 15% at = 0.88. However, we find enhanced Hδ absorption with an equivalent width of 4.0 A in the mean spectrum of the 10 galaxies, indicating the presence of young stars. We infer that the galaxies have composite stellar populations, consisting of a low-mass young component in addition to a dominating old component. Since the bulk of the stellar mass must have formed at z 2, our results argue against formation scenarios involving major mergers of gas-rich disk systems at 1 z 1.5, and we conclude that z 1 early-type galaxies were assembled either at higher redshift or in mergers involving little gas. The ubiquitous enhanced Balmer lines and the presence of tidal features in two of the galaxies lend some support to the latter hypothesis. The main uncertainty in the analysis is the small sample; larger samples of early-type galaxies are needed to study in detail the interplay between the evolution of their stellar populations and morphology.
Magnonic Band Structure Established by Chiral Spin-Density Waves in Thin-Film Ferromagnets

Recent theoretical studies have demonstrated the possibility to excite and sustain noncollinear magnetization states in ferromagnetic nanowires. The resulting state is referred to as a spin-density wave (SDW). SDWs can be interpreted as hydrodynamic states with a constant fluid density and fluid velocity in systems with easy-plane anisotropy. Here, we consider the effect of the nonlocal dipole field arising from the finite thickness of magnetic thin films on the spatial profile of the SDW and on the associated magnon dispersion. Utilizing a hydrodynamic formulation of the Larmor torque equation, it is found that the nonlocal dipole field modulates the fluid velocity. Such a modulation induces a magnonic band structure unlike the typical dispersion relation for magnons on uniform magnetization. The analytical results are validated by micromagnetic simulations. Band gaps on the order of gigahertz are numerically observed to depend on the SDW fluid velocity and film thickness for realistic material parameters. The presented results suggest that SDWs can find applications as reconfigurable magnonic crystals.
DeepCorrect: Correcting DNN Models Against Image Distortions

In recent years, the widespread use of deep neural networks (DNNs) has facilitated great improvements in performance for computer vision tasks like image classification and object recognition. In most realistic computer vision applications, an input image undergoes some form of image distortion such as blur and additive noise during image acquisition or transmission. Deep networks trained on pristine images perform poorly when tested on such distortions. In this paper, we evaluate the effect of image distortions like Gaussian blur and additive noise on the activations of pre-trained convolutional filters. We propose a metric to identify the most noise susceptible convolutional filters and rank them in order of the highest gain in classification accuracy upon correction. In our proposed approach called DeepCorrect , we apply small stacks of convolutional layers with residual connections at the output of these ranked filters and train them to correct the worst distortion affected filter activations, while leaving the rest of the pre-trained filter outputs in the network unchanged. Performance results show that applying DeepCorrect models for common vision tasks like image classification (ImageNet), object recognition (Caltech-101, Caltech-256), and scene classification (SUN-397), significantly improves the robustness of DNNs against distorted images and outperforms other alternative approaches.
Financial Crime & Fraud Detection Using Graph Computing: Application Considerations & Outlook

In recent years, the unprecedented growth in digital payments fueled consequential changes in fraud and financial crimes. In this new landscape, traditional fraud detection approaches such as rule-based engines have largely become ineffective. AI and machine learning solutions using graph computing principles have gained significant interest. Graph neural networks and emerging adaptive solutions provide compelling opportunities for the future of fraud and financial crime detection. However, implementing the graph-based solutions in financial transaction processing systems has brought numerous obstacles and application considerations to light. In this paper, we overview the latest trends in the financial crimes landscape and discuss the implementation difficulties current and emerging graph solutions face. We argue that the application demands and implementation challenges provide key insights in developing effective solutions.
Long-Term Regularity of the Periodic Euler-Poisson System for Electrons in 2D

We study a basic plasma physics model—the one-fluid Euler–Poisson system on the square torus, in which a compressible electron fluid flows under its own electrostatic field. In this paper we prove long-term regularity of periodic solutions of this system in 2 spatial dimensions with small data. Our main conclusion is that on a square torus of side length R, if the initial data is sufficiently close to a constant solution, then the solution is wellposed for a time at least $${R/(\epsilon^{2}({\rm log} R)^{O(1)})}$$ , where $${\epsilon}$$ is the size of the initial data.
THE DEDICATED MONITOR OF EXOTRANSITS (DEMONEX): SEVEN TRANSITS OF XO-4b

The DEdicated MONitor of EXotransits (DEMONEX) was a 20-inch robotic and automated telescope to monitor bright stars hosting transiting exoplanets to discover new planets and improve constraints on the properties of known transiting planetary systems. We present results for the misaligned hot Jupiter XO-4b containing seven new transits from the DEMONEX telescope, including three full and four partial transits. We combine these data with archival light curves and archival radial velocity measurements to derive the host star mass and radius , the planet mass and radius , and a refined ephemeris of days and . We include archival Rossiter–McLaughlin measurements of XO-4 to infer the stellar spin–planetary orbit alignment of degrees. We test the effects of including various detrend parameters, theoretical and empirical mass–radius relations, and Rossiter–McLaughlin models. We infer that detrending against CCD position and time or airmass can improve data quality but can have significant effects on the inferred values of many parameters—most significantly and the observed central transit times TC. In the case of we find that the systematic uncertainty due to detrending can be three times that of the quoted statistical uncertainties. The choice of mass–radius relation has little effect on our inferred values of the system parameters. The choice of Rossiter–McLaughlin models can have significant effects on the inferred values of and the stellar spin–planet orbit angle λ.
Turbulent spectra in the solar wind plasma

Observations of interstellar scintillations at radio wavelengths reveal a Kolmogorov-like scaling of' the electron density spectrum with a spectral slope of -5/3 over six decades in wavenumber space. A similar turbulent density spectrum in the solar wind plasma has been reported. The energy transfer process in the magnetized solar wind plasma over such extended length scales remains an unresolved paradox of modern turbulence theories, raising the especially intriguing question of how a compressible magnetized solar wind exhibits a turbulent spectrum that is a characteristic of an incompressible hydrodynamic fluid. To address these questions, we have undertaken three-dimensional time-dependent numerical simulations of a compressible magnetohydrodynamic fluid describing super-Alfvenic, supersonic and strongly magnetized plasma. It is shown that the observed Kolmogorov-like (-5/3) spectrum can develop in the solar wind plasma by supersonic plasma motions that dissipate into highly subsonic motion that passively convect density fluctuations.
Cohomology of the Universal Smooth Cubic Surface

We compute the rational cohomology of the universal family of smooth cubic surfaces using Vassiliev's method of simplicial resolution. Modulo embedding, the universal family has cohomology isomorphic to that of $\mathbb{P}^2$. A consequence of our theorem is that over the finite field $\mathbb{F}_q$, away from finitely many characteristics, the average number of points on a smooth cubic surface is $q^2 + q + 1$.
Factoring the Strong CP Problem

We present a new mechanism to solve the strong CP problem using N ≥ 2 axions, each dynamically relaxing part of the θ parameter. At high energies M ≫ ΛQCD the SU(3)c group becomes the diagonal subgroup of an SU(3)N gauge group, and the non-perturbative effects in each individual SU(3) factor generate a potential for the corresponding axion. The vacuum is naturally aligned to ensure $$ \overline{\theta} = 0 $$ at low energies, and the masses of these axions can be much larger than for the standard QCD axion. This mechanism avoids the introduction of a discrete Z2 symmetry and associated ‘mirror’ copies of the SM fermions, and also avoids the introduction and stabilization of new light colored states to modify the running of the QCD gauge coupling found in other heavy axion models. This strengthens the motivation for axion-like particles solving the strong CP problem at points beyond the standard QCD axion curve in the (ma, fa) plane.
Intrinsic ergodicity via obstruction entropies

Bowen showed that a continuous expansive map with specification has a unique measure of maximal entropy. We show that the conclusion remains true under weaker non-uniform versions of these hypotheses. To this end, we introduce the notions of obstructions to expansivity and specification, and show that if the entropy of such obstructions is smaller than the topological entropy of the map, then there is a unique measure of maximal entropy.
Regularized rank-based estimation of high-dimensional nonparanormal graphical models

A sparse precision matrix can be directly translated into a sparse Gaussian graphical model under the assumption that the data follow a joint normal distribution. This neat property makes high-dimensional precision matrix estimation very appealing in many applications. However, in practice we often face nonnormal data, and variable transformation is often used to achieve normality. In this paper we consider the nonparanormal model that assumes that the variables follow a joint normal distribution after a set of unknown monotone transformations. The nonparanormal model is much more flexible than the normal model while retaining the good interpretability of the latter in that each zero entry in the sparse precision matrix of the nonparanormal model corresponds to a pair of conditionally independent variables. In this paper we show that the nonparanormal graphical model can be efficiently estimated by using a rank-based estimation scheme which does not require estimating these unknown transformation functions. In particular, we study the rank-based graphical lasso, the rank-based neighborhood Dantzig selector and the rank-based CLIME. We establish their theoretical properties in the setting where the dimension is nearly exponentially large relative to the sample size. It is shown that the proposed rank-based estimators work as well as their oracle counterparts defined with the oracle data. Furthermore, the theory motivates us to consider the adaptive version of the rank-based neighborhood Dantzig selector and the rank-based CLIME that are shown to enjoy graphical model selection consistency without assuming the irrepresentable condition for the oracle and rank-based graphical lasso. Simulated and real data are used to demonstrate the finite performance of the rank-based estimators.