cssi/SciSciGPT-SciSciNet huggingface dataset:
SCALING OF THE ANOMALOUS BOOST IN RELATIVISTIC JET BOUNDARY LAYER

We investigate the one-dimensional interaction of a relativistic jet and an external medium. Relativistic magnetohydrodynamic simulations show an anomalous boost of the jet fluid in the boundary layer, as previously reported. We describe the boost mechanism using an ideal relativistic fluid and magnetohydrodynamic theory. The kinetic model is also examined for further understanding. Simple scaling laws for the maximum Lorentz factor are derived, and verified by the simulations.
RESOLVING THE MERGING PLANCK CLUSTER PLCK G147.3-16.6 WITH GISMO

The Planck satellite has recently completed an all-sky galaxy cluster survey exploiting the thermal Sunyaev–Zel'dovich (SZ) effect to locate some of the most massive systems observable. With a median redshift of =0.22, the clusters found by Planck at z > 0.3 are proving to be exceptionally massive and/or disturbed systems. One notable Planck discovery at z = 0.645, PLCK G147.3-16.6, has an elongated core and hosts a radio halo, indicating it is likely in the process of merging. We present a 16".5 resolution SZ observation of this high-z merger using the Goddard-IRAM Superconducting 2-Millimeter Observer, and compare it to X-ray follow-up observations with XMM-Newton. We find the SZ pressure substructure is offset from the core components seen in X-ray. We interpret this as possible line of sight temperature or density substructure due to the on-going merger.
On Identifiability of Nonnegative Matrix Factorization

In this letter, we propose a new identification criterion that guarantees the recovery of the low-rank latent factors in the nonnegative matrix factorization (NMF) generative model, under mild conditions. Specifically, using the proposed criterion, it suffices to identify the latent factors if the rows of one factor are sufficiently scattered over the nonnegative orthant, while no structural assumption is imposed on the other factor except being full-rank. This is by far the mildest condition under which the latent factors are provably identifiable from the NMF model.
Capacity bounds via operator space methods

We prove that for generalized dephasing channels, the coherent information and reverse coherent information coincides. It also implies an alternative approach for the strong super-additivity and strong converse of generalized dephasing channels using the operator space technique. Our argument is based on an improved Renyi relative entropy estimate via analyzing the channel’s Stinespring space. We also apply this estimate to new examples of quantum channels arising from quantum group co-representation and Kitave’s quantum computation model. In particular, we find concrete examples of non-degradable channels that our estimates are tight and give a formula of nontrivial quantum capacity.
R&D on GEM detectors for forward tracking at a future Electron-Ion Collider

We report the status of R&D on large triple-GEM detectors for a forward tracker (FT) in an experiment at a future Electron Ion Collider (EIC) that will improve our understanding of QCD. We have designed a detector prototype specifically targeted for the EIC-FT, which has a trapezoidal shape with 30.1° opening angle. We are investigating different detector assembly techniques and signal readout technologies, but have designed a common GEM foil to minimize NRE cost for foil production. The assembly techniques comprise either a purely mechanical method including foil stretching as pioneered by CMS but with certain modifications, or gluing foils to frames that are then assembled mechanically, or gluing foils to frames that are then glued together. The first two assembly techniques allow for re-opening chambers so that a GEM foil can be replaced if it is damaged. For readout technologies, we are pursuing a cost-effective one-dimensional readout with wide zigzag strips that maintains reasonable spatial resolution, as well two-dimensional readouts — one with stereo-angle (u-v) strips and another with r-φ strips. In addition, we aim at an overall low-mass detector design to facilitate good energy resolution for electrons scattered at low momenta. We present design for GEM foils and other detector parts, which we plan to entirely acquire from U.S. companies.
THE CORONAL ABUNDANCE ANOMALIES OF M DWARFS

We analyze Chandra X-ray spectra of the M0 V+M0 V binary GJ 338. As quantified by X-ray surface flux, these are the most inactive M dwarfs ever observed with X-ray grating spectroscopy. We focus on measuring coronal abundances, in particular searching for evidence of abundance anomalies related to first ionization potential (FIP). In the solar corona and wind, low-FIP elements are overabundant, which is the so-called FIP effect. For other stars, particularly very active ones, an 'inverse FIP effect' is often observed, with low-FIP elements being underabundant. For both members of the GJ 338 binary, we find evidence for a modest inverse FIP effect, consistent with expectations from a previously reported correlation between spectral type and FIP bias. This amounts to strong evidence that all M dwarfs should exhibit the inverse FIP effect phenomenon, not just the active ones. We take the first step toward modeling the inverse FIP phenomenon in M dwarfs, building on past work that has demonstrated that MHD waves coursing through coronal loops can lead to a ponderomotive force that fractionates elements in a manner consistent with the FIP effect. We demonstrate that in certain circumstances this model can also lead to an inverse FIP effect,more » pointing the way to more detailed modeling of M dwarf coronal abundances in the future.« less
Learning to Recommend Signal Plans under Incidents with Real-Time Traffic Prediction:

The main question to address in this paper is to recommend optimal signal timing plans in real time under incidents by incorporating domain knowledge developed with the traffic signal timing plans ...
Cycles in the de Rham cohomology of abelian varieties over number fields

In his 1982 paper, Ogus defined a class of cycles in the de Rham cohomology of smooth proper varieties over number fields. This notion is a crystalline analogue of -adic Tate cycles. In the case of abelian varieties, this class includes all the Hodge cycles by the work of Deligne, Ogus, and Blasius. Ogus predicted that such cycles coincide with Hodge cycles for abelian varieties. In this paper, we confirm Ogus’ prediction for some families of abelian varieties. These families include geometrically simple abelian varieties of prime dimension that have non-trivial endomorphism ring. The proof uses a crystalline analogue of Faltings’ isogeny theorem due to Bost and the known cases of the Mumford–Tate conjecture.
Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies. I. Spatially Resolved Mass Outflow Rates for the Seyfert 2 Galaxy Markarian 573

We present the first spatially resolved mass outflow rate measurements ($\dot M_{out}$) of the optical emission line gas in the narrow line region (NLR) of a Seyfert 2 galaxy, Markarian 573. Using long slit spectra and [O III] imaging from the Hubble Space Telescope and Apache Point Observatory in conjunction with emission line diagnostics and Cloudy photoionization models, we find a peak outflow rate of $\dot M_{out} \approx$ 3.4 $\pm$ 0.5 $M_{\odot}$ yr$^{-1}$ at a distance of 210 pc from the central supermassive black hole (SMBH). The outflow extends to distances of 600 pc from the nucleus with a total mass and kinetic energy of $M \approx 2.2 \times 10^6 M_{\odot}$ and $E \approx 5.1 \times 10^{54}$ erg, revealing the outflows to be more energetic than those in the lower luminosity Seyfert 1 galaxy NGC 4151 (Crenshaw et al. 2015). The peak outflow rate is an order of magnitude larger than the mass accretion and nuclear outflow rates, indicating local in-situ acceleration of the circumnuclear NLR gas. We compare these results to global techniques that quantify an average outflow rate across the NLR, and find the latter are subject to larger uncertainties. These results indicate that spatially resolved observations are critical for probing AGN feedback on scales where circumnuclear star formation occurs.
Pure Neutron Matter Constraints and Nuclear Symmetry Energy

In this review, we will discuss the results of our recent work [1] to study the general optimization of the pure isovector parameters of the popular relativistic mean-field (RMF) and Skyrme-Hartree-Fock (SHF) nuclear energy-density functionals (EDFs), using constraints on the pure neutron matter (PNM) equation of state (EoS) from recent ab initio calculations. By using RMF and SHF parameterizations that give equivalent predictions for ground-state properties of doubly magic nuclei and properties of symmetric nuclear matter (SNM) and PNM, we found that such optimization leads to broadly consistent symmetry energy J and its slope parameter L at saturation density within a tight range of α(J) < 2 MeV and α(L) < 6 MeV. We demonstrate that a clear model dependence shows up (a) in the curvature parameter of the symmetry energy Ksym, (b) the symmetry energy at supra-saturation densities, and (c) the radius of neutron stars.
Non-factorizable terms, heavy quark masses, and semileptonic decays of D and B mesons

The non-factorizable terms in the operator product expansion have been recognized as one of the theoretical obstacles for precision determination of the mixing parameter Vub from semileptonic B decays. It is pointed out here that the recent CLEO data on the parameters of the heavy quark expansion λ1 and ${\bar \Lambda}$, combined with a theoretical bound on λ1 strongly favor the existence of a sizeable contribution of non-factorizable terms in semileptonic decays of D mesons. Thus these terms are likely to solve the long-standing problem of the deficit of semileptonic decay rate of the D mesons, and with better data their magnitude can be determined and used in studies of the parameter Vub.
Excitation dependence of resonance line self-broadening at different atomic densities

We study the dipole?dipole spectral broadening of a resonance line at high atomic densities when the self-broadening dominates. The selective reflection spectrum of a weak probe beam from the interface of the cell window and rubidium vapour is recorded in the presence of a far-detuned pump beam. The excitation due to the pump reduces the self-broadening. We found that the self-broadening reduction dependence on the pump power is atomic density independent. These results provide experimental evidence for the disordered exciton based theory of self-broadening, and can be useful for the description of the interaction of a strong optical field with a dense resonance medium.
How do Type Ia Supernova Nebular Spectra Depend on Explosion Properties? Insights from Systematic non-LTE Modeling

We present a radiative transfer code to model the nebular phase spectra of supernovae (SNe) in non-local thermodynamic equilibrium (NLTE). We apply it to a systematic study of Type Ia SNe using parameterized 1D models and show how nebular spectral features depend on key physical parameters, such as the time since explosion, total ejecta mass, kinetic energy, radial density profile, and the masses of 56Ni, intermediate mass elements (IMEs), and stable iron-group elements (IGEs). We also quantify the impact of uncertainties in atomic data inputs. Among the results of the study are: (1) The main features of SNe Ia nebular spectra are relatively insensitive to most physical parameters. Degeneracy among parameters precludes a unique determination of the ejecta properties from spectral fitting. In particular, features can be equally well fit with generic Chandrasekhar mass (M_ch), sub-M_Ch, and super-M_Ch models; (2) A sizable (~0.1 Msun) central region of stable IGEs, often claimed as evidence for M_Ch models, is not essential to fit the optical spectra and may produce an unusual flat-top [CoIII] profile; (3) The strength of [SIII] emission near 9500A can provide a useful diagnostic of explosion nucleosynthesis; (4) Substantial amounts (~0.1 Msun) of unburned C/O mixed throughout the ejecta produce [OIII] emission not seen in observations; (5) Shifts in the wavelength of line peaks, sometimes used to infer ejecta geometry, can also arise from line blending effects; (6) The steepness of the ejecta density profile affects the line shapes, with flatter slopes providing better fits to the observations of SN 2011fe, offering a constraint on explosion models; (7) Uncertainties in atomic data affect spectral line ratios by ~30%, a level similar to the effect of varying physical parameters.
A Search for Neutrinos from Fast Radio Bursts with IceCube

We present a search for neutrinos in coincidence in time and direction with four fast radio bursts (FRBs) detected by the Parkes and Green Bank radio telescopes during the first year of operation of the complete IceCube Neutrino Observatory (2011 May through 2012 May). The neutrino sample consists of 138,322 muon neutrino candidate events, which are dominated by atmospheric neutrinos and atmospheric muons but also contain an astrophysical neutrino component. Considering only neutrinos detected on the same day as each FRB, zero IceCube events were found to be compatible with the FRB directions within the estimated 99% error radius of the neutrino directions. Based on the non-detection, we present the first upper limits on the neutrino fluence from FRBs.
The Supremum Norm of the Discrepancy Function: Recent Results and Connections

A great challenge in the analysis of the discrepancy function D N is to obtain universal lower bounds on the L ∞ norm of D N in dimensions d ≥ 3. It follows from the L 2 bound of Klaus Roth that \(\Vert D_{N}\Vert _{\infty }\geq \Vert D_{N}\Vert _{2} \gtrsim {(\log N)}^{(d-1)/2}\). It is conjectured that the L ∞ bound is significantly larger, but the only definitive result is that of Wolfgang Schmidt in dimension d = 2. Partial improvements of the Roth exponent (d − 1)∕2 in higher dimensions have been established by the authors and Armen Vagharshakyan. We survey these results, the underlying methods, and some of their connections to other subjects in probability, approximation theory, and analysis.
The Physical Nature of Starburst-driven Galactic Outflows

We present the fourth of the Cholla Galactic OutfLow Simulations suite (CGOLS). Using a physically-motivated prescription for clustered supernova feedback, we successfully drive a multiphase outflow from a disk galaxy. The high resolution ($< 5\,\mathrm{pc}$) across a relatively large domain ($20\,\mathrm{kpc}$) allows us to capture the hydrodynamic mixing and dynamical interactions between the hot and cool ($T \sim 10^4\,\mathrm{K}$) phases in the outflow, which in turn leads to direct evidence of a qualitatively new mechanism for cool gas acceleration in galactic winds. We show that mixing of momentum from the hot phase to the cool phase accelerates the cool gas to $800\,\mathrm{km}\,\mathrm{s}^{-1}$ on kpc scales, with properties inconsistent with the physical models of ram pressure acceleration or with bulk cooling from the hot phase. The mixing process also affects the hot phase, modifying its radial profiles of temperature, density, and velocity from the expectations of radial supersonic flow. This mechanism provides a physical explanation for the high velocity, blue shifted, low ionization absorption lines often observed in the spectra of starburst and high redshift galaxies.
Asymmetric concentration dependence of segregation fluxes in granular flows

Particles differing in size or density segregate in dense granular flows. In bidisperse mixtures, the sinking (small or heavy) species concentration that maximizes the segregation flux is $l50%$ and decreases with increasing size or density ratio, matching a classic kinetic-sieving model.
Weak lensing power spectra for precision cosmology: Multiple-deflection, reduced shear and lensing bias corrections

It is usually assumed that the ellipticity power spectrum measured in weak lensing observations can be expressed as an integral over the underlying matter power spectrum. This is true at order O(Φ^2) in the gravitational potential. We extend the standard calculation, constructing all corrections to order O(Φ^4). There are four types of corrections: corrections to the lensing shear due to multiple-deflections; corrections due to the fact that shape distortions probe the reduced shear γ/(1 − κ) rather than the shear itself; corrections associated with the non-linear conversion of reduced shear to mean ellipticity; and corrections due to the fact that observational galaxy selection and shear measurement is based on galaxy brightnesses and sizes which have been (de)magnified by lensing. We show how the previously considered corrections to the shear power spectrum correspond to terms in our analysis, and highlight new terms that were not previously identified. All correction terms are given explicitly as integrals over the matter power spectrum, bispectrum, and trispectrum, and are numerically evaluated for the case of sources at z = 1. We find agreement with previous works for the O(Φ^3) terms. We find that for ambitious future surveys, the O(Φ^4) terms affect the power spectrum at the ~1−5σ level; they will thus need to be accounted for, but are unlikely to represent a serious difficulty for weak lensing as a cosmological probe.
Why Does Deep and Cheap Learning Work So Well

We show how the success of deep learning could depend not only on mathematics but also on physics: although well-known mathematical theorems guarantee that neural networks can approximate arbitrary functions well, the class of functions of practical interest can frequently be approximated through “cheap learning” with exponentially fewer parameters than generic ones. We explore how properties frequently encountered in physics such as symmetry, locality, compositionality, and polynomial log-probability translate into exceptionally simple neural networks. We further argue that when the statistical process generating the data is of a certain hierarchical form prevalent in physics and machine learning, a deep neural network can be more efficient than a shallow one. We formalize these claims using information theory and discuss the relation to the renormalization group. We prove various “no-flattening theorems” showing when efficient linear deep networks cannot be accurately approximated by shallow ones without efficiency loss; for example, we show that n variables cannot be multiplied using fewer than $$2^n$$ neurons in a single hidden layer.
An Alternative Model of the Magnetic Cataclysmic Variable V1432 Aquilae (=RX J1940.1–1025)

V1432 Aql is currently considered to be an asynchronous AM Her type system, with an orbital period of 12,116.3 s and a spin period of 12,150 s. I present an alternative model in which V1432 Aql is an intermediate polar with disk overflow or diskless accretion geometry, with a spin period near 4040 s. I argue that published data are insufficient to distinguish between the two models; instead, I provide a series of predictions of the two models that can be tested against future observations.
Multimodal Routing: Improving Local and Global Interpretability of Multimodal Language Analysis.

The human language can be expressed through multiple sources of information known as modalities, including tones of voice, facial gestures, and spoken language. Recent multimodal learning with strong performances on human-centric tasks such as sentiment analysis and emotion recognition are often black-box, with very limited interpretability. In this paper we propose, which dynamically adjusts weights between input modalities and output representations differently for each input sample. Multimodal routing can identify relative importance of both individual modalities and cross-modality factors. Moreover, the weight assignment by routing allows us to interpret modality-prediction relationships not only globally (i.e. general trends over the whole dataset), but also locally for each single input sample, meanwhile keeping competitive performance compared to state-of-the-art methods.
Linear and nonlinear rogue wave statistics in the presence of random currents

We review recent progress in modelling the probability distribution of wave heights in the deep ocean as a function of a small number of parameters describing the local sea state. Both linear and nonlinear mechanisms of rogue wave formation are considered. First, we show that when the average wave steepness is small and nonlinear wave effects are subleading, the wave height distribution is well explained by a single 'freak index' parameter, which describes the strength of (linear) wave scattering by random currents relative to the angular spread of the incoming random sea. When the average steepness is large, the wave height distribution takes a very similar functional form, but the key variables determining the probability distribution are the steepness, and the angular and frequency spread of the incoming waves. Finally, even greater probability of extreme wave formation is predicted when linear and nonlinear effects are acting together.
Strategies for detecting the missing hot baryons in the universe

About 30% to 50% of the baryons in the local universe are unaccounted for and are likely in a hot phase, 105.5 to 108 K. A hot halo (106.3 K) is detected around the Milky Way through the O VII and O VIII resonance absorption and emission lines in the soft x-ray band. Current instruments are not sensitive enough to detect this gas in absorption around other galaxies and galaxy groups, the two most likely sites. We show that resonant line absorption by this hot gas can be detected with current technology, with a collecting area exceeding ∼300 cm2 and a spectral resolution R>2000. For a few notional x-ray telescope configurations that could be constructed as Explorer or Probe missions, we calculate the differential number of O VII and O VIII absorbers as a function of equivalent width through redshift space, dN/dz. The hot halos of individual external galaxies produce absorption that should be detectable out to about their virial radii. For the Milky Way, one can determine the radial distribution of density, temperature, and metallicity after making optical depth corrections. Spectroscopic observations can determine the rotation of a hot gaseous halo.
Gluing Semiclassical Resolvent Estimates via Propagation of Singularities

We use semiclassical propagation of singularities to give a general method for gluing together resolvent estimates. As an application we prove estimates for the analytic continuation of the resolvent of a Schroedinger operator for certain asymptotically hyperbolic manifolds in the presence of trapping which is sufficiently mild in one of several senses. As a corollary we obtain local exponential decay for the wave propagator and local smoothing for the Schroedinger propagator. This project is joint work with Andras Vasy.
Quantum Monte Carlo with variable spins

We investigate the inclusion of variable spins in electronic structure quantum Monte Carlo, with a focus on diffusion Monte Carlo with Hamiltonians that include spin-orbit interactions. Following our previous introduction of fixed-phase spin-orbit diffusion Monte Carlo, we thoroughly discuss the details of the method and elaborate upon its technicalities. We present a proof for an upper-bound property for complex nonlocal operators, which allows for the implementation of T-moves to ensure the variational property. We discuss the time step biases associated with our particular choice of spin representation. Applications of the method are also presented for atomic and molecular systems. We calculate the binding energies and geometry of the PbH and Sn2 molecules, as well as the electron affinities of the 6p row elements in close agreement with experiments.
Computational Mechanics of Input–Output Processes: Structured Transformations and the \(\epsilon \)-Transducer

Computational mechanics quantifies structure in a stochastic process via its causal states, leading to the process’s minimal, optimal predictor—the \(\epsilon {\text {-}}\mathrm{machine}\). We extend computational mechanics to communication channels coupling two processes, obtaining an analogous optimal model—the \(\epsilon {\text {-}}\mathrm{transducer}\)—of the stochastic mapping between them. Here, we lay the foundation of a structural analysis of communication channels, treating joint processes and processes with input. The result is a principled structural analysis of mechanisms that support information flow between processes. It is the first in a series on the structural information theory of memoryful channels, channel composition, and allied conditional information measures.
Counting Schur rings over cyclic groups

Any Schur ring is uniquely determined by a partition of the elements of the group. An open question in the study of Schur rings is determining which partitions of the group induce a Schur ring. Although a structure theorem is available for Schur rings over cyclic groups, it is still a difficult problem to count all the partitions. For example, Kovacs, Liskovets, and Poschel determine formulas to count the number of wreath-indecomposable Schur rings. In this paper, we solve the problem of counting the number of all Schur rings over cyclic groups of prime power order and draw some parallels with Higman’s PORC conjecture.
Computing for the DUNE Long-Baseline Neutrino Oscillation Experiment

This paper is based on a talk given at Computing in High Energy Physics in Adelaide, South Australia, Australia in November 2019. It is partially intended to explain the context of DUNE Computing for computing specialists.The Deep Underground Neutrino Experiment (DUNE) collaboration consists of over 180 institutions from 33 countries. The experiment is in preparation now, with commissioning of the first 10kT fiducial volume Liquid Argon TPC expected over the period 2025-2028 and a long data taking run with 4 modules expected from 2029 and beyond.An active prototyping program is already in place with a short test-beam run with a 700T, 15,360 channel prototype of single-phase readout at the Neutrino Platform at CERN in late 2018 and tests of a similar sized dual-phase detector scheduled for mid-2019. The 2018 test-beam run was a valuable live test of our computing model. The detector produced raw data at rates of up to 2GB/s. These data were stored at full rate on tape at CERN and Fermilab and replicated at sites in the UK and Czech Republic. In total 1.2 PB of raw data from beam and cosmic triggers were produced and reconstructed during the six week testbeam run.Baseline predictions for the full DUNE detector data, starting in the late 2020’s are 30-60 PB of raw data per year. In contrast to traditional HEP computational problems, DUNE’s Liquid Argon TPC data consist of simple but very large (many GB) 2D data objects which share many characteristics with astrophysical images. This presents opportunities to use advances in machine learning and pattern recognition as a frontier user of High Performance Computing facilities capable of massively parallel processing.
Extensionless Adaptive Transmitter and Receiver Windowing of Beyond 5G Frames

Newer cellular communication generations are planned to allow asynchronous transmission of multiple numerologies (waveforms with different parameters) in adjacent bands, creating unavoidable adjacent channel interference. Most prior work on windowing assume additional extensions reserved for windowing, which does not comply with standards. Whether windowing should be applied at the transmitter or the receiver was not questioned. In this work, we propose two independent algorithms that are implemented at the transmitter and receiver, respectively. These algorithms estimate the transmitter and receiver windowing duration of each resource element (RE) with an aim to improve fair proportional network throughput. While doing so, we solely utilize the available extension that was defined in the standard and present standard-compliant algorithms that also do not require any modifications on the counterparts or control signaling. Furthermore, computationally efficient techniques to apply per-RE transmitter and receiver windowing to signals synthesized and analyzed using conventional cyclic prefix-orthogonal frequency division multiplexing are derived and their computational complexities are analyzed. The spectrotemporal relations between optimum window durations at either side, as well as functions of the excess signal-to-noise ratios, the subcarrier spacings and the throughput gains provided over previous similar techniques are numerically verified.
The Plebanski sectors of the EPRL vertex

Modern spin-foam models of four-dimensional gravity are based on a discrete version of the Spin(4) Plebanski formulation. Beyond what is already in the literature, we clarify the meaning of different Plebanski sectors in this classical discrete model. We show that the linearized simplicity constraint used in the EPRL and FK models are not sufficient to impose a restriction to a single Plebanski sector, but rather, three Plebanski sectors are mixed. We propose this as the reason for certain extra 'undesired' terms in the asymptotics of the EPRL vertex analyzed by Barrett et al. This explanation for the extra terms is new and different from that sometimes offered in the spin-foam literature thus far.
Convective instabilities of bunched beams with space charge

For a single hadron bunch in a circular accelerator at zero chromaticity, without multiturn wakes and without electron clouds and other beams, only one transverse collective instability is possible, the mode-coupling instability (TMCI). For sufficiently strong space charge (SC), the instability threshold of the wake-driven coherent tune shift normally increases linearly with the SC tune shift, as independently concluded by several authors using different methods. This stability condition has, however, a very strange feature: at strong SC, it is totally insensitive to the number of particles. Thus, were it correct, such a beam with sufficiently strong SC, being stable at some intensity, would remain stable at higher intensity, regardless of how much higher. This paper suggests a resolution of this conundrum: while SC suppresses the TMCI, it introduces head-to-tail convective amplifications, which could make the beam even less stable than without SC, even if all the coherent tunes are real, i.e., all the modes are stable in the conventional absolute meaning of the word. This is done using an effective new method of analysis of the beam's transverse spectrum for arbitrary space charge and wake fields. Two new types of beam instabilities are introduced: the saturating convective instability and the absolute-convective instability.
Allosteric interactions in a birod model of DNA

Allosteric interactions between molecules bound to DNA at distant locations have been known for a long time. The phenomenon has been studied via experiments and numerical simulations, but a comprehensive understanding grounded in a theory of DNA elasticity remains a challenge. Here, we quantify allosteric interactions between two entities bound to DNA by using the theory of birods. We recognize that molecules bound to DNA cause local deformations that can be captured in a birod model which consists of two elastic strands interacting via an elastic web representing the basepairs. We show that the displacement field caused by bound entities decays exponentially with distance from the binding site. We compute the interaction energy between two proteins on DNA as a function of distance between them and find that it decays exponentially while oscillating with the periodicity of the double helix, in excellent agreement with experiments. The decay length of the interaction energy can be determined in terms of the mechanical properties of the strands and the webbing in our birod model, and it varies with the GC content of the DNA. Our model provides a framework for viewing allosteric interactions in DNA within the ambit of configurational forces of continuum elasticity.
Complex nonlinear capacitance in outer hair cell macro-patches: effects of membrane tension.

Outer hair cell (OHC) nonlinear capacitance (NLC) represents voltage sensor charge movements of prestin (SLC26a5), the protein responsible for OHC electromotility. Previous measures of NLC frequency response have employed methods which did not assess the influence of dielectric loss (sensor charge movements out of phase with voltage) that may occur, and such loss conceivably may influence prestin’s frequency dependent activity. Here we evaluate prestin’s complex capacitance out to 30 kHz and find that prestin’s frequency response determined using this approach coincides with all previous estimates. We also show that membrane tension has no effect on prestin’s frequency response, despite substantial shifts in its voltage operating range, indicating that prestin transition rate alterations do not account for the shifts. The magnitude roll-off of prestin activity across frequency surpasses the reductions of NLC caused by salicylate treatments that are known to abolish cochlear amplification. Such roll-off likely limits the effectiveness of prestin in contributing to cochlear amplification at the very high acoustic frequencies processed by some mammals.
Fluctuating hydrodynamics of electrolytes at electroneutral scales

Author(s): Donev, A; Nonaka, AJ; Kim, C; Garcia, AL; Bell, JB | Abstract: At mesoscopic scales electrolyte solutions are modeled by the fluctuating generalized Poisson-Nernst-Planck (PNP) equations [J.-P. Peraud, Phys. Rev. Fluids 1, 074103 (2016)2469-990X10.1103/PhysRevFluids.1.074103]. However, at length and time scales larger than the Debye scales, electrolytes are effectively electroneutral and the charged-fluid PNP equations become too stiff to solve numerically. Here we formulate the isothermal incompressible equations of fluctuating hydrodynamics for reactive multispecies mixtures involving charged species in the electroneutral limit and design a numerical algorithm to solve these equations. Our model does not assume a dilute electrolyte solution but rather treats all species on an equal footing, accounting for cross diffusion and nonideality using Maxwell-Stefan theory. By enforcing local electroneutrality as a constraint, we obtain an elliptic equation for the electric potential that replaces the Poisson equation in the fluctuating PNP equations. We develop a second-order midpoint predictor-corrector algorithm to solve either the charged-fluid or electroneutral equations with only a change of the elliptic solver. We use the electroneutral algorithm to study a gravitational fingering instability, triggered by thermal fluctuations, at an interface where an acid and base react to neutralize each other. Our results demonstrate that, because the four ions diffuse with very different coefficients, one must treat each ion as an individual species and cannot treat the acid, base, and salt as neutral species. This emphasizes the differences between electrodiffusion and classical Fickian diffusion, even at electroneutral scales.
Minimax sparse principal subspace estimation in high dimensions

We study sparse principal components analysis in high dimensions, where $p$ (the number of variables) can be much larger than $n$ (the number of observations), and analyze the problem of estimating the subspace spanned by the principal eigenvectors of the population covariance matrix. We introduce two complementary notions of $\ell_{q}$ subspace sparsity: row sparsity and column sparsity. We prove nonasymptotic lower and upper bounds on the minimax subspace estimation error for $0\leq q\leq1$. The bounds are optimal for row sparse subspaces and nearly optimal for column sparse subspaces, they apply to general classes of covariance matrices, and they show that $\ell_{q}$ constrained estimates can achieve optimal minimax rates without restrictive spiked covariance conditions. Interestingly, the form of the rates matches known results for sparse regression when the effective noise variance is defined appropriately. Our proof employs a novel variational $\sin\Theta$ theorem that may be useful in other regularized spectral estimation problems.
Phenomenology of bulk scalar singlets in the Randall-Sundrum model

We present a Randall–Sundrum toy model with an added scalar singlet that couples only to KK fermions in the bulk. Such a scalar would nontrivially affect radion phenomenology. In addition, we examine the radion phenomenology in light of the new scalar and show how this scalar could present another probe to search for the radion.
Asymptotic symmetries of Yang-Mills theory

Asymptotic symmetries at future null infinity ( $$ \mathrm{\mathcal{I}} $$ +) of Minkowski space for electrodynamics with massless charged fields, as well as nonabelian gauge theories with gauge group G, are considered at the semiclassical level. The possibility of charge/color flux through $$ \mathrm{\mathcal{I}} $$ + suggests the symmetry group is infinite-dimensional. It is conjectured that the symmetries include a G Kac-Moody symmetry whose generators are “large” gauge transformations which approach locally holomorphic functions on the conformal two-sphere at $$ \mathrm{\mathcal{I}} $$ + and are invariant under null translations. The Kac-Moody currents are constructed from the gauge field at the future boundary of $$ \mathrm{\mathcal{I}} $$ +. The current Ward identities include Weinberg’s soft photon theorem and its colored extension.
A Categorical Approach to Groupoid Frobenius Algebras

In this paper, we show that \(\mathcal{G}\)-Frobenius algebras (for \(\mathcal{G}\) a finite groupoid) correspond to a particular class of Frobenius objects in the representation category of \(D(k[\mathcal{G}])\), where \(D(k[\mathcal{G}])\) is the Drinfeld double of the quantum groupoid \(k[\mathcal{G}]\) (Nikshych et al. 2000).
Atomistic modeling of interfacial segregation and structural transitions in ternary alloys

Grain boundary engineering via dopant segregation can dramatically change the properties of a material. For metallic systems, most current studies concerning interfacial segregation and subsequent transitions of grain boundary structure are limited to binary alloys, yet many important alloy systems contain more than one type of dopant. In this work, hybrid Monte Carlo/molecular dynamics simulations are performed to investigate the behavior of dopants at interfaces in two model ternary alloy systems: Cu–Zr–Ag and Al–Zr–Cu. Trends in boundary segregation are studied, as well as the propensity for the grain boundary structure to become disordered at high temperature and doping concentration. For Al–Zr–Cu, we find that the two solutes prefer to occupy different sites at the grain boundary, leading to a synergistic doping effect. Alternatively, for Cu–Zr–Ag, there is site competition because the preferred segregation sites are the same. Finally, we find that thicker amorphous intergranular films can be formed in ternary systems by controlling the concentration ratio of different solute elements.
Gyrator Operation Using Josephson Mixers

Nonreciprocal devices such as circulators function as one-way gates for microwave light, and thus are necessary components in superconducting quantum circuitry. However, today's circulators are bulky, lossy, and employ strong magnetic fields, and thus incompatible with scaling up. A proof-of-principle experiment demonstrates gyration in a Josephson circuit, in which microwave signals traveling in opposite directions acquire a 180\ifmmode^\circ\else\textdegree\fi{} phase difference. Inserting this gyrator into one arm of a Mach-Zehnder interferometer would enable a lossless, on-chip circulator with no magnetic materials, which could be used in a variety of applications for quantum information processing.
Dynamics of matter-wave quantum emitters in a structured vacuum

The authors study the dynamics of matter-wave quantum emitters coupled to the band structure of a periodic potential, in which bound states involving evanescent matter waves drive a transition from exponential decay to fully reversible oscillations.
Center of mass velocity from mass polariton solution to Abraham-Minkowski controversy

Abstract A one-hundred-year old controversy, the Abraham-Minkowski controversy, concerns two widely disparate predictions for the momentum of light in glass. In the Abraham case the photon momentum is inversely proportional to the index of refraction while the photon momentum predicted by Minkowski formulation is proportional to the index of refraction. In spite of significant theoretical and experimental effort neither formulation could convincingly be shown to be correct. A new model, called the Mass Polariton model, MP, was recently introduced that resolves the contradictions in the Abraham and Minkowski formulations and experimental results. Both the MP and Minkowski model predict the same momentum change for a photon entering glass from a vacuum, yet the Minkowski model allows violation of the center of mass theorem. This paper shows that the MP model, in spite of predicting the same momentum change as the Minkowski model, obeys the center of mass theorem.
Comparing narrative-informed occupational therapy in adult outpatient mental health to treatment as usual: A quasi-experimental feasibility study with preliminary treatment outcomes.

This paper describes implementation of narrative-informed occupation-based service delivery in outpatient community mental health that addresses (1) the need for outcome data on occupational therap...
Persistent Heart Failure Symptoms at Hospital Discharge Predicts 30-Day Clinical Events.

Background The relationship between heart failure (HF) symptoms at hospital discharge and 30-day clinical events is unknown. Variability in HF symptom assessment may affect ability to predict readmission risk. Objective The aim of this study was to describe HF symptom profiles and burden at hospital discharge. A secondary aim was to examine the relationship between symptom burden at discharge and 30-day clinical events. Methods An exploratory descriptive design was used. Patients with HF (n = 186) were enrolled 24 to 48 hours pre hospital discharge. The HF Somatic Perception Scale quantified 18 HF physical signs and symptoms. Scores were divided into tertiles (0-10, 11-19, and 20 and higher). The Patient Health Questionnaire-9 quantified depressive symptoms. Self-assessed health, comorbid illnesses, and 30-day clinical events were documented. Chi-square and logistic regression were used to examine clinical events. Results The sample (n = 186) was predominantly White (87.6%), male (59.1%), elderly (mean [SD], 74.2 [12.5]), and symptomatic (92.5%) at discharge. Heart Failure Somatic Perception Scale scores ranged from 0 to 53, with a mean (SD) of 13.7 (10.1). Symptoms reported most frequently were fatigue (67%), nocturia (62%), need to rest (53%), and inability to do usual activities due to shortness of breath (52%). Thirty-day event rate was 28%, with significant differences between Heart Failure Somatic Perception Scale tertiles (9.4% vs 37.7% in the second and third tertiles, respectively; [chi]22(N = 186) = 16.73, P < .001). Heart Failure Somatic Perception Scale tertile 2 or 3 (odds ratio [OR], 5.7; P = .003; and OR, 4.3; P = .021), self-assessed health (OR, 2.6; P = .029), and being in a relationship predicted clinical events. Conclusions Heart failure symptom burden at discharge predicted 30-day clinical events. Comprehensive symptom assessment is important when determining readmission risk.
Fault-tolerant quantum error correction for Steane’s seven-qubit color code with few or no extra qubits

Steane's seven-qubit quantum code is a natural choice for fault-tolerance experiments because it is small and just two extra qubits are enough to correct errors. However, the two-qubit error-correction technique, known as "flagged" syndrome extraction, works slowly, measuring only one syndrome at a time. This is a disadvantage in experiments with high qubit rest error rates. We extend the technique to extract multiple syndromes at once, without needing more qubits. Qubits for different syndromes can flag errors in each other. This gives equally fast and more qubit-efficient alternatives to Steane's error-correction method, and also conforms to planar geometry constraints. We further show that Steane's code and some others can be error-corrected with no extra qubits, provided there are at least two code blocks. The rough idea is that two seven-qubit codewords can be temporarily joined into a twelve-qubit code, freeing two qubits for flagged syndrome measurement.
Learning for Microrobot Exploration: Model-based Locomotion, Sparse-robust Navigation, and Low-power Deep Classification

Building intelligent autonomous systems at any scale is challenging. The sensing and computation constraints of a microrobot platform make the problems harder. We present improvements to learning-based methods for on-board learning of locomotion, classification, and navigation of microrobots. We show how simulated locomotion can be achieved with model-based reinforcement learning via on-board sensor data distilled into control. Next, we introduce a sparse, linear detector and a Dynamic Thresholding method to FAST Visual Odometry for improved navigation in the noisy regime of mm scale imagery. We end with a new image classifier capable of classification with fewer than one million multiply-and-accumulate (MAC) operations by combining fast downsampling, efficient layer structures and hard activation functions. These are promising steps toward using state-of-the-art algorithms in the power-limited world of edge-intelligence and microrobots.
Variation of Tamagawa numbers of Jacobians of hyperelliptic curves with semistable reduction

Abstract We study how Tamagawa numbers of Jacobians of hyperelliptic curves vary as one varies the base field or the curve, in the case of semistable reduction. We find that there are strong constraints on the behaviour that appears, some of which are unexpected and specific to hyperelliptic curves. Our methods are explicit and allow one to write down formulae for Tamagawa numbers of infinite families of hyperelliptic curves, of the kind used in proofs of the parity conjecture for Jacobians of curves of small genus.
BERT-GT: Cross-sentence n-ary relation extraction with BERT and graph transformer.

Motivation A biomedical relation statement is commonly expressed in multiple sentences and consists of many concepts, including gene, disease, chemical, and mutation. To automatically extract information from biomedical literature, existing biomedical text-mining approaches typically formulate the problem as a cross-sentence n-ary relation-extraction task that detects relations among n entities across multiple sentences, and use either a graph neural network (GNN) with long short-term memory (LSTM) or an attention mechanism. Recently, Transformer has been shown to outperform LSTM on many natural language processing (NLP) tasks. Results In this work, we propose a novel architecture that combines Bidirectional Encoder Representations from Transformers with Graph Transformer (BERT-GT), through integrating a neighbor-attention mechanism into the BERT architecture. Unlike the original Transformer architecture, which utilizes the whole sentence(s) to calculate the attention of the current token, the neighbor-attention mechanism in our method calculates its attention utilizing only its neighbor tokens. Thus, each token can pay attention to its neighbor information with little noise. We show that this is critically important when the text is very long, as in cross-sentence or abstract-level relation-extraction tasks. Our benchmarking results show improvements of 5.44% and 3.89% in accuracy and F1-measure over the state-of-the-art on n-ary and chemical-protein relation datasets, suggesting BERT-GT is a robust approach that is applicable to other biomedical relation extraction tasks or datasets. Availability and implementation the source code of BERT-GT will be made freely available at https://github.com/ncbi-nlp/bert_gt upon publication.