cssi/SciSciGPT-SciSciNet huggingface dataset:
Wide field imaging of distant clusters

Wide field imaging is key to understanding the build-up of distant clusters and their galaxy population. By focusing on the so far unexplored outskirts of clusters, where infalling galaxies first hit the cluster potential and the hot intracluster medium, we can help separate cosmological field galaxy evolution from that driven by environment. I present a selection of recent advancements in this area, with particular emphasis on Hubble Space Telescope wide field imaging, for its superior capability to deliver galaxy morphologies and precise shear maps of distant clusters.
Intersecting D-branes and black holes in type 0 string theory

We study intersecting D-branes in type-0 string theories and show that the Dp±-brane bound states obey similar intersecting rules as the Dp-branes of the type-II theories. The D5±-D1± brane system is studied in detail. We show that the corresponding near-horizon geometry is the AdS3 × S3 × T4 space and that there is no tachyon instability in this background. The Bekenstein-Hawking entropy is calculated. The worldvolume theory on the D5±-D1± system is also studied. This theory contains both bosons and fermions and it is seen to arise as a projection of the supersymmetric gauge theory related to the D5-D1 system of the type-IIB theory. The Bekenstein-Hawking entropy formula is reproduced exactly using the dual conformal field theory.
Faint X-Ray Structure in the Crab Pulsar Wind Nebula

We report on a Chandra observation of the Crab Nebula that gives the first clear view of the faint boundary of the Crab's X-ray-emitting pulsar wind nebula. There is structure in all directions. Fingers, loops, bays, and the south pulsar jet all indicate that either filamentary material or the magnetic field is controlling the relativistic electrons. In general, spectra soften as distance from the pulsar increases but do not change rapidly along linear features. This is particularly true for the pulsar jet. The termination of the jet is abrupt; the east side is close to an [O III] optical filament, which may be blocking propagation on this side. We argue that linear features have ordered magnetic fields and that the structure is determined by the synchrotron lifetime of particles diffusing perpendicular and parallel to the magnetic field. We find no significant evidence for thermal X-rays inside the filamentary envelope.
Quantum forbidden-interval theorems for stochastic resonance

We extend the classical forbidden-interval theorems for a stochastic-resonance noise benefit in a nonlinear system to a quantum-optical communication model and a continuous-variable quantum key distribution model. Each quantum forbidden-interval theorem gives a necessary and sufficient condition that determines whether stochastic resonance occurs in quantum communication of classical messages. The quantum theorems apply to any quantum noise source that has finite variance or that comes from the family of infinite-variance alpha-stable probability densities. Simulations show the predicted noise benefits for the basic quantum communication model and the continuous-variable quantum key distribution model.
Genetic programming approaches to learning fair classifiers

Society has come to rely on algorithms like classifiers for important decision making, giving rise to the need for ethical guarantees such as fairness. Fairness is typically defined by asking that some statistic of a classifier be approximately equal over protected groups within a population. In this paper, current approaches to fairness are discussed and used to motivate algorithmic proposals that incorporate fairness into genetic programming for classification. We propose two ideas. The first is to incorporate a fairness objective into multi-objective optimization. The second is to adapt lexicase selection to define cases dynamically over intersections of protected groups. We describe why lexicase selection is well suited to pressure models to perform well across the potentially infinitely many subgroups over which fairness is desired. We use a recent genetic programming approach to construct models on four datasets for which fairness constraints are necessary, and empirically compare performance to prior methods utilizing game-theoretic solutions. Methods are assessed based on their ability to generate trade-offs of subgroup fairness and accuracy that are Pareto optimal. The result show that genetic programming methods in general, and random search in particular, are well suited to this task.
THE TRANSIT TRANSMISSION SPECTRUM OF A COLD GAS GIANT PLANET

Author(s): Dalba, PA; Muirhead, PS; Fortney, JJ; Hedman, MM; Nicholson, PD; Veyette, MJ | Abstract: We use solar occultations observed by the Visual and Infrared Mapping Spectrometer on board the Cassini Spacecraft to extract the 1-5 μm transmission spectrum of Saturn, as if it were a transiting exoplanet. We detect absorption from methane, ethane, acetylene, aliphatic hydrocarbons, and possibly carbon monoxide, with peak-to-peak features of up to 90 parts-per-million despite the presence of ammonia clouds. We also find that atmospheric refraction, as opposed to clouds or haze, determines the minimum altitude that could be probed during mid-transit. Self-consistent exoplanet atmosphere models show good agreement with Saturn's transmission spectrum but fail to reproduce a large absorption feature near 3.4 μm, likely caused by gaseous ethane and a C-H stretching mode of an unknown aliphatic hydrocarbon. This large feature is located in one of the Spitzer Space Telescope bandpasses and could alter interpretations of transmission spectra if not properly modeled. The large signal in Saturn's transmission spectrum suggests that transmission spectroscopy of cold, long-period gaseous exoplanets should be possible with current and future observatories. Motivated by these results, we briefly consider the feasibility of using a survey to search for and characterize cold exoplanets that are analogous to Jupiter and Saturn utilizing a target-of-opportunity approach.
Inflaton fragmentation and oscillon formation in three dimensions

Analytical arguments suggest that a large class of scalar field potentials permit the existence of oscillons — pseudo-stable, non-topological solitons — in three spatial dimensions. In this paper we numerically explore oscillon solutions in three dimensions. We confirm the existence of these field configurations as solutions to the Klein-Gorden equation in an expanding background, and verify the predictions of Amin and Shirokoff [1] for the characteristics of individual oscillons for their model. Further, we demonstrate that significant numbers of oscillons can be generated via fragmentation of the inflaton condensate, consistent with the analysis of Amin [2]. These emergent oscillons can easily dominate the post-inflationary universe. Finally, both analytic and numerical results suggest that oscillons are stable on timescales longer than the post-inflationary Hubble time. Consequently, the post-inflationary universe can contain an effective matter-dominated phase, during which it is dominated by localized concentrations of scalar field matter.
Density scaling and decoupling in o-terphenyl, salol, and dibutyphthalate

We present new viscosity and equation of state (EoS) results extending to high pressures for o-terphenyl, salol, and dibutylphthalate. Using these and data from the literature, we show that the three liquids all conform to density scaling; that is, their reduced viscosities and reorientational relaxation times are a function of the ratio of temperature and density with the latter raised to a constant. Moreover, the functional form of the dependence on this ratio is independent of the experimental probe of the dynamics. This means that there is no decoupling of the viscosities and relaxation times over the measured range of conditions. Previous literature at odds with these results was based on erroneous extrapolations of the EoS or problematic diamond anvil viscosity data. Thus, there are no exceptions to the experimental fact that every non-associated liquid complies with density scaling with an invariant scaling exponent.
Comparing scientific and technological impact of biomedical research

Abstract Traditionally, the number of citations that a scholarly paper receives from other papers is used as the proxy of its scientific impact. Yet citations can come from domains outside the scientific community, and one such example is through patented technologies—paper can be cited by patents, achieving technological impact. While the scientific impact of papers has been extensively studied, the technological aspect remains less known in the literature. Here we aim to fill this gap by presenting a comparative study on how 919 thousand biomedical papers are cited by U.S. patents and by other papers over time. We observe a positive correlation between citations from patents and from papers, but there is little overlap between the two domains in either the most cited papers, or papers with the most delayed recognition. We also find that the two types of citations exhibit distinct temporal variations, with patent citations lagging behind paper citations for a median of 6 years for the majority of papers. Our work contributes to the understanding of the technological impact of papers.
Fermi Surfaces of Composite Fermions

The fractional quantum Hall (FQH) effect was discovered in two-dimensional electron systems subject to a large perpendicular magnetic field nearly four decades ago. It helped launch the field of topological phases, and in addition, because of the quenching of the kinetic energy, gave new meaning to the phrase “correlated matter.” Most FQH phases are gapped like insulators and superconductors; however, a small subset with even denominator fractional fillings $$\nu $$ of the Landau level, typified by $$\nu =1/2$$ , is found to be gapless, with a Fermi surface akin to metals. We discuss our results, obtained numerically using the infinite density matrix renormalization group scheme, on the effect of non-isotropic distortions with discrete N-fold rotational symmetry of the Fermi surface at zero magnetic field on the Fermi surface of the correlated $$\nu = 1/2$$ state. We find that while the response for $$N = 2$$ (elliptical) distortions is significant (and in agreement with experimental observations with no adjustable parameters), it decreases very rapidly as N is increased. Other anomalies, like resilience to breaking the Fermi surface into disjoint pieces, are also found. This highlights the difference between Fermi surfaces formed from the kinetic energy, and those formed of purely potential energy terms in the Hamiltonian.
The role of turbulence in coronal heating and solar wind expansion.

Plasma in the Sun's hot corona expands into the heliosphere as a supersonic and highly magnetized solar wind. This paper provides an overview of our current understanding of how the corona is heated and how the solar wind is accelerated. Recent models of magnetohydrodynamic turbulence have progressed to the point of successfully predicting many observed properties of this complex, multi-scale system. However, it is not clear whether the heating in open-field regions comes mainly from the dissipation of turbulent fluctuations that are launched from the solar surface, or whether the chaotic ‘magnetic carpet’ in the low corona energizes the system via magnetic reconnection. To help pin down the physics, we also review some key observational results from ultraviolet spectroscopy of the collisionless outer corona.
Unifying Geometrical Representations of Gauge Theory

We unify three approaches within the vast body of gauge-theory research that have independently developed distinct representations of a geometrical surface-like structure underlying the vector-potential. The three approaches that we unify are: those who use the compactified dimensions of Kaluza–Klein theory, those who use Grassmannian models (also called gauge theory embedding or $$CP^{N-1}$$ models) to represent gauge fields, and those who use a hidden spatial metric to replace the gauge fields. In this paper we identify a correspondence between the geometrical representations of the three schools. Each school was mostly independently developed, does not compete with other schools, and attempts to isolate the gauge-invariant geometrical surface-like structures that are responsible for the resulting physics. By providing a mapping between geometrical representations, we hope physicists can now isolate representation-dependent physics from gauge-invariant physical results and share results between each school. We provide visual examples of the geometrical relationships between each school for $$U(1)$$ electric and magnetic fields. We highlight a first new result: in all three representations a static electric field (electric field from a fixed ring of charge or a sphere of charge) has a hidden gauge-invariant time dependent surface that is underlying the vector potential.
On Fomin–Kirillov algebras for complex reflection groups

ABSTRACTIn this note, we apply classification results for finite-dimensional Nichols algebras to generalizations of Fomin–Kirillov algebras to complex reflection groups. First, we focus on the case of cyclic groups where the corresponding Nichols algebras are only finite-dimensional up to order four, and we include results about the existence of Weyl groupoids and finite-dimensional Nichols subalgebras for this class. Second, recent results by Heckenberger–Vendramin [ArXiv e-prints, 1412.0857 (December 2014)] on the classification of Nichols algebras of semisimple group type can be used to find that these algebras are infinite-dimensional for many non-exceptional complex reflection groups in the Shephard–Todd classification.
Local string models of soft supersymmetry breaking

We study soft supersymmetry breaking in local models of type II string theory compactifications with branes and fluxes. In such models, magnetic fluxes can be treated as auxiliary fields in = 2 SUSY multiplets. These multiplets appear as ``spurion superfields'' in the low-energy effective action for the local model. We discuss the pattern of SUSY breaking from = 2 to = 1 to = 0 in these models, and then identify the fields leading to soft SUSY breaking terms in various examples. In the final section, we reconsider arguments for the Dijkgraaf-Vafa conjecture in gauge theories with softly broken supersymmetry.
Khovanov module and the detection of unlinks

We study a module structure on Khovanov homology, which we show is natural under the Ozsvath–Szabo spectral sequence to the Floer homology of the branched double cover. As an application, we show that this module structure detects trivial links. A key ingredient of our proof is that the Λ∗H_1–module structure on Heegaard Floer homology detects S^1 × S^2 connected summands.
Magnetic-island Contraction and Particle Acceleration in Simulated Eruptive Solar Flares

The mechanism that accelerates particles to the energies required to produce the observed high-energy impulsive emission in solar flares is not well understood. Drake et al. proposed a mechanism for accelerating electrons in contracting magnetic islands formed by kinetic reconnection in multi-layered current sheets (CSs). We apply these ideas to sunward-moving flux ropes (2.5D magnetic islands) formed during fast reconnection in a simulated eruptive flare. A simple analytic model is used to calculate the energy gain of particles orbiting the field lines of the contracting magnetic islands in our ultrahigh-resolution 2.5D numerical simulation. We find that the estimated energy gains in a single island range up to a factor of five. This is higher than that found by Drake et al. for islands in the terrestrial magnetosphere and at the heliopause, due to strong plasma compression that occurs at the flare CS. In order to increase their energy by two orders of magnitude and plausibly account for the observed high-energy flare emission, the electrons must visit multiple contracting islands. This mechanism should produce sporadic emission because island formation is intermittent. Moreover, a large number of particles could be accelerated in each magneto hydro dynamic-scale island, which may explain the inferred rates of energetic-electron production in flares. We conclude that island contraction in the flare CS is a promising candidate for electron acceleration in solar eruptions.
Light Microscopy at Maximal Precision

A theoretical model of light spreading and scattering improves accuracy precision of position and size measurements made with an optical microscope by as much as 100 times.
The Stellar Population of Stripped Cluster Spiral NGC 4522: A Local Analog to K+A Galaxies?

We present observations of the stripped Virgo Cluster spiral galaxy NGC 4522, a clear, nearby example of a galaxy currently undergoing interstellar medium-intracluster medium (ISM-ICM) stripping. Utilizing SparsePak integral field spectroscopy on the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5 m telescope and Galaxy Evolution Explorer (GALEX) UV photometry, we present an analysis of the outer disk (r > 3 kpc) stellar population of this galaxy, beyond the H I and Hα truncation radius. We find that the star formation in the gas-stripped outer disk ceased very recently, ~100 Myr ago, in agreement with previous claims that this galaxy is currently being stripped. At the time of this stripping, data and models suggest that the galaxy experienced a modest starburst. The stripping is occurring in a region of the cluster well outside the cluster core, likely because this galaxy is experiencing extreme conditions from a dynamic ICM due to an ongoing subcluster merger. The outer disk has a spectrum of a K+A galaxy, traditionally observed in high-redshift cluster galaxies. In the case of NGC 4522, a K+A spectrum is formed by simple stripping of the interstellar gas by the hot intracluster medium. These data show K+A spectra can be created by cluster processes and that these processes likely extend beyond the cluster core.
Looking in the Right Place for Anomalies: Explainable Ai Through Automatic Location Learning

Deep learning has now become the de facto approach to the recognition of anomalies in medical imaging. Their ‘black box’ way of classifying medical images into anomaly labels poses problems for their acceptance, particularly with clinicians. Current explainable AI methods offer justifications through visualizations such as heat maps but cannot guarantee that the network is focusing on the relevant image region fully containing the anomaly. In this paper we develop an approach to explainable AI in which the anomaly is assured to be overlapping the expected location when present. This is made possible by automatically extracting location-specific labels from textual reports and learning the association of expected locations to labels using a hybrid combination of Bi-Directional Long Short-Term Memory Recurrent Neural Networks (Bi-LSTM) and DenseNet-121. Use of this expected location to bias the subsequent attention-guided inference network based on ResNet101 results in the isolation of the anomaly at the expected location when present. The method is evaluated on a large chest X-ray dataset.
Vibrational Coupling to Epsilon-Near-Zero Waveguide Modes

Epsilon near zero modes offer extreme field enhancement that can be utilized for developing enhanced sensing schemes. However, demonstrations of enhanced spectroscopies have largely exploited surfa...
New identities from quantum-mechanical sum rules of parity-related potentials

We apply quantum-mechanical sum rules to pairs of one-dimensional systems defined by potential energy functions related by parity. Specifically, we consider symmetric potentials, V(x) = V(− x), and their parity-restricted partners, ones with V(x) but defined only on the positive half-line. We extend recent discussions of sum rules for the quantum bouncer by considering the parity-extended version of this problem, defined by the symmetric linear potential, V(z) = F|z| and find new classes of constraints on the zeros of the Airy function, Ai(ζ), and its derivative, Ai'(ζ). We also consider the parity-restricted version of the harmonic oscillator and find completely new classes of mathematical relations, unrelated to those of the ordinary oscillator problem. These two soluble quantum-mechanical systems defined by power-law potentials provide examples of how the form of the potential (both parity and continuity properties) affects the convergence of quantum-mechanical sum rules. We also discuss semi-classical predictions for expectation values and the Stark effect for these systems.
Homological eigenvalues of lifts of pseudo-Anosov mapping classes to finite covers

Let $\Sigma$ be a compact orientable surface of finite type with at least one boundary component. Let $f \in \textup{Mod}(\Sigma)$ be a pseudo Anosov mapping class. We prove a conjecture of McMullen by showing that there exists a finite cover $\widetilde{\Sigma} \to \Sigma$ and a lift $\widetilde{f}$ of $f$ such that $\wt{f}_*: H_1(\wt{\Sigma}; \mathbb{Z}) \to H_1(\wt{\Sigma}; \mathbb{Z})$ has an eigenvalue off the unit circle.
Ken Wilson: Solving the Strong Interactions

Ken Wilson’s ideas on the renormalization group were shaped by his attempts to build a theory of the strong interactions based on the concepts of quantum field theory. I describe the development of his ideas by reviewing four of Wilson’s most important papers.
Effects of temperatures and high pressures on the growth and survivability of methanogens and stable carbon isotope fractionation: implications for deep subsurface life on Mars

In order to examine the potential survivability of life in the Martian deep subsurface, we have investigated the effects of temperature (45°C, 55°C and 65°C) and pressure (1, 400, 800 and 1200 atm) on the growth, carbon isotopic data and morphology of chemolithoautotrophic anaerobic methanogenic archaea, Methanothermobacter wolfeii. The growth and survivability of this methanogen were determined by measuring the methane concentration in headspace gas samples after the cells were returned to their conventional growth conditions. Interestingly, this methanogen survived at all the temperatures and pressures tested. M. wolfeii demonstrated the highest methane concentration following exposure to pressure of 800 atm and a temperature of 65°C. We found that the stable carbon isotopic fractionation of methane, δ13C(CH4), was slightly more enriched in 12C at 1 atm and 55°C than the carbon isotopic data obtained in other temperature and pressure conditions. A comparison of the images of the cells before and after the exposure to different temperatures and pressures did not show any obvious alteration in the morphology of M. wolfeii. The research reported here suggests that at least one methanogen, M. wolfeii, may be able to survive under hypothetical Martian subsurface conditions with respect to temperature and pressure.
A Survey of Multiple Planet Systems

To date, over 30 multiple exoplanet systems are known, and 28% of stars with planets show significant evidence of a second companion. I briefly review these 30 systems individually, broadly grouping them into five categories: 1) systems with 3 or more giant (M sin i> 0.2 MJup) planets, 2) systems with two giant planets in mean motion resonance (MMR), 3) systems with two giant planets not in MMR but whose dynamical evolution is affected by planet-planet interactions, 4) highly hierarchical systems, having two giant planets with very large period ratios (>30:1), and 5) systems of “Super-Earths”, containing only planets with (M sin i< 20 M⊕). It now appears that eccentricities are not markedly higher among planets in known multiple planet systems, and that planets with M sin i< 1 MJup have lower eccentricities than more massive planets. The distribution of semimajor axes for planets in multi-planet systems does not show the 3-day pile-up or the 1 AU “jump” of the apparently-single planet distribution.
VALIDATING TIME-DISTANCE HELIOSEISMOLOGY WITH REALISTIC QUIET-SUN SIMULATIONS

Linear time-distance helioseismic inversions are carried out for vector flow velocities using travel times measured from two ~1002 Mm2 × 20 Mm realistic magnetohydrodynamic quiet-Sun simulations of about 20 hr. The goal is to test current seismic methods on these state-of-the-art simulations. Using recent three-dimensional inversion schemes, we find that inverted horizontal flow maps correlate well with the simulations in the upper ~3 Mm of the domains for several filtering schemes, including phase-speed, ridge, and combined phase-speed and ridge measurements. In several cases, however, the velocity amplitudes from the inversions severely underestimate those of the simulations, possibly indicating nonlinearity of the forward problem. We also find that, while near-surface inversions of the vertical velocities are best using phase-speed filters, in almost all other example cases these flows are irretrievable due to noise, suggesting a need for statistical averaging to obtain better inferences.
A two component link with Alexander polynomial one is concordant to the Hopf link

Topological surgery in dimension four is used to show a two component link with Alexander polynomial one is topologically concordant to the Hopf link. Let L be a two component link in S 3 , an embedding of two disjoint circles which is topologically locally flat, that is, which extends to an embedding of two solid tori. The link has Alexander polynomial one, if, and only if, the first homology of the universal abelian cover of the complement of the link vanishes. If the link has Alexander polynomial one, then the linking number of the two components is one. Two links are concordant if there is a topologically locally flat embedding (S 1 � S 1 ) × I → S 3 × I
On the Unification of Active Galactic Nuclei

The inevitable spread in properties of the toroidal obscuration of active galactic nuclei (AGNs) invalidates the widespread notion that type 1 and 2 AGNs are intrinsically the same objects, drawn randomly from the distribution of torus covering factors. Instead, AGNs are drawn preferentially from the distribution; type 2 are more likely drawn from the distribution higher end, type 1 from its lower end. Type 2 AGNs have a higher IR luminosity, lower narrow-line luminosity, and a higher fraction of Compton thick X-ray obscuration than type 1. Meaningful studies of unification statistics cannot be conducted without first determining the intrinsic distribution function of torus covering factors.
Design of Optimal Sparse Feedback Gains via the Alternating Direction Method of Multipliers

We design sparse and block sparse feedback gains that minimize the variance amplification (i.e., the H2 norm) of distributed systems. Our approach consists of two steps. First, we identify sparsity patterns of feedback gains by incorporating sparsity-promoting penalty functions into the optimal control problem, where the added terms penalize the number of communication links in the distributed controller. Second, we optimize feedback gains subject to structural constraints determined by the identified sparsity patterns. In the first step, the sparsity structure of feedback gains is identified using the alternating direction method of multipliers, which is a powerful algorithm well-suited to large optimization problems. This method alternates between promoting the sparsity of the controller and optimizing the closed-loop performance, which allows us to exploit the structure of the corresponding objective functions. In particular, we take advantage of the separability of the sparsity-promoting penalty functions to decompose the minimization problem into sub-problems that can be solved analytically. Several examples are provided to illustrate the effectiveness of the developed approach.
Energy cascade and scaling in supersonic isothermal turbulence

Supersonic turbulence plays an important role in a number of extreme astrophysical and terrestrial environments, yet its understanding remains rudimentary. We use data from a three-dimensional simulation of supersonic isothermal turbulence to reconstruct an exact fourth-order relation derived analytically from the Navier–Stokes equations (Galtier & Banerjee, Phys. Rev. Lett., vol. 107, 2011, p. 134501). Our analysis supports a Kolmogorov-like inertial energy cascade in supersonic turbulence previously discussed on a phenomenological level. We show that two compressible analogues of the four-fifths law exist describing fifth- and fourth-order correlations, but only the fourth-order relation remains ‘universal’ in a wide range of Mach numbers from incompressible to highly compressible regimes. A new approximate relation valid in the strongly supersonic regime is derived and verified. We also briefly discuss the origin of bottleneck bumps in simulations of compressible turbulence.
Duality of Orthogonal Polynomials on a Finite Set

We prove a certain duality relation for orthogonal polynomials defined on a finite set. The result is used in a direct proof of the equivalence of two different ways (using particles or holes) of computing the correlation functions of a discrete orthogonal polynomial ensemble.
Classical and quantum SUSY breaking effects in IIB local models

We discuss the calculation of soft supersymmery breaking terms in type IIB string theoretic models in the Large Volume Scenario (LVS). The suppression of FCNC gives a lower bound on the size of the compactification volume. This leads to soft terms which are strongly suppressed relative to the gravitino mass so that the dominant contribution to the gaugino massses comes from the Weyl anomaly. The other soft terms are essentially generated by the renormalization group running from the string scale to the TeV scale.
Derived representation theory and the algebraic K‐theory of fields

Quillen’s higher algebraic K-theory for fields F has been the object of intense study since their introduction in 1972 [26]. The main direction of research has been the construction of “descent spectral sequences” whose E2-term involved the cohomology of the absolute Galois groupGF with coefficients in the algebraic K–theory of an algebraically closed. The form of such a spectral sequence was conjectured in [28] and [19], but it was soon realized that it could not be expected to converge to algebraic K exactly. However, it appeared likely that it could converge to algebraic K-groups in sufficiently high dimensions, i.e. in dimensions greater than the cohomological dimension of GF . This observation was formalized into the Quillen-Lichtenbaum conjecture. This conjecture has attracted a great deal of attention. Over the years, a number of special cases [36], [16] have been treated, and partial progress has been made [9]. Voevodsky in [41] proved results which led to the verification of the conjecture at p = 2. More recent work of V. Voevodsky appears to have resolved this long standing conjecture at odd primes as well. Moreover, it also appears to resolve the Beilinson-Lichtenbaum conjecture about the form of a spectral sequence which converges exactly to the algebraic K-theory of F .
A sign assignment in totally twisted Khovanov homology

In [4], Lawrence Roberts introduced a “totally twisted” version of i–graded characteristic-2 Khovanov homology for links. Thomas Jaeger [2] then showed that for knots, the reduced totally twisted Khovanov homology actually coincides with the ordinary reduced Khovanov homology (tensored with a suitable coefficient field). We show how to extend the totally twisted construction over Z, in the context of the odd Khovanov homology of Ozsvath, Rasmussen and Szabo [3]. The result is a chain complex whose homology computes the reduced odd Khovanov homology of knots (again, tensored with a suitable ring). Cancelling some differentials in the complex leads to an equivalent complex whose generators are in bijection with spanning trees of the Tait graph. The coefficient of the differential between two spanning trees is determined up to a sign; the sign ambiguity comes from an analogous ambiguity in odd Khovanov homology, where one must choose a sign assignment on the edges of a cube of resolutions.
A Proof of Friedman’s Ergosphere Instability for Scalar Waves

Let $${(\mathcal{M}^{3+1},g)}$$ be a real analytic, stationary and asymptotically flat spacetime with a non-empty ergoregion $${\mathscr{E}}$$ and no future event horizon $${\mathcal{H}^{+}}$$ . In Friedman (Commun Math Phys 63(3):243–255, 1978), Friedman observed that, on such spacetimes, there exist solutions $${\varphi}$$ to the wave equation $${\square_{g}\varphi=0}$$ such that their local energy does not decay to 0 as time increases. In addition, Friedman provided a heuristic argument that the energy of such solutions actually grows to $${+\infty}$$ . In this paper, we provide a rigorous proof of Friedman’s instability. Our setting is, in fact, more general. We consider smooth spacetimes $${(\mathcal{M}^{d+1},g)}$$ , for any $${d\ge2}$$ , not necessarily globally real analytic. We impose only a unique continuation condition for the wave equation across the boundary $${\partial\mathscr{E}}$$ of $${\mathscr{E}}$$ on a small neighborhood of a point $${p\in\partial\mathscr{E}}$$ . This condition always holds if $${(\mathcal{M},g)}$$ is analytic in that neighborhood of p, but it can also be inferred in the case when $${(\mathcal{M},g)}$$ possesses a second Killing field $${\Phi}$$ such that the span of $${\Phi}$$ and the stationary Killing field T is timelike on $${\partial\mathscr{E}}$$ . We also allow the spacetimes $${(\mathcal{M},g)}$$ under consideration to possess a (possibly empty) future event horizon $${\mathcal{H}^{+}}$$ , such that, however, $${\mathcal{H}^{+}\cap\,\,\mathscr{E}=\emptyset}$$ (excluding, thus, the Kerr exterior family). As an application of our theorem, we infer an instability result for the acoustical wave equation on the hydrodynamic vortex, a phenomenon first investigated numerically by Oliveira et al. in (Phys Rev D 89(12):124008, 2014). Furthermore, as a side benefit of our proof, we provide a derivation, based entirely on the vector field method, of a Carleman-type estimate on the exterior of the ergoregion for a general class of stationary and asymptotically flat spacetimes. Applications of this estimate include a Morawetz-type bound for solutions $${\varphi}$$ of $${\square_{g}\varphi=0}$$ with frequency support bounded away from $${{\omega}=0}$$ and $${{\omega}=\pm\infty}$$ .
Supersymmetry and the Yang-Mills effective action at finite N

We study the effective action of quantum mechanical SU(N) Yang-Mills theories with sixteen supersymmetries and N > 2. We show that supersymmetry requires that the eight fermion terms in the supersymmetric completion of the v4 terms be one-loop exact. We also show that the twelve fermion terms in the supersymmetric completion of the v6 terms are two-loop exact for N = 3. For N > 3, this no longer seems to be true; we are able to find non-renormalization theorems for only certain twelve fermion structures. We call these structures `generalized F-terms.' We argue that as the rank of the gauge group is increased, there can be more generalized F-terms at higher orders in the derivative expansion.
Deep Learning of High-Order Interactions for Protein Interface Prediction

Protein interactions are important in a broad range of biological processes. Traditionally, computational methods have been developed to automatically predict protein interface from hand-crafted features. Recent approaches employ deep neural networks and predict the interaction of each amino acid pair independently. However, these methods do not incorporate the important sequential information from amino acid chains and the high-order pairwise interactions. Intuitively, the prediction of an amino acid pair should depend on both their features and the information of other amino acid pairs. In this work, we propose to formulate the protein interface prediction as a 2D dense prediction problem. In addition, we propose a novel deep model to incorporate the sequential information and high-order pairwise interactions to perform interface predictions. We represent proteins as graphs and employ graph neural networks to learn node features. Then we propose the sequential modeling method to incorporate the sequential information and reorder the feature matrix. Next, we incorporate high-order pairwise interactions to generate a 3D tensor containing different pairwise interactions. Finally, we employ convolutional neural networks to perform 2D dense predictions. Experimental results on multiple benchmarks demonstrate that our proposed method can consistently improve the protein interface prediction performance.
FIRST-ORDER COSMOLOGICAL PERTURBATIONS ENGENDERED BY POINT-LIKE MASSES

In the framework of the concordance cosmological model the first-order scalar and vector perturbations of the homogeneous background are derived in the weak gravitational field limit without any supplementary approximations. The sources of these perturbations (inhomogeneities) are presented in the discrete form of a system of separate point-like gravitating masses. The found expressions for the metric corrections are valid at all (sub-horizon and super-horizon) scales and converge at all points except at locations of the sources. The average values of these metric corrections are zero (thus, first-order backreaction effects are absent). Both the Minkowski background limit and the Newtonian cosmological approximation are reached under certain well-defined conditions. An important feature of the velocity-independent part of the scalar perturbation is revealed: up to an additive constant this part represents a sum of Yukawa potentials produced by inhomogeneities with the same finite time-dependent Yukawa interaction range. The suggested connection between this range and the homogeneity scale is briefly discussed along with other possible physical implications.
Reducing the top quark mass uncertainty with jet grooming

The measurement of the top quark mass has large systematic uncertainties coming from the Monte Carlo simulations that are used to match theory and experiment. We explore how much that uncertainty can be reduced by using jet grooming procedures. Using the ATLAS A14 tunes of pythia, we estimate the uncertainty from the choice of tuning parameters in what is meant by the Monte Carlo mass to be around 530 MeV without any corrections. This uncertainty can be reduced by 60% to 200 MeV by calibrating to the W mass and by 70% to 140 MeV by additionally applying soft-drop jet grooming (or to 170 MeV using trimming). At e + e − colliders, the associated uncertainty is around 110 MeV, reducing to 50 MeV after calibrating to the W mass. By analyzing the tuning parameters, we conclude that the importance of jet grooming after calibrating to the W -mass is to reduce sensitivity to the underlying event.
Alternatives to Research

A FORMIDABLE challenge to excel lence is posed by two trends in collegiate mathematics education: one is the admir able flow of numerous students into fields requiring mathematics, with a consequent demand for good college teachers; the other is the lamentable tendency for undergraduate mathematics faculties to be understaffed and overworked. The two trends together generate a challenge which the CUPM Panel on College Teacher Preparation now confronts: How can undergraduate faculty members achieve and maintain high quality in mathe matics teaching? Let us assume that active enthusiasm for mathematics is one prerequisite for excellent teaching. At universities, we expect research-oriented professors to impart a sense of mathematics as a grow
DETECTING THE SUPERNOVA BREAKOUT BURST IN TERRESTRIAL NEUTRINO DETECTORS

We calculate the distance-dependent performance of a few representative terrestrial neutrino detectors in detecting and measuring the properties of the νe breakout burst light curve in a Galactic core-collapse supernova. The breakout burst is a signature phenomenon of core collapse and offers a probe into the stellar core through collapse and bounce. We examine cases of no neutrino oscillations and oscillations due to normal and inverted neutrino-mass hierarchies. For the normal hierarchy, other neutrino flavors emitted by the supernova overwhelm the νe signal, making a detection of the breakout burst difficult. For the inverted hierarchy (IH), some detectors at some distances should be able to see the νe breakout burst peak and measure its properties. For the IH, the maximum luminosity of the breakout burst can be measured at 10 kpc to accuracies of ~30% for Hyper-Kamiokande (Hyper-K) and ~60% for the Deep Underground Neutrino Experiment (DUNE). Super-Kamiokande (Super-K) and Jiangmen Underground Neutrino Observatory (JUNO) lack the mass needed to make an accurate measurement. For the IH, the time of the maximum luminosity of the breakout burst can be measured in Hyper-K to an accuracy of ~3 ms at 7 kpc, in DUNE to ~2 ms at 4 kpc, and JUNO and Super-K can measure the time of maximum luminosity to an accuracy of ~2 ms at 1 kpc. Detector backgrounds in IceCube render a measurement of the νe breakout burst unlikely. For the IH, a measurement of the maximum luminosity of the breakout burst could be used to differentiate between nuclear equations of state.
Design of a hybrid modular switch

Network Function Virtualization (NFV) shed new light for the design, deployment, and management of cloud networks. Many network functions such as firewalls, load balancers, and intrusion detection systems can be virtualized by servers. However, network operators often have to sacrifice programmability to achieve high throughput, especially at networks' edge where complex network functions are required. Here, we design, implement and evaluate Hybrid Modular Switch (HyMoS). The hybrid hardware/software switch aims to meet the requirements of modern-day NFV applications by providing high-throughput, highly programmable packet forwarding. HyMoS utilizes P4-compatible Network Interface Cards (NICs), PCI Express interface and CPU to act as line cards, switch fabric, and fabric controller respectively. HyMos turns PCI Express interface into a non-blocking switch fabric with a throughput of hundreds of Gigabits per second. Compared to existing NFV infrastructure, HyMoS offers modularity in hardware and software as well as a higher degree of programmability by supporting a superset of P4 language.
Uniqueness of Kerr–Newman–de Sitter Black Holes with Small Angular Momenta

We show that a stationary solution of the Einstein–Maxwell equations which is close to a non-degenerate Reissner–Nordstrom–de Sitter solution is in fact equal to a slowly rotating Kerr–Newman–de Sitter solution. The proof uses the nonlinear stability of the Kerr–Newman–de Sitter family of black holes with small angular momenta, recently established by the author, together with an extension argument for Killing vector fields. Our black hole uniqueness result only requires the solution to have high but finite regularity; in particular, we do not make any analyticity assumptions.
2018 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules

To date, 204 individual molecular species, comprised of 16 different elements, have been detected in the interstellar and circumstellar medium by astronomical observations. These molecules range in size from two atoms to seventy, and have been detected across the electromagnetic spectrum from cm-wavelengths to the ultraviolet. This census presents a summary of the first detection of each molecular species, including the observational facility, wavelength range, transitions, and enabling laboratory spectroscopic work, as well as listing tentative and disputed detections. Tables of molecules detected in interstellar ices, external galaxies, protoplanetary disks, and exoplanetary atmospheres are provided. A number of visual representations of this aggregate data are presented and briefly discussed in context.
Traffic Network Control From Temporal Logic Specifications

We propose a framework for generating a signal control policy for a traffic network of signalized intersections to accomplish control objectives expressible using linear temporal logic. By applying techniques from model checking and formal methods, we obtain a correct-by-construction controller that is guaranteed to satisfy complex specifications. To apply these tools, we identify and exploit structural properties particular to traffic networks that allow for efficient computation of a finite-state abstraction. In particular, traffic networks exhibit a componentwise monotonicity property which enables reaching set computations that scale linearly with the dimension of the continuous state space.
A Volumetric Penrose Inequality for Conformally Flat Manifolds

We consider asymptotically flat Riemannian manifolds with non-negative scalar curvature that are conformal to \({\mathbb{R}^{n}{\setminus} \Omega, n\ge 3}\), and so that their boundary is a minimal hypersurface. (Here, \({\Omega\subset \mathbb{R}^{n}}\) is open bounded with smooth mean-convex boundary.) We prove that the ADM mass of any such manifold is bounded below by \({\frac{1}{2}\left(V/\beta_{n}\right)^{(n-2)/n}}\), where V is the Euclidean volume of Ω and βn is the volume of the Euclidean unit n-ball. This gives a partial proof to a conjecture of Bray and Iga (Commun. Anal. Geom. 10:999–1016, 2002). Surprisingly, we do not require the boundary to be outermost.
Lensed Arcs and Inner Structure of Abell 697

We present new optical observations of the z = 0.282 cluster Abell 697 from Keck Observatory. Images show asymmetric disturbed structure in the cD halo and a previously unknown source that is likely a faint gravitational lens arc. A spectrum of the arc did not yield a redshift, but its spectrum and colors suggest that it lies at z > 1.3. We construct plausible models for the inner cluster potential that are able to reproduce the arc, but in each case the models require the inner potential to be quite elliptical. The cD morphology and the best lens models suggest that this cluster may have undergone a recent merger and is in the process of forming its cD galaxy and halo. Analysis of X-ray data from ROSAT and ASCA suggests that the merging process is sufficiently advanced that the gas in the cluster has relaxed, and A697 lies along the LX-TX relation for normal clusters.
Gamma-Ray Bursts: Temporal Scales and the Bulk Lorentz Factor

For a sample of Swift and Fermi gamma-ray bursts, we show that the minimum variability timescale and the spectral lag of the prompt emission is related to the bulk Lorentz factor in a complex manner. For small Γ's, the variability timescale exhibits a shallow (plateau) region. For large Γ's, the variability timescale declines steeply as a function of Γ (). Evidence is also presented for an intriguing correlation between the peak times, tp, of the afterglow emission and the prompt emission variability timescale.
Bayesian naturalness, simplicity, and testability applied to the $B−L$ MSSM GUT

Recent years have seen increased use of Bayesian model comparison to quantify notions such as naturalness, simplicity, and testability, especially in the area of supersymmetric model building. After demonstrating that Bayesian model comparison can resolve a paradox that has been raised in the literature concerning the naturalness of the proton mass, we apply Bayesian model comparison to GUTs, an area to which it has not been applied before. We find that the GUTs are substantially favored over the non-unifying puzzle model. Of the GUTs we consider, the $B-L$ MSSM GUT is the most favored, but the MSSM GUT is almost equally favored.
Dynamics and center of mass energy of colliding particles around black hole in f(R) gravity

We have investigated the dynamics of particles in the vicinity of a static spherically symmetric black hole in f(R) gravity. Using the Euler Lagrange method, the dynamical equations of a neutral particle are obtained. Assuming that the particle is initially moving in the innermost stable circular orbit (IMSCO), we have calculated its escape velocity, after a collision with some other particle. The conditions for the escape of colliding particles are discussed. The effective potential and the trajectories of the escaping particles are studied graphically.