cssi/SciSciGPT-SciSciNet huggingface dataset:
Do You See What I See? Detecting Hidden Streaming Cameras Through Similarity of Simultaneous Observation

Small, low-cost, wireless cameras are becoming increasingly commonplace making surreptitious observation of people more difficult to detect. Previous work in detecting hidden cameras has only addressed limited environments in small spaces where the user has significant control of the environment. To address this problem in a less constrained scope of environments, we introduce the concept of similarity of simultaneous observation where the user utilizes a camera (Wi-Fi camera, camera on a mobile phone or laptop) to compare timing patterns of data transmitted by potentially hidden cameras and the timing patterns that are expected from the scene that the known camera is recording. To analyze the patterns, we applied several similarity measures and demonstrated an accuracy of over 87% and and F1 score of 0.88 using an efficient threshold-based classification. Furthermore, we used our data set to train a neural network and saw improved results with accuracy as high as 97% and an F1 score over 0.95 for both indoors and outdoors settings. From these results, we conclude that similarity of simultaneous observation is a feasible method for detecting hidden wireless cameras that are streaming video of a user. Our work removes significant limitations that have been put on previous detection methods.
p-adic variation of unit root L-functions

Dwork's conjecture, now proven by Wan, states that unit root L-functions "coming from geometry" are p-adic meromorphic. In this paper we study the p-adic variation of a family of unit root L-functions coming from a suitable family of toric exponential sums. In this setting, we find that the unit root L-functions each have a unique p-adic unit root. We then study the variation of this unit root over the family of unit root L-functions. Surprisingly, we find that this unit root behaves similarly to the classical case of families of exponential sums. That is, the unit root is essentially a ratio of A-hypergeometric functions.
Speculative Thread Framework for Transient Management and Bumpless Transfer in Reconfigurable Digital Filters

There are many methods developed to mitigate transients induced when abruptly changing dynamic algorithms such as those found in digital filters or controllers. These “bumpless transfer” methods have a computational burden to them and take time to implement, causing a delay in the desired switching time. This paper develops a method that automatically reconfigures the computational resources in order to implement a transient management method without any delay in switching times. The method spawns a speculative thread when it predicts if a switch in algorithms is imminent so that the calculations are done prior to the switch being made. The software framework is described and experimental results are shown for a switching between filters in a filter bank.
Photon-Mediated Interactions: A Scalable Tool to Create and Sustain Entangled States of N Atoms

Light-mediated interactions are commonplace in both the laboratory and nature, and now researchers show how to harness them to generate and sustain large-scale quantum entanglement in extended networks of qubits.
Microscopic Control and Detection of Ultracold Strontium in Optical-Tweezer Arrays

A new optical-tweezer design allows researchers to trap and probe single strontium atoms, whose two valence electrons could pave the way to new timekeeping devices and quantum computing architectures.
Estimating decision tree learnability with polylogarithmic sample complexity

We show that top-down decision tree learning heuristics are amenable to highly efficient learnability estimation: for monotone target functions, the error of the decision tree hypothesis constructed by these heuristics can be estimated with polylogarithmically many labeled examples, exponentially smaller than the number necessary to run these heuristics, and indeed, exponentially smaller than information-theoretic minimum required to learn a good decision tree. This adds to a small but growing list of fundamental learning algorithms that have been shown to be amenable to learnability estimation. En route to this result, we design and analyze sample-efficient minibatch versions of top-down decision tree learning heuristics and show that they achieve the same provable guarantees as the full-batch versions. We further give "active local" versions of these heuristics: given a test point $x^\star$, we show how the label $T(x^\star)$ of the decision tree hypothesis $T$ can be computed with polylogarithmically many labeled examples, exponentially smaller than the number necessary to learn $T$.
Recent QCD Results From ATLAS

Recent QCD results from ATLAS taken at 7 TeV center-of-mass energy using the LHC are presented, including: dijet production, isolated photon production, isolated photon production associated with jets, jet shapes in top-quark pair events, the production cross-section of the phi(1020) meson, and underlying event in jet events. Good agreement with theory predictions is seen, in particular with those made by next-to-leading-order generators. These measurements highlight the importance of precision QCD measurements for improving state-of-the-art theoretical tools and searching for new physics.
Microwave emission from aligned dust

Abstract Polarized microwave emission from dust is an important foreground that may contaminate polarized CMB studies unless carefully accounted for. We discuss potential difficulties associated with this foreground, namely, the existence of different grain populations with very different emission/polarization properties and variations of the polarization yield with grain temperature. In particular, we discuss observational evidence in favor of rotational emission from tiny PAH particles with dipole moments, i.e. “spinning dust”, and also consider magneto-dipole emission from strongly magnetized grains. We argue that in terms of polarization, the magneto-dipole emission may dominate even if its contribution to total emissivity is subdominant. Addressing polarized emission at frequencies larger than ∼100 GHz, we discuss the complications arising from the existence of dust components with different temperatures and possibly different alignment properties.
Polynomial knot and link invariants from the virtual biquandle

The Alexander biquandle of a virtual knot or link is a module over a 2-variable Laurent polynomial ring which is an invariant of virtual knots and links. The elementary ideals of this module are then invariants of virtual isotopy which determine both the generalized Alexander polynomial (also known as the Sawollek polynomial) for virtual knots and the classical Alexander polynomial for classical knots. For a fixed monomial ordering <, the Grobner bases for these ideals are computable, comparable invariants which fully determine the elementary ideals and which generalize and unify the classical and generalized Alexander polynomials. We provide examples to illustrate the usefulness of these invariants and propose questions for future work.
Local Statistics of Realizable Vertex Models

We study planar “vertex” models, which are probability measures on edge subsets of a planar graph, satisfying certain constraints at each vertex, examples including the dimer model, and 1-2 model, which we will define. We express the local statistics of a large class of vertex models on a finite hexagonal lattice as a linear combination of the local statistics of dimers on the corresponding Fisher graph, with the help of a generalized holographic algorithm. Using an n × n torus to approximate the periodic infinite graph, we give an explicit integral formula for the free energy and local statistics for configurations of the vertex model on an infinite bi-periodic graph. As an example, we simulate the 1-2 model by the technique of Glauber dynamics.
Effect of Vorticity Coherence on Energy–Enstrophy Bounds for the 3D Navier–Stokes Equations

Bounding curves in the energy, enstrophy-plane are derived for the 3D Navier–Stokes equations under an assumption on coherence of the vorticity direction. The analysis in the critical case where the direction is Holder continuous with exponent r = 1/2 results in a curve with extraordinarily large maximal enstrophy (exponential in Grashof), in marked contrast to the subcritical case, r > 1/2 (algebraic in Grashof).
Behavioral Ethics and the Incidence of Foodborne Illness Outbreaks

Cognitive biases play an important role in creating and perpetuating problems that lead to foodborne illness outbreaks. By using insights from behavioral ethics, we argue that sometimes people engage in unethical behavior that increases the likelihood of foodborne illness outbreaks without necessarily intending to or being consciously aware of it. We demonstrate these insights in an analysis of the 2011 Listeriosis outbreak in the U.S. from the consumption of contaminated cantaloupes. We then provide policy implications that can improve our understanding of other kinds of disease outbreaks and epidemics.
Strong coupling optical spectra in dipole-dipole interacting optomechanical Tavis-Cummings models

We theoretically investigate the emission spectrum of an optomechanical Tavis-Cummings model: two dipole-dipole interacting atoms coupled to an optomechanical cavity (OMC). In particular, we study the influence of dipole-dipole interaction (DDI) on the single-photon spectrum emitted by this hybrid system in the presence of a strong atom-cavity as well as strong optomechanical interaction (hereafter called the strong-strong coupling). We also show that our analysis is amenable to inclusion of the mechanical losses (under the weak mechanical damping limit) and single-photon loss through spontaneous emission from the two-level emitters under a nonlocal Lindblad model.
Asymptotics of Hitchin’s Metric on the Hitchin Section

We consider Hitchin’s hyperkahler metric g on the moduli space $${\mathcal{M}}$$ of degree zero SL(2)-Higgs bundles over a compact Riemann surface. It has been conjectured that, when one goes to infinity along a generic ray in $${\mathcal{M}}$$ , g converges to an explicit “semiflat” metric gsf, with an exponential rate of convergence.We show that this is indeed the case for the restriction of g to the tangent bundle of the Hitchin section $${\mathcal{B} \subset \mathcal{M}}$$ .
Large electron–phonon interactions from FeSe phonons in a monolayer

We show that electron–phonon coupling can induce strong electron pairing in an FeSe monolayer on a SrTiO3 substrate (experimental indications for superconducting are between 65 and 109 K). The role of the SrTiO3 substrate in increasing the coupling is two-fold. First, the interaction of the FeSe and TiO2 terminated face of SrTiO3 prevents the FeSe monolayer from undergoing a shear-type (orthorhombic, nematic) structural phase transition. Second, the substrate allows an anti-ferromagnetic ground state of FeSe which opens electron–phonon coupling channels within the monolayer that are prevented by symmetry in the non-magnetic phase. The spectral function for the electron–phonon coupling () in our calculations agrees well with inelastic tunneling data.
Varicella zoster virus anterior uveitis complicated by thalamic stroke.

We report a case of varicella zoster virus (VZV)-associated anterior uveitis in a patient with weight loss, arthritis and signs of inflammatory bowel disease. Her clinical course included the development of a thalamic stroke secondary to VZV cerebral vasculopathy. Following antiviral therapy, the patient’s neurologic symptoms recovered and her ophthalmic findings improved.
Double Detonations with Thin, Modestly Enriched Helium Layers can Make Normal Type Ia Supernovae

It has been proposed that Type Ia supernovae (SNe Ia) that are normal in their spectra and brightness can be explained by a double detonation that ignites first in a helium shell on the surface of the white dwarf (WD). This proposition is supported by the satisfactory match between simulated explosions of sub-Chandrasekhar-mass WDs with no surface He layer and observations of normal SNe Ia. However, previous calculations of He-ignited double detonations have required either artificial removal of the He shell ashes or extreme enrichment of the surface He layer in order to obtain normal SNe Ia. Here we demonstrate, for the first time in multi-dimensional full-star simulations, that a thin, modestly enriched He layer will lead to a SN Ia that is normal in its brightness and spectra. This strengthens the case for double detonations as a major contributing channel to the population of normal SNe Ia.
Soft factorization in QED from 2D Kac-Moody symmetry

The soft factorization theorem for 4D abelian gauge theory states that the $$ \mathcal{S} $$ -matrix factorizes into soft and hard parts, with the universal soft part containing all soft and collinear poles. Similarly, correlation functions on the sphere in a 2D CFT with a U(1) Kac-Moody current algebra factorize into current algebra and non-current algebra factors, with the current algebra factor fully determined by its pole structure. In this paper, we show that these 4D and 2D factorizations are mathematically the same phenomena. The soft ‘t Hooft-Wilson lines and soft photons are realized as a complexified 2D current algebra on the celestial sphere at null infinity. The current algebra level is determined by the cusp anomalous dimension. The associated complex U(1) boson lives on a torus whose modular parameter is $$ \tau =\frac{2\pi i}{e^2}+\frac{\theta }{2\pi } $$ . The correlators of this 2D current algebra fully reproduce the known soft part of the 4D $$ \mathcal{S} $$ -matrix, as well as a conjectured generalization involving magnetic charges.
Investigation of surface boundary conditions for continuum modeling of RF plasmas

This work was motivated by a lacking general consensus in the exact form of the boundary conditions (BCs) required on the solid surfaces for the continuum modeling of Radiofrequency (RF) plasmas. Various kinds of number and energy density BCs on solid surfaces were surveyed, and how they interacted with the electric potential BC to affect the plasma was examined in two fundamental RF plasma reactor configurations. A second-order local mean energy approximation with equations governing the electron and ion number densities and the electron energy density was used to model the plasmas. Zero densities and various combinations of drift, diffusion, and thermal fluxes were considered to set up BCs. It was shown that the choice of BC can have a significant impact on the sheath and bulk plasma. The thermal and diffusion fluxes to the surface were found to be important. A pure drift BC for dielectric walls failed to produce a sheath.
Identifying the 3FHL Catalog. I. Archival Swift Observations and Source Classification

We present the results of an identification campaign of unassociated sources from the Fermi Large Area Telescope 3FHL catalog. Out of 200 unidentified sources, we selected 110 sources for which archival Swift-XRT observations were available, 52 of which were found to have exactly one X-ray counterpart within the 3FHL 95\% positional uncertainty. In this work, we report the X-ray, optical, IR, and radio properties of these 52 sources using positional associations with objects in various catalogs. The Wide-field Infrared Survey Explorer color-color plot for sources suggests that most of these belong to the blazar class family. The redshift measurements for these objects range from z=0.277 to z=2.1. Additionally, under the assumption that the majority of these sources are blazars, three machine-learning algorithms are employed to classify the sample into flat spectrum radio quasars or BL Lacertae objects. These suggest that the majority of the previously unassociated sources are BL Lac objects, in agreement with the fact the BL Lac objects represent by far the most numerous population detected above 10 GeV in 3FHL.
A First Look at Commercial 5G Performance on Smartphones

We conduct to our knowledge a first measurement study of commercial 5G performance on smartphones by closely examining 5G networks of three carriers (two mmWave carriers, one mid-band carrier) in three U.S. cities. We conduct extensive field tests on 5G performance in diverse urban environments. We systematically analyze the handoff mechanisms in 5G and their impact on network performance. We explore the feasibility of using location and possibly other environmental information to predict the network performance. We also study the app performance (web browsing and HTTP download) over 5G. Our study consumes more than 15 TB of cellular data. Conducted when 5G just made its debut, it provides a “baseline” for studying how 5G performance evolves, and identifies key research directions on improving 5G users’ experience in a cross-layer manner. We have released the data collected from our study (referred to as 5Gophers) at https://fivegophers.umn.edu/www20.
Visualization of Surface-Acoustic-Wave Potential by Transmission-Mode Microwave Impedance Microscopy

Spatially resolved studies of surface acoustic waves (SAWs) are important for advancing acoustoelectronic applications in telecommunication, quantum materials, and phononic crystals, but it is difficult to achieve mesoscopic resolution of such surface-displacement fields. This study uses transmission-mode microwave impedance microscopy to directly image the piezoelectric potential carried by the elastic surface wave. Interference of counterpropagating SAWs and diffraction due to a small domain of opposite polarization are also observed. This technique is sure to facilitate the engineering of SAW devices and complex acoustic metamaterials.
BONDI-HOYLE ACCRETION IN AN ISOTHERMAL MAGNETIZED PLASMA

In regions of star formation, protostars and newborn stars will accrete mass from their natal clouds. These clouds are threaded by magnetic fields with a strength characterized by the plasma β—the ratio of thermal and magnetic pressures. Observations show that molecular clouds have β 1, so magnetic fields have the potential to play a significant role in the accretion process. We have carried out a numerical study of the effect of large-scale magnetic fields on the rate of accretion onto a uniformly moving point particle from a uniform, non-self-gravitating, isothermal gas. We consider gas moving with sonic Mach numbers of up to ; magnetic fields that are either parallel, perpendicular, or oriented 45° to the flow; and β as low as 0.01. Our simulations utilize adaptive mesh refinement in order to obtain high spatial resolution where it is needed; this also allows the boundaries to be far from the accreting object to avoid unphysical effects arising from boundary conditions. Additionally, we show that our results are independent of our exact prescription for accreting mass in the sink particle. We give simple expressions for the steady-state accretion rate as a function of β and for the parallel and perpendicular orientations. Using typical molecular cloud values of and β ~ 0.04 from the literature, our fits suggest that a 0.4 M ☉ star accretes ~4 × 10–9 M ☉ yr–1, almost a factor of two less than accretion rates predicted by hydrodynamic models. This disparity can grow to orders of magnitude for stronger fields and lower Mach numbers. We also discuss the applicability of these accretion rates versus accretion rates expected from gravitational collapse, and under what conditions a steady state is possible. The reduction in the accretion rate in a magnetized medium leads to an increase in the time required to form stars in competitive accretion models, making such models less efficient than predicted by Bondi-Hoyle rates. Our results should find application in numerical codes, enabling accurate sub-grid models of sink particles accreting from magnetized media.
Statistical Study of Solar Dimmings Using CoDiT

We present the results from analyzing the physical and morphological properties of 154 dimmings (transient coronal holes) and the associated flares and coronal mass ejections (CMEs). Each dimming in our 2013 catalog was processed with the semi-automated Coronal Dimming Tracker using Solar Dynamics Observatory AIA 193 A observations and HMI magnetograms. Instead of the typically used difference images, we used our coronal hole detection algorithm to detect transient dark regions "directly" in extreme ultraviolet (EUV) images. This allowed us to study dimmings as the footpoints of CMEs—in contrast with the larger, diffuse dimmings seen in difference images that represent the projected view of the rising, expanding plasma. Studying the footpoint-dimming morphology allowed us to better understand the CME structure in the low corona. While comparing the physical properties of dimmings, flares, and CMEs we were also able to identify relationships between the different parts of this complex eruptive phenomenon. We found that larger dimmings are longer-lived, suggesting that it takes longer to "close down" large open magnetic regions. Also, during their growth phase, smaller dimmings acquire a higher magnetic flux imbalance (i. e., become more unipolar) than larger dimmings. Furthermore, we found that the EUV intensity of dimmings (indicative of local electron density) correlates with how much plasma was removed and how energetic the eruption was. Studying the morphology of dimmings (single, double, fragmented) also helped us identify different configurations of the quasi-open magnetic field.
THE CHANGE OF THE ORBITAL PERIODS ACROSS ERUPTIONS AND THE EJECTED MASS FOR RECURRENT NOVAE CI AQUILAE AND U SCORPII

I report on the cumulative results from a program started 24 years ago designed to measure the orbital period change of recurrent novae (RNe) across an eruption. The goal is to use the orbital period change to measure the mass ejected during each eruption as the key part of trying to measure whether the RNe white dwarfs are gaining or losing mass over an entire eruption cycle, and hence whether they can be progenitors for Type Ia supernovae. This program has now been completed for two eclipsing RNe: CI Aquilae (CI Aql) across its eruption in 2000 and U Scorpii (U Sco) across its eruption in 1999. For CI Aql, I present 78 eclipse times from 1991 to 2009 (including four during the tail of the 2000 eruption) plus two eclipses from 1926 and 1935. For U Sco, I present 67 eclipse times, including 46 times during quiescence from 1989 to 2009, plus 21 eclipse times in the tails of the 1945, 1999, and 2010 eruptions. The eclipse times during the tails of eruptions are systematically and substantially shifted with respect to the ephemerides from the eclipses in quiescence, with this being caused by shifts of the center of light during the eruption. These eclipse times are plotted on an O – C diagram and fitted to models with a steady period change () between eruptions (caused by, for example, conservative mass transfer) plus an abrupt period change (ΔP) at the time of eruption. The primary uncertainty arises from the correlation between ΔP with , such that a more negative makes for a more positive ΔP. For CI Aql, the best fit is ΔP = –3.7+9.2 – 7.3 × 10–7. For U Sco, the best fit is ΔP = (+ 43 ± 69) × 10–7 days. These period changes can directly give a dynamical measure of the mass ejected (M ejecta) during each eruption with negligible sensitivity to the stellar masses and no uncertainty from distances. For CI Aql, the 1σ upper limit is M ejecta < 10 × 10–7 M ☉. For U Sco, I derive M ejecta = (43 ± 67) × 10–7 M ☉.
Four-state nanomagnetic logic using multiferroics

The authors theoretically demonstrate the implementation of a low-power 4-state universal logic gate (NOR) using a linear array of three dipole-coupled magnetostrictive-piezoelectric multiferroic nanomagnets (e.g. Ni/PZT) with biaxial magnetocrystalline anisotropy. The two peripheral nanomagnets in the array encode the 4-state input bits in their magnetization orientations and the central nanomagnet's magnetization orientation represents the output bit. Numerical simulations are performed to confirm that the 4-state output bit is the Boolean NOR function of the two 4-state inputs bits when the array reaches its ground state. A voltage pulse alternating between ?0.2 and +0.2?V, applied to the piezoelectric layer of the central nanomagnet, generates alternating tensile and compressive stress in its magnetostrictive layer. This drives the array to the correct ground state where dipole interaction between the magnets ensures that the output is the NOR function of the input. For the system considered, the gate operation is executed while dissipating only ~33?000?kT (0.138?fJ) of energy.
Challenges in explaining the Galactic Center gamma-ray excess with millisecond pulsars

Millisecond pulsars have been discussed as a possible source of the gamma-ray excess observed from the region surrounding the Galactic Center. With this in mind, we use the observed population of bright low-mass X-ray binaries to estimate the number of millisecond pulsars in the Inner Galaxy. This calculation suggests that only ~ 1–5% of the excess is produced by millisecond pulsars. We also use the luminosity function derived from local measurements of millisecond pulsars, along with the number of point sources resolved by Fermi, to calculate an upper limit for the diffuse emission from such a population. While this limit is compatible with the millisecond pulsar population implied by the number of low-mass X-ray binaries, it strongly excludes the possibility that most of the excess originates from such objects.
ULAS J141623.94+134836.3: A Blue T Dwarf Companion to a Blue L Dwarf

We confirm the substellar nature of ULAS J141623.94+134836.3 (aka SDSS J1416+1348B), a common proper motion companion to the blue L dwarf SDSS J141624.08+134826.7 identified by Burningham et al. and Scholz. Low-resolution 0.8-2.4 μm spectroscopy obtained with the Infrared Telescope Facility/SpeX shows strong H2O and CH4 absorption bands, consistent with a T7.5 spectral type, and we see possible indications of NH3 absorption in the 1.0-1.3 μm region. More importantly, the spectrum of SDSS J1416+1348B shows a broadened Y-band peak and highly suppressed K-band flux, both indicative of high surface gravity and/or subsolar metallicity. These traits are verified through spectral model fits, from which we derive atmospheric parameters T eff = 650 ± 60 K, log g = 5.2 ± 0.4 cgs, [M/H] ≤ –0.3, and Kzz = 104 cm2 s–1, the temperature being significantly warmer than that estimated by Burningham et al. These fits also indicate a model-dependent spectroscopic distance of 10.6+3.0 –2.8 pc for SDSS J1416+1348B, formally consistent with the 7.9 ± 1.7 pc astrometric distance for SDSS J1416+1348A from Scholz. The common peculiarities of these two co-spatial, co-moving sources suggest that their unusual blue colors—and those of other blue L and T dwarfs in general—arise from age/gravity or metallicity effects, rather than cloud properties alone.
A Constraint on the Formation of Dwarf Elliptical Galaxies in the Dense Coma Cluster Core

Deep CCD photometry and positions for a new sample of 250 dwarf elliptical (dE) galaxies in the Coma cluster core are analyzed. A significant color gradient is detected in their projected radial distribution, given by Δ(B-R)/Δ(log Rcc) = -0.08 ± 0.02 mag. Calibrating these dE galaxies against Galactic globular clusters yields a corresponding metallicity gradient which goes as Z ∝ Rcc−0.29. Simulations reveal that this gradient in the projected radial distribution corresponds to a true (three-dimensional) radial color gradient which goes as Δ(B-R)/Δ(log r) -0.20 mag, or Z ∝ r-0.69, over the same radial range. If this radial gradient is a primordial one, it is consistent with a model in which the intracluster gas exerted a significant confinement pressure, impeding the outflow of supernovae-driven metal-rich gas from the young dE galaxies.
MeV-GeV Emission from Neutron-loaded Short Gamma-Ray Burst Jets

Recent discovery of the afterglow emission from short gamma-ray bursts suggests that binary neutron star or black hole-neutron star binary mergers are the likely progenitors of these short bursts. The accretion of neutron star material and its subsequent ejection by the central engine implies a neutron-rich outflow. We consider here a neutron-rich relativistic jet model of short bursts and investigate the high-energy neutrino and photon emission as neutrons and protons decouple from each other. We find that upcoming neutrino telescopes are unlikely to detect the 50 GeV neutrinos expected in this model. For bursts at z ~ 0.1, we find that the Gamma-Ray Large Area Space Telescope (GLAST) and ground-based Cerenkov telescopes should be able to detect prompt 100 MeV and 100 GeV photon signatures, respectively, which may help test the neutron star merger progenitor identification.
Overview on jet results from STAR

Full jet reconstruction allows access to the parton kinematics over a large energy domain and can be used to constrain the mechanisms of energy loss in heavy-ion collisions. Such measurements are challenging at RHIC, due to the high-multiplicity environments created in heavy-ion collisions. In these proceedings, we report an overview of the results on full jet reconstruction obtained by the STAR experiment. Jet measurements in 200 GeV p+p show that jets are calibrated pQCD probes and provide a baseline for jet measurements in Au+Au collisions. Inclusive differential jet production cross sections and ratios are reported for central 200 GeV Au+Au collisions and compared to p+p. We also present measurements of fully reconstructed di-jets at mid-rapidity, and compare spectra and fragmentation functions in p+p and central Au+Au collisions.
Enumeration of m-endomorphisms

An m-endomorphism on a free semigroup is an endomorphism that sends every generator to a word of length m. Two m-endomorphisms are combinatorially equivalent if they are conjugate under an automorphism of the semigroup. In this paper, we specialize an argument of N. G. de Bruijn to produce a formula for the number of combinatorial equivalence classes of m-endomorphisms on a rank-n semigroup. From this formula, we derive several little-known integer sequences.
Quality versus quantity in scientific impact

Abstract Citation metrics are becoming pervasive in the quantitative evaluation of scholars, journals, and institutions. Hiring, promotion, and funding decisions increasingly rely on a variety of impact metrics that cannot disentangle quality from quantity of scientific output, and are biased by factors such as discipline and academic age. Biases affecting the evaluation of single papers are compounded when one aggregates citation-based metrics across an entire publication record. It is not trivial to compare the quality of two scholars that during their careers have published at different rates, in different disciplines, and in different periods of time. Here we evaluate a method based on the generation of a statistical baseline specifically tailored on the academic profile of each researcher. We demonstrate the effectiveness of the approach in decoupling the roles of quantity and quality of publications to explain how a certain level of impact is achieved. The method can be extended to simultaneously suppress any source of bias. As an illustration, we use it to capture the quality of the work of Nobel laureates irrespective of number of publications, academic age, and discipline, even when traditional metrics indicate low impact in absolute terms. The procedure is flexible enough to allow for the evaluation of, and fair comparison among, arbitrary collections of papers – scholar publication records, journals, and institutions; in fact, it extends a similar technique that was previously applied to the ranking of research units and countries in specific disciplines ( Crespo, Ortuno-Orti, & Ruiz-Castillo, 2012 ). We further apply the methodology to almost a million scholars and over six thousand journals to measure the impact that cannot be explained by the volume of publications alone.
The classification of compact simply connected biquotients in dimension 6 and 7

We classify all compact simply connected biquotients of dimension 6 and 7. For each 6-dimensional biquotient, all pairs of groups (G, H) and homomorphisms $$H\rightarrow G\times G$$ giving rise to it are classified.
COLLISION-INDUCED MAGNETIC RECONNECTION AND A UNIFIED INTERPRETATION OF POLARIZATION PROPERTIES OF GRBs AND BLAZARS

The jet composition and energy dissipation mechanism of gamma-ray bursts (GRBs) and blazars are fundamental questions that remain not fully understood. One plausible model is to interpret the ! -ray emission of GRBs and optical emission of blazars as synchrotron radiation of electrons accelerated from the collision-induced magnetic dissipation regions in Poynting-! ux-dominated jets. The polarization observation is an important and independent information to test this model. Based on our recent 3D relativistic MHD simulations of collision-induced magnetic dissipation of magnetically dominated blobs, here we perform calculations of the polarization properties of the emission in the dissipation region and apply the results to model the polarization observational data of GRB prompt emission and blazar optical emission. We show that the same numerical model with different input parameters can reproduce well the observational data of both GRBs and blazars, especially the 90° polarization angle (PA) change in GRB 100826A and the 180° PA swing in blazar 3C279. This supports a uni" ed model for GRB and blazar jets, suggesting that collision-induced magnetic reconnection is a common physical mechanism to power the relativistic jet emission from events with very different black hole masses.
Scaling Phononic Quantum Networks of Solid-State Spins with Closed Mechanical Subsystems

A proposed quantum network architecture offers a solution to the problems inherent in linking qubits with mechanical waves, which have several advantages over photons as information carriers.
Electron phase-space hole transverse instability at high magnetic field

Analytic treatment is presented of the electrostatic instability of an initially planar electron hole in a plasma of effectively infinite particle magnetization. It is shown that there is an unstable mode consisting of a rigid shift of the hole in the trapping direction. Its low frequency is determined by the real part of the force balance between the Maxwell stress arising from the transverse wavenumber with hole depth are derived. Particle in cell simulations show that the slow-growing instabilities previously investigated as coupled hole–wave phenomena occur at the predicted frequency, but with growth rates 2 to 4 times greater than the analytic prediction. This higher rate may be caused by a reduced resonant stabilization because of numerical phase-space diffusion in the simulations.
Predictive coding in balanced neural networks with noise, chaos and delays

Biological neural networks face a formidable task: performing reliable computations in the face of intrinsic stochasticity in individual neurons, imprecisely specified synaptic connectivity, and nonnegligible delays in synaptic transmission. A common approach to combatting such biological heterogeneity involves averaging over large redundant networks of $N$ neurons resulting in coding errors that decrease classically as $1/\sqrt{N}$. Recent work demonstrated a novel mechanism whereby recurrent spiking networks could efficiently encode dynamic stimuli, achieving a superclassical scaling in which coding errors decrease as $1/N$. This specific mechanism involved two key ideas: predictive coding, and a tight balance, or cancellation between strong feedforward inputs and strong recurrent feedback. However, the theoretical principles governing the efficacy of balanced predictive coding and its robustness to noise, synaptic weight heterogeneity and communication delays remain poorly understood. To discover such principles, we introduce an analytically tractable model of balanced predictive coding, in which the degree of balance and the degree of weight disorder can be dissociated unlike in previous balanced network models, and we develop a mean field theory of coding accuracy. Overall, our work provides and solves a general theoretical framework for dissecting the differential contributions neural noise, synaptic disorder, chaos, synaptic delays, and balance to the fidelity of predictive neural codes, reveals the fundamental role that balance plays in achieving superclassical scaling, and unifies previously disparate models in theoretical neuroscience.
Characterizing the AB Doradus Moving Group Via High Resolution Spectroscopy and Kinematic Traceback

We present a detailed analysis of 10 proposed F and G members of the nearby, young moving group AB Doradus (ABD). Our sample was obtained using the 2.7m telescope at the McDonald Observatory with the coude echelle spectrograph, achieving R 60,000 and S/N 200. We derive spectroscopic Teff , log(g), [Fe/H], and microturbulance (vt) using a bootstrap method of the TGVIT software resulting in typical errors of 33K in Teff , 0.08 dex in log(g), 0.03 dex in [Fe/H], and 0.13 km s 1 in vt. Characterization of the ABD sample is performed in three ways: (1) Chemical homogeneity, (2) Kinematic Traceback, and (3) Isochrone tting. We nd the average metal abundance is [M/H] = -0.03 0.06 with a traceback age of 125 Myrs. Our stars were t to 3 dierent evolution
Non-abelian axial-vector duality: a geometric description

Abstract We give a geometric characterization of the quasi axial-vector (Kiritsis-Obers) target space duality in the spirit of the bi-algebra (Klimcik-Severa) approach. We show that the σ-models constructed by taking quotients have non-abelian chiral currents that obey “non-commutative conservation laws” and provide the criterion for a σ-model to have a dual using the axial-vector procedure.
Learning Time Reduction Using Warm-Start Methods for a Reinforcement Learning-Based Supervisory Control in Hybrid Electric Vehicle Applications

Reinforcement learning (RL) is gradually being implemented in the hybrid electric vehicle (HEV) supervisory control. Even though RL exhibits significant fuel consumption saving, the long learning time makes it hardly applicable in real-world vehicles. This study aims to reduce the learning iterations of Q-learning in HEV application utilizing warm-start methods. Different from previous studies, which initiated Q-learning with zero or random Q values, this study initiates the Q-learning with different supervisory controls, and the detailed analysis is given. The results show that the proposed warm-start Q-learning requires 68.8% fewer iterations than cold-start Q-learning and improves 10%–16% MPG compared with equivalent consumption minimization strategy control. The results of this study can be used to facilitate the deployment of RL in vehicle applications.
Comments on a covariant entropy conjecture

Recently Bousso conjectured the entropy crossing a certain light-like hypersurface is bounded by the surface area. We point out a number of difficulties with this conjecture.
Hyperuniformity with no fine tuning in sheared sedimenting suspensions

Particle suspensions, present in many natural and industrial settings, typically contain aggregates or other microstructures that can complicate macroscopic flow behaviors and damage processing equipment. Recent work found that applying uniform periodic shear near a critical transition can reduce fluctuations in the particle concentration across all length scales, leading to a hyperuniform state. However, this strategy for homogenization requires fine tuning of the strain amplitude. Here we show that in a model of sedimenting particles under periodic shear, there is a well-defined regime at low sedimentation speed where hyperuniform scaling automatically occurs. Our simulations and theoretical arguments show that the homogenization extends up to a finite length scale that diverges as the sedimentation speed approaches zero.
Obliquity Evolution of Circumstellar Planets in Sun-like Stellar Binaries

Changes in planetary obliquity, or axial tilt, influence the climates on Earth-like planets. In the solar system, the Earth's obliquity is stabilized due to interactions with our moon and the resulting {small amplitude variations ($\sim$2.4\degree)} are beneficial for advanced life. Most Sun-like stars have at least one stellar companion and the habitability of circumstellar exoplanets is shaped by their stellar companion. We show that a stellar companion can dramatically change whether {Earth-like obliquity stability is} possible through planetary orbital precession relative to the binary orbit or resonant pumping of the obliquity through spin-orbit interactions. We present a new formalism for the planetary spin precession that accounts for orbital misalignments between the planet and binary. Using numerical modeling in $\alpha$ Centauri AB we show: a stark contrast between the planetary obliquity variations depending on the host star, planetary neighbors limit the possible spin states for {Earth-like obliquity stability}, and the presence of a moon can destabilize the obliquity, defying our Earth-based expectations. An Earth-like rotator orbiting the primary star would experience {small} obliquity variations for 87\%, 74\%, or 54\% of Solar type binaries, depending on the mass of the primary (0.8, 1.0, or 1.2 M$_\odot$, respectively). Thus, Earth-like planets likely experience much larger obliquity variations, with more extreme climates, unless they are in specific states, such as orbiting nearly planar with the binary and rotating retrograde (backwards) like Venus.
Tuning and stabilizing topological insulator Bi2Se3 in the intrinsic regime by charge extraction with organic overlayers

In this work, we use charge extraction via organic overlayer deposition to lower the chemical potential of topological insulator (TI) Bi2Se3 thin films into the intrinsic (bulk-insulating) regime. We demonstrate the tuning and stabilization of intrinsic topological insulators at high mobility with low-cost organic films. With the protection of the organic charge extraction layers tetrafluorotetracyanoquinodimethane or tris(acetylacetonato)cobalt(III) (Co(acac)3), the sample is stable in the atmosphere with chemical potential ∼135 meV above the Dirac point (85 meV below the conduction band minimum, well within the topological insulator regime) after four months, which is an extraordinary level of environmental stability. The Co complex demonstrates the use of an organometallic for modulating TI charge density. The mobility of surface state electrons is enhanced as high as ∼2000 cm2/V s. Even at room temperature, a true topologically insulating state is realized and stabilized for months' exposure to the at...
Emergent eigenstate solution to quantum dynamics far from equilibrium

Quantum systems that are far from equilibrium can exhibit strange behavior, such as the emergence of coherence in an expanding Bose gas in an optical lattice. A theoretical analysis provides new insight into this phenomenon and a toolkit for understanding a wide range of similar phenomena.
Reduced Chemistry for a Gasoline Surrogate Valid at Engine-Relevant Conditions

A detailed mechanism for the four-component RD387 gasoline surrogate developed by Lawrence Livermore National Laboratory has shown good agreement with experiments in engine-relevant conditions. However, with 1388 species and 5933 reversible reactions, this detailed mechanism is far too large to use in practical engine simulations. Therefore, reduction of the detailed mechanism was performed using a multi-stage approach consisting of the directed relation graph with error propagation and sensitivity analysis (DRGEPSA) method, unimportant reaction elimination, isomer lumping, and analytical quasi-steady-state (QSS) reduction based on computational singular perturbation (CSP) analysis. A new greedy sensitivity analysis algorithm was developed and demonstrated to be capable of removing more species for the same error limit compared to the conventional sensitivity analysis used in directed relation graph (DRG)-based skeletal reduction methods. Using this new greedy algorithm, several skeletal and reduced mecha...
Two-loop superstrings III: Slice independence and absence of ambiguities

Abstract The chiral superstring measure constructed in the earlier papers of this series for general gravitino slices χ z + is examined in detail for slices supported at two points x1 and x2, χ z + =ζ 1 δ(z,x 1 )+ζ 2 δ(z,x 2 ) , where ζ1 and ζ2 are the odd Grassmann valued supermoduli. In this case, the invariance of the measure under infinitesimal changes of gravitino slices established previously is strengthened to its most powerful form: the measure is shown, point-by-point on moduli space, to be locally and globally independent from xα, as well as from the superghost insertion points pa, qα introduced earlier as computational devices. In particular, the measure is completely unambiguous. The limit xα=qα is then well defined. It is of special interest, since it elucidates some subtle issues in the construction of the picture-changing operator Y(z) central to the BRST formalism. The formula for the chiral superstring measure in this limit is derived explicitly.
Phosphorylation by the stress-activated MAPK Slt2 down-regulates the yeast TOR complex 2

Saccharomyces cerevisiae target of rapamycin (TOR) complex 2 (TORC2) is an essential regulator of plasma membrane lipid and protein homeostasis. How TORC2 activity is modulated in response to changes in the status of the cell envelope is unclear. Here we document that TORC2 subunit Avo2 is a direct target of Slt2, the mitogen-activated protein kinase (MAPK) of the cell wall integrity pathway. Activation of Slt2 by overexpression of a constitutively active allele of an upstream Slt2 activator (Pkc1) or by auxin-induced degradation of a negative Slt2 regulator (Sln1) caused hyperphosphorylation of Avo2 at its MAPK phosphoacceptor sites in a Slt2-dependent manner and diminished TORC2-mediated phosphorylation of its major downstream effector, protein kinase Ypk1. Deletion of Avo2 or expression of a phosphomimetic Avo2 allele rendered cells sensitive to two stresses (myriocin treatment and elevated exogenous acetic acid) that the cell requires Ypk1 activation by TORC2 to survive. Thus, Avo2 is necessary for optimal TORC2 activity, and Slt2-mediated phosphorylation of Avo2 down-regulates TORC2 signaling. Compared with wild-type Avo2, phosphomimetic Avo2 shows significant displacement from the plasma membrane, suggesting that Slt2 inhibits TORC2 by promoting Avo2 dissociation. Our findings are the first demonstration that TORC2 function is regulated by MAPK-mediated phosphorylation.
Charged Grain Boundaries and Carrier Recombination in Polycrystalline Thin-Film Solar Cells

Thin-film polycrystalline photovoltaics like CdTe possess high power-conversion efficiency, but still suffer from low open-circuit voltage ${V}_{O\phantom{\rule{0}{0ex}}C}$. Grain boundaries are believed to reduce ${V}_{O\phantom{\rule{0}{0ex}}C}$, yet a precise understanding of their impact on device performance is lacking. The authors derive analytic expressions for ${V}_{O\phantom{\rule{0}{0ex}}C}$ in terms of grain-boundary and material parameters for various grain-boundary defect configurations, and verify their results against numerical simulations. Their insight should assist in optimizing the defect chemistry of grain boundaries and mitigating their impact on ${V}_{O\phantom{\rule{0}{0ex}}C}$, on the way to a solar-powered future.