cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterizing filamentary magnetic structures in counter-streaming plasmas by Fourier analysis of proton images

Proton imaging is a powerful tool for probing electromagnetic fields in a plasma, providing a path-integrated map of the field topology. However, in cases where the field structure is highly inhomogeneous, inferring spatial properties of the underlying field from proton images can be difficult. This problem is exemplified by recent experiments, which used proton imaging to probe the filamentary magnetic field structures produced by the Weibel instability in collisionless counterstreaming plasmas. In this paper, we perform analytical and numerical analyses of proton images of systems containing many magnetic filaments. We find that, in general, the features observed on proton images do not directly correspond to the spacing between magnetic filaments (the magnetic wavelength) as has previously been assumed and that they instead correspond to the filament size. We demonstrate this result by Fourier analysis of synthetic proton images for many randomized configurations of magnetic filaments. Our results help guide the interpretation of experimental proton images of filamentary magnetic structures in plasmas.
UV-C tower for point-of-care decontamination of filtering facepiece respirators.

Background Filtering facepiece respirators (FFR) are critical for protecting essential personnel and limiting the spread of disease. Due to the current COVID-19 pandemic, FFR supplies are dwindling in many health systems, necessitating re-use of potentially contaminated FFR. Multiple decontamination solutions have been developed to meet this pressing need, including systems designed for bulk decontamination of FFR using vaporous hydrogen peroxide or ultraviolet-C (UV-C) radiation. However, the large scale on which these devices operate may not be logistically practical for small or rural health care settings or for ad hoc use at points-of-care. Methods Here, we present the Synchronous UV Decontamination System, a novel device for rapidly deployable, point-of-care decontamination using UV-C germicidal irradiation. We designed a compact, easy-to-use device capable of delivering over 2 J cm2 of UV-C radiation in one minute. Results We experimentally tested Synchronous UV Decontamination System' microbicidal capacity and found that it eliminates near all virus from the surface of tested FFRs, with less efficacy against pathogens embedded in the inner layers of the masks. Conclusions This short decontamination time should enable care-providers to incorporate decontamination of FFR into a normal donning and doffing routine following patient encounters.
DIMENSIONAL CONTINUATION WITHOUT PERTURBATION THEORY

A formula is proposed for continuing physical correlation functions to noninteger numbers of dimensions, expressing them as infinite weighted sums over the same correlation functions in arbitrary integer dimensions. The formula is motivated by studying the strong coupling expansion, but the end result makes no reference to any perturbation theory. It is shown that the formula leads to the correct dimension dependence in weak coupling perturbation theory at one-loop.
Operad bimodules and composition products on André–Quillen filtrations of algebras

If O is a reduced operad in a symmetric monoidal category of spectra (S–modules), an O–algebra I can be viewed as analogous to the augmentation ideal of an augmented algebra. From the literature on topological Andre–Quillen homology, one can see that such an I admits a canonical (and homotopically meaningful) decreasing O–algebra filtration I← ∼I1 ← I2 ← I3 ←⋯ satisfying various nice properties analogous to powers of an ideal in a ring. We more fully develop such constructions in a manner allowing for more flexibility and revealing new structure. With R a commutative S–algebra, an O–bimodule M defines an endofunctor of the category of O–algebras in R–modules by sending such an O–algebra I to M ∘OI. We explore the use of the bar construction as a derived version of this. Letting M run through a decreasing O–bimodule filtration of O itself then yields the augmentation ideal filtration as above. The composition structure of the operad then induces pairings among these bimodules, which in turn induce natural transformations (Ii)j → Iij, fitting nicely with previously studied structure. As a formal consequence, an O–algebra map I → Jd induces compatible maps In → Jdn for all n. This is an essential tool in the first author’s study of Hurewicz maps for infinite loop spaces, and its utility is illustrated here with a lifting theorem.
Volume stabilization and the origin of the inflaton shift symmetry in string theory

One of the main problems of inflation in string theory is finding models with a flat potential while simultaneously stabilizing the volume of the compactified space. This can be achieved in theories where the potential has (an approximate) shift symmetry in the inflaton direction. We will identify a class of models where the shift symmetry uniquely follows from the underlying mathematical structure of the theory. It is related to the symmetry properties of the corresponding coset space and the period matrix of special geometry, which shows how the gauge coupling depends on the volume and the position of the branes. In particular, for type IIB string theory on K3 × T2/2 with D3 or D7 moduli belonging to vector multiplets, the shift symmetry is a part of SO(2,2+n) symmetry of the coset space (SU(1,1)/U(1))×(SO(2,2+n)/(SO(2)×SO(2+n))). The absence of a prepotential, specific for the stringy version of supergravity, plays a prominent role in this construction, which may provide a viable mechanism for the accelerated expansion and inflation in the early universe.
Separation scaling for viscous vortex reconnection

Reconnection plays a significant role in the dynamics of plasmas, polymers and macromolecules, as well as in numerous laminar and turbulent flow phenomena in both classical and quantum fluids. Extensive studies in quantum vortex reconnection show that the minimum separation distance between the two interacting viscous vortices surprisingly also follows the 1/2-power scaling for both pre- and post-reconnection events. The prefactors in this 1/2-power law are found to depend not only on the initial configuration but also on the vortex Reynolds number (or viscosity). Our finding in viscous reconnection, complementing numerous works on quantum vortex reconnection, suggests that there is indeed a universal route for reconnection – an essential result for understanding the various facets of the vortex reconnection phenomena and their potential modelling, as well as possibly explaining turbulence cascade physics.
Testing general relativity with the Event Horizon Telescope

The Event Horizon Telescope is a millimeter VLBI array that is taking the first horizon-scale pictures of the black hole in the center of the M87 galaxy and, in the near future, of the one in the center of the Milky Way. Measurements of the shape and size of the shadows cast by the black holes on the surrounding emission can test the cosmic censorship conjecture and the no-hair theorem and may find evidence for classical effects of the quantum structure of black holes. Observations of coherent structures in the accretion flows may lead to accurate measurements of the spins of the black holes and of other properties of their spacetimes. For Sgr A*, the black hole in the center of the Milky Way, measurements of the precession of stellar orbits and timing monitoring of orbiting pulsars offer complementary avenues to the gravitational tests with the Event Horizon Telescope.
Model of the dynamics of an interface between a smectic phase and an isotropic phase of different density

Soft modulated phases are known to undergo complex morphological transitions through layer remodeling. A quasi-incompressible phase-field model for a layered phase in contact with an isotropic fluid is derived, which couples the layering order parameter to velocity and also to a varying density field function of the order parameter's amplitude. Evolution and fluid flows on distorted smectics and focal conic defects are investigated through the proposed model.
Shallow water modeling of rolling pad instability in liquid metal batteries

Magnetohydrodynamically induced interface instability in liquid metal batteries is analyzed. The batteries are represented by a simplified system in the form of a rectangular cell, in which strong vertical electric current flows through three horizontal layers: the layer of a heavy metal at the bottom, the layer of a light metal at the top, and the layer of electrolyte in the middle. A new two-dimensional nonlinear model based on the conservative shallow water approximation is derived and utilized in a numerical study. It is found that in the case of small density difference between the electrolyte and one of the metals, the instability closely resembles the rolling pad instability observed earlier in the aluminum reduction cells. When the two electrolyte-metal density differences are comparable, the dynamics of unstable systems is more complex and characterized by interaction between two nearly synchronized or nearly anti-synchronized interfacial waves.
Persistence of physics and engineering students via peer mentoring, active learning, and intentional advising

Albion College, a private, undergraduate-only, liberal arts college in Michigan, USA, has developed and implemented a low-cost peer-mentoring programme that blends personal and academic support to help students achieve academic success in the introductory courses required for the Physics Major or the Dual-Degree Program in Engineering. This enhanced mentoring programme provides much-needed assistance for undergraduate students to master introductory physics and mathematics coursework, to normalise the struggle of learning hard material, and to accept their identity as physics or engineering students (among other goals). Importantly, this programme has increased retention among entering science, technology, engineering and mathematics students at Albion College as they move through the introductory classes, as shown by a 20% increase in retention from first-semester to third-semester physics courses compared to years when this programme was not in place.
Quantum mechanics in noninertial reference frames: Violations of the nonrelativistic equivalence principle

Abstract In previous work we have developed a formulation of quantum mechanics in non-inertial reference frames. This formulation is grounded in a class of unitary cocycle representations of what we have called the Galilean line group, the generalization of the Galilei group that includes transformations amongst non-inertial reference frames. These representations show that in quantum mechanics, just as is the case in classical mechanics, the transformations to accelerating reference frames give rise to fictitious forces. A special feature of these previously constructed representations is that they all respect the non-relativistic equivalence principle, wherein the fictitious forces associated with linear acceleration can equivalently be described by gravitational forces. In this paper we exhibit a large class of cocycle representations of the Galilean line group that violate the equivalence principle. Nevertheless the classical mechanics analogue of these cocycle representations all respect the equivalence principle.
An exact local hybrid Monte Carlo algorithm for gauge theories

Abstract We introduce a new Monte Carlo method for pure gauge theories. It is not intended for use with dynamical fermions. It belongs to the class of Local Hybrid Monte Carlo (LHMC) algorithms, which make use of the locality of the action by updating individual sites or links by following a classical mechanics trajectory in fictitious time. We choose to update a one-parameter subgroup of the gauge field on each link of the lattice, and the classical trajectory can be found in closed form in terms of elliptic functions for this case. We show that this gives an overrelaxation algorithm with a tunable parameter which, unlike some previous methods, does not require the numerical integration of the equations of motion.
Bit threads and holographic entanglement

The Ryu-Takayanagi (RT) formula relates the entanglement entropy of a region in a holographic theory to the area of a corresponding bulk minimal surface. Using the max flow-min cut principle, a theorem from network theory, we rewrite the RT formula in a way that does not make reference to the minimal surface. Instead, we invoke the notion of a "flow", defined as a divergenceless norm-bounded vector field, or equivalently a set of Planck-thickness "bit threads". The entanglement entropy of a boundary region is given by the maximum flux out of it of any flow, or equivalently the maximum number of bit threads that can emanate from it. The threads thus represent entanglement between points on the boundary, and naturally implement the holographic principle. As we explain, this new picture clarifies several conceptual puzzles surrounding the RT formula. We give flow-based proofs of strong subadditivity and related properties; unlike the ones based on minimal surfaces, these proofs correspond in a transparent manner to the properties' information-theoretic meanings. We also briefly discuss certain technical advantages that the flows oer over minimal surfaces. In a mathematical appendix, we review the max flow-min cut theorem on networks and on Riemannian manifolds, and prove in the network case that the set of max flows varies Lipshitz continuously in the network parameters.
The Vertical Equilibrium of Molecular Gas in the Galactic Disk

We examine the vertical structure and equilibrium of the molecular gas layer in the galactic disk, measuring its scale height and velocity dispersion as a function of Galactic radius by modeling the CO emission at the tangent points. The model takes into account emission from a large path length along the line of sight, corresponding to an interval \Delta R ~ 200-400 pc; and is parametrized by the scale height of the gas, the centroid in z, the rotation velocity and the velocity dispersion. This model is then fit to the $^{12}CO$ survey of Knapp et al.(1985) to determine the best fit parameters. The reduced \chi^2 from fitting the models (considering only the photon statistics) range from 2 to 19. The main source of error is the `shot noise' due to the small number of clouds. Simulations using discrete molecular clouds are carried out to estimate the errors. The scale height of the molecular gas increases with radius. The velocity dispersion varies from ~ 2 km/s to 11 km/s with a typical uncertainty of ~3 km/s and shows a monotonic increase with galactic radius. The midplane mass density of the disk calculated from the scale-height and velocity dispersion is consistent with the local value \rho_0(R_0) of 0.2 \msun pc^{-3}.
Structure in the bipolar filtration of topologically slice knots

is the bipolar filtration of T . We show that T0=T1 has infinite rank, even modulo Alexander polynomial one knots. Recall that knots in T0 (a topologically slice 0‐ bipolar knot) necessarily have zero ‐, s ‐ and ‐invariants. Our invariants are detected using certain d ‐invariants associated to the 2‐fold branched covers. 57M25; 57N70
Excision for deformation K–theory of free products

Associated to a discrete group G , one has the topological category of finite dimensional (unitary) G–representations and (unitary) isomorphisms. Block sums provide this category with a permutative structure, and the associated K –theory spectrum is Carlsson’s deformation K –theory Kdef(G) . The goal of this paper is to examine the behavior of this functor on free products. Our main theorem shows the square of spectra associated to G ∗H (considered as an amalgamated product over the trivial group) is homotopy cartesian. The proof uses a general result regarding group completions of homotopy commutative topological monoids, which may be of some independent interest.
Excitations of the Myers-Perry Black Holes

We demonstrate separability of the dynamical equations for all p-form fluxes in the Myers-Perry-(A)dS geometry, extending the earlier results for electromagnetic field. In the physically important cases of p = (1–4), we explicitly write the ODEs governing the dynamics of separable solutions.
Ergodicity, Decisions, and Partial Information

In the simplest sequential decision problem for an ergodic stochastic process X, at each time n a decision u n is made as a function of past observations \(X_{0},\ldots,X_{n-1}\), and a loss l(u n , X n ) is incurred. In this setting, it is known that one may choose (under a mild integrability assumption) a decision strategy whose pathwise time-average loss is asymptotically smaller than that of any other strategy. The corresponding problem in the case of partial information proves to be much more delicate, however: if the process X is not observable, but decisions must be based on the observation of a different process Y, the existence of pathwise optimal strategies is not guaranteed. The aim of this paper is to exhibit connections between pathwise optimal strategies and notions from ergodic theory. The sequential decision problem is developed in the general setting of an ergodic dynamical system \((\varOmega,\mathcal{B},\mathbf{P},T)\) with partial information \(\mathcal{Y}\subseteq \mathcal{B}\). The existence of pathwise optimal strategies grounded in two basic properties: the conditional ergodic theory of the dynamical system, and the complexity of the loss function. When the loss function is not too complex, a general sufficient condition for the existence of pathwise optimal strategies is that the dynamical system is a conditional K-automorphism relative to the past observations \(\bigvee _{n\geq 0}T^{n}\mathcal{Y}\). If the conditional ergodicity assumption is strengthened, the complexity assumption can be weakened. Several examples demonstrate the interplay between complexity and ergodicity, which does not arise in the case of full information. Our results also yield a decision-theoretic characterization of weak mixing in ergodic theory, and establish pathwise optimality of ergodic nonlinear filters.
The dualizing spectrum II

One the early triumphs of surgery theory is the Browder–Casson–Sullivan–Wall theorem. It says that a Poincare embedding of PL manifolds in codimension at least three can always be lifted to a piecewise linear embedding. Thus the problem of finding manifold embeddings in these codimensions is reduced to a problem in homotopy theory. Even so, at least one golden era maven opined that the resulting homotopy theoretic problems seem “in some respects to be harder than the original geometrical problems” (see Wall [16, p 119]).
Pre-Defined Sparse Neural Networks With Hardware Acceleration

Neural networks have proven to be extremely powerful tools for modern artificial intelligence applications, but computational and storage complexity remain limiting factors. This paper presents two compatible contributions towards reducing the time, energy, computational, and storage complexities associated with multilayer perceptrons. Pre-defined sparsity is proposed to reduce the complexity during both training and inference, regardless of the implementation platform. Our results show that storage and computational complexity can be reduced by factors greater than 5X without significant performance loss. The second contribution is an architecture for hardware acceleration that is compatible with pre-defined sparsity. This architecture supports both training and inference modes and is flexible in the sense that it is not tied to a specific number of neurons. For example, this flexibility implies that various sized neural networks can be supported on various sized field programmable gate array (FPGA)s.
Bergman theory of certain generalized Hartogs triangles

The Bergman theory of domains $\{ |{z_{1} |^{\gamma}} < |{z_{2}} | < 1 \}$ in $\mathbb{C}^2$ is studied for certain values of $\gamma$, including all positive integers. For such $\gamma$, we obtain a closed form expression for the Bergman kernel, $\mathbb{B}_{\gamma}$. With these formulas, we make new observations relating to the Lu Qi-Keng problem and analyze the boundary behavior of $\mathbb{B}_{\gamma}(z,z)$.
The Art of Data Science

To flourish in the new data-intensive environment of twenty-first century science, we need to evolve new skills. These can be expressed in terms of the systemized framework that formed the basis of mediaeval education—the trivium (logic, grammar and rhetoric) and quadrivium (arithmetic, geometry, music and astronomy). However, rather than focusing on number, data are the new keystone. We need to understand what rules they obey, how they are symbolized and communicated, and what their relationship is to physical space and time. In this paper, we will review this understanding in terms of the technologies and processes that data require. We contend that, at least, an appreciation of all these aspects is crucial to enabling us to extract scientific information and knowledge from the data sets that threaten to engulf and overwhelm us.
New Neighbors: Parallaxes of 18 Nearby Stars Selected from the LSPM-North Catalog

We present astrometric parallaxes for 18 suspected nearby stars selected from the LSPM-north proper motion catalog. 16 objects are confirmed to be main-sequence M dwarfs within 16 pc of the Sun, including three stars (LSPM J0011+5908, LSPM J0330+5413, and LSPM J0510+2714) which lie just within the 10 pc horizon. Two other targets (LSPM J1817+1328, LSPM J2325+1403) are confirmed to be nearby white dwarfs at distances of 14 and 22 pc, respectively. One of our targets, the common proper motion pair LSPM J0405+7116E + LSPM J0405+7116W, is revealed to be a triple system, with the western component resolved into a pair of 16th magnitude stars (LSPM J0405+7116W-A and LSPM J0405+7116W-B) with a 0.7 {+-}0.''1 angular separation. We find two stars (LSPM J1314+1320 and LSPM J1757+7042) to be significantly overluminous for their colors, and conclude that these may be unresolved doubles/multiples.
Density of states in the magnetic ground state of the Friedel-Anderson impurity

By applying a magnetic field whose Zeeman energy exceeds the Kondo energy by an order of magnitude the ground state of the Friedel-Anderson impurity is a magnetic state. In recent years the author introduced the FAIR (Friedel Artificially Inserted Resonance) method to investigate the impurity properties. Within this FAIR approach the full excitation spectrum and the composition of the excitations is calculated and numerically evaluated. From the excitation spectrum the electron density of states is calculated. Majority and minority d-resonances are obtained. The width of the resonances is about twice as wide as the mean field theory predicts. This broadening reduces the height of the resonance curve and therefore the density of states by a factor of two. This yields an intuitive understanding for a previous result of the FAIR approach that it requires a much larger Coulomb interaction for the formation of a magnetic moment than the mean field theory.
Cooling Flows and Metallicity Gradients in Clusters of Galaxies

The X-ray emission by hot gas at the centers of clusters of galaxies is commonly modeled assuming the existence of steady state, inhomogeneous cooling flows. We derive the metallicity profiles of the intracluster medium expected from such models. The inflowing gas is chemically enriched by Type Ia supernovas and stellar mass loss in the outer parts of the central galaxy, which may give rise to a substantial metallicity gradient. The amplitude of the expected metallicity enhancement toward a cluster's center is proportional to the ratio of the central galaxy's luminosity to the mass-inflow rate. The metallicity of the hotter phases is expected to be higher than that of the colder, denser phases. The metallicity profile expected for the Centaurus Cluster is in good agreement with the metallicity gradient recently inferred from ASCA measurements. However, current data do not rule out alternative models in which cooling is balanced by some heat source. The metallicity gradient does not need to be present in all clusters, depending on the recent merger history of the gas around the central cluster galaxy and on the ratio of the stellar mass in the central galaxy to the gas mass in the cooling flow.
Molecular Asymmetry and Optical Cycling: Laser Cooling Asymmetric Top Molecules

Laser cooling typically doesn't work on asymmetric molecules, but a new analysis shows that it is possible for certain species, paving the way for a new era for molecular probes.
ON THE ONE-ENDEDNESS OF GRAPHS OF GROUPS

We give a technical result that implies a straightforward necessary and sufficient conditions for a graph of groups with virtually cyclic edge groups to be one ended. For arbitrary graphs of groups, we show that if their fundamental group is not one-ended, then we can blow up vertex groups to graphs of groups with simpler vertex and edge groups. As an application, we generalize a theorem of Swarup to decompositions of virtually free groups.
On the Enhancement of Heat Transfer and Reduction of Entropy Generation by Asymmetric Slip in Pressure-Driven Non-Newtonian Microflows

We study hydrodynamics, heat transfer and entropy generation in pressure-driven microchannel flow of a power-law fluid. Specifically, we address the effect of asymmetry in the slip boundary condition at the channel walls. Constant, uniform but unequal heat fluxes are imposed at the walls in this thermally developed flow. The effect of asymmetric slip on the velocity profile, on the wall shear stress, on the temperature distribution, on the Bejan number profiles, and on the average entropy generation and the Nusselt number are established through the numerical evaluation of exact analytical expressions derived. Specifically, due to asymmetric slip, the fluid momentum flux and thermal energy flux are enhanced along the wall with larger slip, which in turn shifts the location of the velocity's maximum to an off-center location closer to the said wall. Asymmetric slip is also shown to redistribute the peaks and plateaus of the Bejan number profile across the microchannel, showing a sharp transition between entropy generation due to heat transfer and due to fluid flow at an off-center-line location. In the presence of asymmetric slip, the difference in the imposed heat fluxes leads to starkly different Bejan number profiles depending on which wall is hotter, and whether the fluid is shear-thinning or shear-thickening. Overall, slip is shown to promote uniformity in both the velocity field and the temperature field, thereby reducing irreversibility in this flow.
q-deformed Einstein equations from entropic force

In this study, we investigate the influences of fermionic q-deformation on the Einstein equations by taking into account of Verlinde’s entropic gravity approach and Strominger’s proposal on quantum...
ORION’S VEIL: MAGNETIC FIELD STRENGTHS AND OTHER PROPERTIES OF A PDR IN FRONT OF THE TRAPEZIUM CLUSTER

We present an analysis of physical conditions in the Orion Veil, an atomic photon-dominated region (PDR) that lies just in front (≈2 pc) of the Trapezium stars of Orion. This region offers an unusual opportunity to study the properties of PDRs, including the magnetic field. We have obtained 21 cm H i and 18 cm (1665 and 1667 MHz) OH Zeeman effect data that yield images of the line-of-sight magnetic field strength B los in atomic and molecular regions of the Veil. We find B los ≈ −50 to −75 μG in the atomic gas across much of the Veil (25'' resolution) and B los ≈ −350 μG at one position in the molecular gas (40'' resolution). The Veil has two principal H i velocity components. Magnetic and kinematical data suggest a close connection between these components. They may represent gas on either side of a shock wave preceding a weak-D ionization front. Magnetic fields in the Veil H i components are 3–5 times stronger than they are elsewhere in the interstellar medium where N(H) and n(H) are comparable. The H i components are magnetically subcritical (magnetically dominated), like the cold neutral medium, although they are about 1 dex denser. Comparatively strong fields in the Veil H i components may have resulted from low-turbulence conditions in the diffuse gas that gave rise to OMC-1. Strong fields may also be related to magnetostatic equilibrium that has developed in the Veil since star formation. We also consider the location of the Orion-S molecular core, proposing a location behind the main Orion H+ region.
Utility is in the Eye of the User: A Critique of NLP Leaderboards

Benchmarks such as GLUE have helped drive advances in NLP by incentivizing the creation of more accurate models. While this leaderboard paradigm has been remarkably successful, a historical focus on performance-based evaluation has been at the expense of other qualities that the NLP community values in models, such as compactness, fairness, and energy efficiency. In this opinion paper, we study the divergence between what is incentivized by leaderboards and what is useful in practice through the lens of microeconomic theory. We frame both the leaderboard and NLP practitioners as consumers and the benefit they get from a model as its utility to them. With this framing, we formalize how leaderboards -- in their current form -- can be poor proxies for the NLP community at large. For example, a highly inefficient model would provide less utility to practitioners but not to a leaderboard, since it is a cost that only the former must bear. To allow practitioners to better estimate a model's utility to them, we advocate for more transparency on leaderboards, such as the reporting of statistics that are of practical concern (e.g., model size, energy efficiency, and inference latency).
A new SU(2) anomaly

A familiar anomaly affects SU(2) gauge theory in four dimensions: a theory with an odd number of fermion multiplets in the spin 1/2 representation of the gauge group, and more generally in representations of spin 2r + 1/2, is inconsistent. We describe here a more subtle anomaly that can affect SU(2) gauge theory in four dimensions under the condition that fermions transform with half-integer spin under SU(2) and bosons transform with integer spin. Such a theory, formulated in a way that requires no choice of spin structure, and with an odd number of fermion multiplets in representations of spin 4r + 3/2, is inconsistent. The theory is consistent if one picks a spin or spinc structure. Under Higgsing to U(1), the new SU(2) anomaly reduces to a known anomaly of “all-fermion electrodynamics.” Like that theory, an SU(2) theory with an odd number of fermion multiplets in representations of spin 4r + 3/2 can provide a boundary state for a five-dimensional gapped theory whose partition function on a closed five-manifold Y is (−1)∫Yw2w3. All statements have analogs with SU(2) replaced by Sp(2N). There is also an analog in five dimensions.
What is the Computational Value of Finite Range Tunneling

Quantum annealing is a quantum enhanced heuristic optimization algorithm that exploits quantum tunneling. New work shows that it can significantly outperform its classical analog (simulated annealing) as well as the most popular classical algorithm for simulating quantum annealing (quantum Monte Carlo).
Prospects for Measuring the Relative Velocities of Galaxy Clusters in Photometric Surveys Using the Kinetic Sunyaev-Zel'dovich Effect

We consider the prospects for measuring the pairwise kinetic Sunyaev-Zel'dovich (kSZ) signal from galaxy clusters discovered in large photometric surveys such as the Dark Energy Survey (DES). We project that the DES cluster sample will, in conjunction with existing mm-wave data from the South Pole Telescope (SPT), yield a detection of the pairwise kSZ signal at the 8σ-13σ level, with sensitivity peaking for clusters separated by ~100 Mpc distances. A next-generation version of SPT would allow for a 18σ-30σ detection and would be limited by variance from the kSZ signal itself and the residual thermal Sunyaev-Zel'dovich (tSZ) signal. Throughout our analysis, we assume photometric redshift errors that wash out the signal for clusters separated by 50 Mpc; a spectroscopic survey of the DES sample would recover this signal and allow for a 26σ-43σ detection, and would again be limited by kSZ/tSZ variance. Assuming a standard model of structure formation, these high-precision measurements of the pairwise kSZ signal will yield detailed information on the gas content of the galaxy clusters. Alternatively, if the gas can be sufficiently characterized by other means (e.g., using tSZ, X-ray, or weak lensing), then the relative velocities of the galaxy clusters can be isolated, thereby providing a precision measurement of gravity on 100 Mpc scales. We briefly consider the utility of these measurements for constraining theories of modified gravity.
A Matrix-Valued Kuramoto Model

The Kuramoto model is an important model for studying the onset of phase-locking in an ensemble of nonlinearly coupled phase oscillators. Each oscillator has a natural frequency (often taken to be random) and interacts with the other oscillators through the phase difference. It is known that, as the coupling strength is increased, there is a bifurcation in which the incoherent state becomes unstable and a stable phase-locked solution is born. Beginning with the work of Lohe there have been a number of paper that have generalized the Kuramoto model for phase-locking to a non-commuting setting. Here we propose and analyze another such model. We consider a collection of matrix-valued variables that evolve in such a way as to try to align their eigenvector frames. The phase-locked state is one where the eigenframes all align, and thus the matrices all commute. We analyze the stability of the equal frequency phase-locked state and show that it is stable. We also analyze (for the case of symmetric matrices) a dynamic analog of the twist states arising in the standard Kuramoto model, and show that these twist states are dynamically unstable.
Direct detection of light anapole and magnetic dipole DM

We present comparisons of direct detection data for ``light WIMPs'' with an anapole moment interaction (ADM) and a magnetic dipole moment interaction (MDM), both assuming the Standard Halo Model (SHM) for the dark halo of our galaxy and in a halo-independent manner. In the SHM analysis we find that a combination of the 90% CL LUX and CDMSlite limits or the new 90% CL SuperCDMS limit by itself exclude the parameter space regions allowed by DAMA, CoGeNT and CDMS-II-Si data for both ADM and MDM. In our halo-independent analysis the new LUX bound excludes the same potential signal regions as the previous XENON100 bound. Much of the remaining signal regions is now excluded by SuperCDMS, while the CDMSlite limit is much above them. The situation is of strong tension between the positive and negative search results both for ADM and MDM. We also clarify the confusion in the literature about the ADM scattering cross section.
Surgery for partially hyperbolic dynamical systems, I: Blow-ups of invariant submanifolds

We suggest a method to construct new examples of partially hyperbolic diffeomorphisms. We begin with a partially hyperbolic diffeomorphism f : M → M which leaves invariant a submanifold N ⊂ M . We assume that N is an Anosov submanifold for f , that is, the restriction f | N is an Anosov diffeomorphism and the center distribution is transverse to T N ⊂ T M . By replacing each point in N with the projective space (real or complex) of lines normal to N , we obtain the blow-up M . Replacing M with M amounts to a surgery on the neighborhood of N which alters the topology of the manifold. The diffeomorphism f induces a canonical diffeomorphism f : M → M . We prove that under certain assumptions on the local dynamics of f at N the diffeomorphism f is also partially hyperbolic. We also present some modifications, such as the connected sum construction, which allows to “paste together” two partially hyperbolic diffeomorphisms to obtain a new one. Finally, we present several examples to which our results apply.
Compositional Generalization via Neural-Symbolic Stack Machines

Despite achieving tremendous success, existing deep learning models have exposed limitations in compositional generalization, the capability to learn compositional rules and apply them to unseen cases in a systematic manner. To tackle this issue, we propose the Neural-Symbolic Stack Machine (NeSS). It contains a neural network to generate traces, which are then executed by a symbolic stack machine enhanced with sequence manipulation operations. NeSS combines the expressive power of neural sequence models with the recursion supported by the symbolic stack machine. Without training supervision on execution traces, NeSS achieves 100% generalization performance in four domains: the SCAN benchmark of language-driven navigation tasks, the task of few-shot learning of compositional instructions, the compositional machine translation benchmark, and context-free grammar parsing tasks.
Bridging fermionic and bosonic short range entangled states

In this paper we construct bosonic short range entangled (SRE) states in all spatial dimensions by coupling a gauge field to fermionic SRE states with the same symmetries, and driving the gauge field to its confined phase. We demonstrate that this approach allows us to construct many examples of bosonic SRE states, and we demonstrate that the previous descriptions of bosonic SRE states such as the semiclassical nonlinear sigma model field theory and the Chern–Simons field theory can all be derived using the fermionic SRE states.
GRAPH COMPONENTS AND DYNAMICS OVER FINITE FIELDS

For polynomials and rational maps of fixed degree over a finite field, we bound both the average number of components of their functional graphs as well as the average number of periodic points of their associated dynamical systems.
Dark Energy From Dynamical Projective Connections

We further develop the gravitational model, Thomas-Whitehead gravity (TW Gravity), that arises when projective connections become dynamical fields. TW Gravity has its origins in geometric actions from string theory where the TW projective connection appears as a rank two tensor, , on the spacetime manifold. Using a Gauss–Bonnet (GB) action built from the -dimensional TW connection, and applying the tensor decomposition , we arrive at a gravitational model made up of a -dimensional Einstein–Hilbert + GB action sourced by D ab and with cosmological constant . The action is studied and we find that , with J 0 the coupling constant for D ab . For equal to the current measured value, J 0 is on the order of the measured angular momentum of the observable Universe. We view this as controlling the scale of patches of the Universe that acquire angular momentum, with the net angular momentum of multiple patches vanishing, as required by the cosmological principle. We further find a universal axial scalar coupling to all fermions where the trace, acts as the scalar. This suggests that is also a dark matter portal for non-standard model fermions.
Spectral models of convection-dominated accretion flows

For small values of the dimensionless viscosity parameter, namely α 0.1, the dynamics of nonradiating accretion flows is dominated by convection; convection strongly suppresses the accretion of matter onto the central object and transports a luminosity ~ c2 from small to large radii in the flow. A fraction of this convective luminosity is likely to be radiated at large radii via thermal bremsstrahlung emission. We show that this leads to a correlation between the frequency of maximal bremsstrahlung emission and the luminosity of the source, νpeak ∝ L2/3. Accreting black holes with X-ray luminosities 10-4LEdd LX(0.5-10 keV) 10-7LEdd are expected to have hard X-ray spectra, with photon indices Γ ~ 2, and sources with LX 10-9LEdd are expected to have soft spectra, with Γ ~ 3.5. This is testable with Chandra and XMM.
A Generative Adversarial Approach with Residual Learning for Dust and Scratches Artifacts Removal

Retouching can significantly elevate the visual appeal of photos, but many casual photographers lack the expertise to operate in a professional manner. One particularly challenging task for old photo retouching remains the removal of dust and scratches artifacts. Traditionally, this task has been completed manually with special image enhancement software and represents a tedious task that requires special know-how of photo editing applications. However, recent research utilizing Generative Adversarial Networks (GANs) has been proven to obtain good results in various automated image enhancement tasks compared to traditional methods. This motivated us to explore the use of GANs in the context of film photo editing. In this paper, we present a GAN based method that is able to remove dust and scratches errors from film scans. Specifically, residual learning is utilized to speed up the training process, as well as boost the denoising performance. An extensive evaluation of our model on a community provided dataset shows that it generalizes remarkably well, not being dependent on any particular type of image. Finally, we significantly outperform the state-of-the-art methods and software applications, providing superior results.
Universal Collaboration Strategies for Signal Detection: A Sparse Learning Approach

This paper considers the problem of high-dimensional signal detection in a large distributed network whose nodes can collaborate with their one-hop neighboring nodes (spatial collaboration). We assume that only a small subset of nodes communicate with the fusion center (FC). We design optimal collaboration strategies which are universal for a class of deterministic signals. By establishing the equivalence between the collaboration strategy design problem and sparse principal component analysis (PCA), we solve the problem efficiently and evaluate the impact of collaboration on detection performance.
Numerical Solution of Dyson Brownian Motion and a Sampling Scheme for Invariant Matrix Ensembles

The Dyson Brownian Motion (DBM) describes the stochastic evolution of N points on the line driven by an applied potential, a Coulombic repulsion and identical, independent Brownian forcing at each point. We use an explicit tamed Euler scheme to numerically solve the Dyson Brownian motion and sample the equilibrium measure for non-quadratic potentials. The Coulomb repulsion is too singular for the SDE to satisfy the hypotheses of rigorous convergence proofs for tamed Euler schemes (Hutzenthaler et al. in Ann. Appl. Probab. 22(4):1611–1641, 2012). Nevertheless, in practice the scheme is observed to be stable for time steps of O(1/N 2) and to relax exponentially fast to the equilibrium measure with a rate constant of O(1) independent of N. Further, this convergence rate appears to improve with N in accordance with O(1/N) relaxation of local statistics of the Dyson Brownian motion. This allows us to use the Dyson Brownian motion to sample N×N Hermitian matrices from the invariant ensembles. The computational cost of generating M independent samples is O(MN 4) with a naive scheme, and O(MN 3logN) when a fast multipole method is used to evaluate the Coulomb interaction.
Two lines or not two lines? That is the question of gamma ray spectra

Lines in the spectrum of cosmic gamma rays are considered one of the more robust signatures of dark matter annihilation. We consider such processes from an effective field theory vantage, and find that generically, two or more lines are expected, providing an interesting feature that can be exploited for searches and reveal details about the underlying theory of dark matter. Using the 130 GeV feature recently reported in the Fermi-LAT data as an example, we analyze the energy spectrum in the multi-line context and find the data to be consistent with a single ?? line, a single ?Z line or both a ?? and a ?Z line.
Factorization and resummation for groomed multi-prong jet shapes

Observables which distinguish boosted topologies from QCD jets are playing an increasingly important role at the Large Hadron Collider (LHC). These observables are often used in conjunction with jet grooming algorithms, which reduce contamination from both theoretical and experimental sources. In this paper we derive factorization formulae for groomed multi-prong substructure observables, focusing in particular on the groomed D2 observable, which is used to identify boosted hadronic decays of electroweak bosons at the LHC. Our factorization formulae allow systematically improvable calculations of the perturbative D2 distribution and the resummation of logarithmically enhanced terms in all regions of phase space using renormalization group evolution. They include a novel factorization for the production of a soft subjet in the presence of a grooming algorithm, in which clustering effects enter directly into the hard matching. We use these factorization formulae to draw robust conclusions of experimental relevance regarding the universality of the D2 distribution in both e+e− and pp collisions. In particular, we show that the only process dependence is carried by the relative quark vs. gluon jet fraction in the sample, no non-global logarithms from event-wide correlations are present in the distribution, hadronization corrections are controlled by the perturbative mass of the jet, and all global color correlations are completely removed by grooming, making groomed D2 a theoretically clean QCD observable even in the LHC environment. We compute all ingredients to one-loop accuracy, and present numerical results at next-to-leading logarithmic accuracy for e+e− collisions, comparing with parton shower Monte Carlo simulations. Results for pp collisions, as relevant for phenomenology at the LHC, are presented in a companion paper [1].
A physical interpretation of the Titius-Bode rule and its connection to the closed orbits of Bertrand’s theorem

We consider the geometric Titius-Bode rule for the semimajor axes of planetary orbits. We derive an equivalent rule for the midpoints of the segments between consecutive orbits along the radial direction and we interpret it physically in terms of the work done in the gravitational field of the Sun by particles whose orbits are perturbed around each planetary orbit. On such energetic grounds, it is not surprising that some exoplanets in multiple-planet extrasolar systems obey the same relation. However, it is surprising that this simple interpretation of the Titius-Bode rule also reveals new properties of the bound closed orbits predicted by Bertrand’s theorem, which has been known since 1873.
Some new results in random matrices over finite fields

In this note we give various characterizations of random walks with possibly different steps that have relatively large discrepancy from the uniform distribution modulo a prime p, and use these results to study the distribution of the rank of random matrices over F_p and the equi-distribution behavior of normal vectors of random hyperplanes. We also study the probability that a random square matrix is eigenvalue-free, or when its characteristic polynomial is divisible by a given irreducible polynomial in the limit n to infinity in F_p. We show that these statistics are universal, extending results of Stong and Neumann-Praeger beyond the uniform model.