cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultracold Rydberg molecules

Ultracold molecules formed from association of a single Rydberg atom with surrounding atoms or molecules and those from double Rydberg excitations are discussed in this review. Ultralong-range Rydberg molecules possess a novel molecular bond resulting from scattering of the Rydberg electron from the perturber atoms or molecules. The strong interactions between Rydberg atoms in ultracold gases may lead to formation of macroscopic Rydberg macrodimers. The exquisite control over the properties of the Rydberg electron means that interesting and unusual few-body and quantum many-body features can be realized in such systems.
Theory of coupled ion-electron transfer kinetics

Abstract The microscopic theory of chemical reactions is based on transition state theory, where atoms or ions transfer classically over an energy barrier, as electrons maintain their ground state. Electron transfer is fundamentally different and occurs by tunneling in response to solvent fluctuations. Here, we develop the theory of coupled ion-electron transfer, in which ions and solvent molecules fluctuate cooperatively to facilitate non-adiabatic electron transfer. We derive a general formula of the reaction rate that depends on the overpotential, solvent properties, the electronic structure of the electron donor/acceptor, and the excess chemical potential of ions in the transition state. For Faradaic reactions, the theory predicts curved Tafel plots with a concentration-dependent reaction-limited current. For moderate overpotentials, our formula reduces to the Butler–Volmer equation and explains its relevance, not only in the well-known limit of large electron-transfer (solvent reorganization) energy, but also in the opposite limit of large ion-transfer energy. The rate formula is applied to Li-ion batteries, where reduction of the electrode host material couples with ion insertion. In the case of lithium iron phosphate, the theory accurately predicts the concentration dependence of the exchange current measured by in operando X-Ray microscopy without any adjustable parameters. These results pave the way for interfacial engineering to enhance ion intercalation rates, not only for batteries, but also for ionic separations and neuromorphic computing.
When clusters collide: constraints on antimatter on the largest scales

Observations have ruled out the presence of significant amounts of antimatter in the Universe on scales ranging from the solar system, to the Galaxy, to groups and clusters of galaxies, and even to distances comparable to the scale of the present horizon. Except for the model-dependent constraints on the largest scales, the most significant upper limits to diffuse antimatter in the Universe are those on the ~Mpc scale of clusters of galaxies provided by the EGRET upper bounds to annihilation gamma rays from galaxy clusters whose intracluster gas is revealed through its x-ray emission. On the scale of individual clusters of galaxies the upper bounds to the fraction of mixed matter and antimatter for the 55 clusters from a flux-limited x-ray survey range from 5 × 10−9 to <1 × 10−6, strongly suggesting that individual clusters of galaxies are made entirely of matter or of antimatter. X-ray and gamma-ray observations of colliding clusters of galaxies, such as the Bullet Cluster, permit these constraints to be extended to even larger scales. If the observations of the Bullet Cluster, where the upper bound to the antimatter fraction is found to be <3 × 10−6, can be generalized to other colliding clusters of galaxies, cosmologically significant amounts of antimatter will be excluded on scales of order ~20 Mpc ().
Beltrami–Courant differentials and $G_{\infty}$-algebras

Using the symmetry properties of two-dmensional sigma models, we introduce a notion of the Beltrami-Courant differential, so that there is a natural homotopy Gerstenhaber algebra related to it. We conjecture that the generalized Maurer-Cartan equation for the corresponding $L_{\infty}$ subalgebra gives solutions to the Einstein equations.
Scattering of a dark─bright soliton by an impurity

We study the dynamics of a dark-bright soliton interacting with a fixed impurity using a mean-field approach. The system is described by a vector nonlinear Schrodinger equation (NLSE) appropriate to multicomponent Bose-Einstein condensates. We use the variational approximation, based on hyperbolic functions, where we have the center of mass of the two components to describe the propagation of the dark and bright components independently. Therefore, it allows the dark-bright soliton to oscillate. The fixed local impurity is modeled by a delta function. Also, we use perturbation methods to derive the equations of motion for the center of mass of the two components. The interaction of the dark-bright soliton with a delta function potential excites different modes in the system. The analytical model capture two of these modes: the relative oscillation between the two components and the oscillation in the widths. The numerical simulations show additional internal modes play an important role in the interaction problem. The excitation of internal modes corresponds to inelastic scattering. In addition, we calculate the maximum velocity for a dark-bright soliton and find it is limited to a value below the sound speed, depending on the relative number of atoms present in the bright soliton component and excavated by the dark soliton component, respectively. Above a critical value of the maximum velocity, the two components are no longer described by one center of mass variable and develop internal oscillations, eventually breaking apart when pushed to higher velocities. This effect limits the incident kinetic energy in scattering studies and presents a smoking gun experimental signal.
MicroBooNE: A New Liquid Argon Time Projection Chamber Experiment

Liquid Argon Time Projection Chamber detectors are well suited to study neutrino interactions, and are an intriguing option for future massive detectors capable of measuring the parameters that characterize neutrino oscillations. These detectors combine fine‐grained tracking with calorimetry, allowing for excellent imaging and particle identification ability. In this talk the details of the MicroBooNE experiment, a 175 ton LArTPC which will be exposed to Fermilab’s Booster Neutrino Beamline starting in 2011, will be presented. The ability of MicroBooNE to differentiate electrons from photons gives the experiment unique capabilities in low energy neutrino interaction measurements.
Spatially Resolved Hopkins Ultraviolet Telescope Spectra of NGC 1068

We present spatially resolved far-ultraviolet spectra (912-1840 A) of NGC 1068 obtained using the Hopkins Ultraviolet Telescope (HUT) during the 1995 March Astro-2 mission. Three spectra of this prototypical Seyfert 2 galaxy were obtained through a 12'' diameter aperture centered on different locations near the nucleus. The first pointing (A1) was centered west of the optical nucleus; the nucleus was on the eastern edge of the aperture. The second (A2) was centered southwest of the optical nucleus with the nucleus well inside the aperture. The third (B) was centered on the ionization cone, with the nucleus on the southwestern edge of the aperture. While all three aperture locations have spectra similar to the Astro-1 observations of Kriss et al., these new spatially resolved observations localize the source of the far-UV line and continuum emission. The ionization cone (location B) has both brighter emission lines and continuum than the nuclear region (location A2). Position A1 is fainter than either A2 or B in both lines and continuum. The far-UV emission lines observed with HUT have a spatial distribution that most closely resembles that of [O III] λ5007 but appear to be more extended and offset to the northeast along the axis of the radio jet. This supports the previous conclusion of Kriss et al. that the bright C III λ977 and N III λ991 arises in shock-heated gas. The UV continuum radiation has a more extended spatial distribution than the line-emitting gas. At wavelengths longward of 1200 A, the inferred continuum distribution is consistent with that seen in archival Hubble Space Telescope WFPC2 images through filter F218W, and it appears to contain a substantial contribution from starlight. At wavelengths shorter than 1200 A, the UV continuum becomes more concentrated in a region matching the location and shape of the UV line radiation, consistent with nuclear flux scattered by a combination of the electron scattering mirror and the northeast dust cloud.
Geometry, Kinematics, and Magnetization of Simulated Prestellar Cores

We utilize the more than 100 gravitationally-bound dense cores formed in our three-dimensional, turbulent MHD simulations reported in Chen & Ostriker (2015) to analyze structural, kinematic, and magnetic properties of prestellar cores. Our statistical results disagree with the classical theory of star formation, in which cores evolve to be oblate with magnetic field parallel to the minor axes. Instead, we find that cores are generally triaxial, although the core-scale magnetic field is still preferentially most parallel to the core's minor axis and most perpendicular to the major axis. The internal and external magnetic field directions are correlated, but the direction of integrated core angular momentum is misaligned with the core's magnetic field, consistent with recent observations. The ratio of rotational/total kinetic and rotational/gravitational energies are independent of core size and consistent in magnitude with observations. The specific angular momentum also follows the observed relationship $L/M \propto R^{3/2}$, indicating rotation is acquired from ambient turbulence. With typical $E_\mathrm{rot}/E_K \sim 0.1$, rotation is not the dominant motion when cores collapse.
Effective field theory approach to trans-TeV supersymmetry: covariant matching, Yukawa unification and Higgs couplings

Dismissing traditional naturalness concerns while embracing the Higgs boson mass measurement and unification motivates careful analysis of trans-TeV supersymmetric theories. We take an effective field theory (EFT) approach, matching the Minimal Supersymmetric Standard Model (MSSM) onto the Standard Model (SM) EFT by integrating out heavy superpartners, and evolving MSSM and SMEFT parameters according to renormalization group equations in each regime. Our matching calculation is facilitated by the recent covariant diagrams formulation of functional matching techniques, with the full one-loop SUSY threshold corrections encoded in just 30 diagrams. Requiring consistent matching onto the SMEFT with its parameters (those in the Higgs potential in particular) measured at low energies, and in addition requiring unification of bottom and tau Yukawa couplings at the scale of gauge coupling unification, we detail the solution space of superpartner masses from the TeV scale to well above. We also provide detailed views of parameter space where Higgs coupling measurements have probing capability at future colliders beyond the reach of direct superpartner searches at the LHC.
Prime and semiprime quantum linear space smash products

Bosonizations of quantum linear spaces are a large class of pointed Hopf algebras that include the Taft algebras and their generalizations. We give conditions for the smash product of an associative algebra with a bosonization of a quantum linear space to be (semi)prime. These are then used to determine (semi)primeness of certain smash products with quantum affine spaces. This extends Bergen’s work on Taft algebras.
RELATION BETWEEN GLOBULAR CLUSTERS AND SUPERMASSIVE BLACK HOLES IN ELLIPTICALS AS A MANIFESTATION OF THE BLACK HOLE FUNDAMENTAL PLANE

We analyze the relation between the mass of the central supermassive black hole (M{sub BH}) and the number of globular clusters (N{sub GC}) in elliptical galaxies and bulges as a ramification of the black hole fundamental plane, the theoretically predicted and observed multi-variable correlation between M{sub BH} and bulge binding energy. Although the tightness of the M{sub BH}-N{sub GC} correlation suggests an unlikely causal link between supermassive black holes and globular clusters (GCs), such a correspondence can exhibit small scatter even if the physical relationship is indirect. We show that the relatively small scatter of the M{sub BH}-N{sub GC} relation owes to the mutual residual correlation of M{sub BH} and N{sub GC} with stellar mass when the velocity dispersion is held fixed. Thus, present observations lend evidence for feedback-regulated models in which the bulge binding energy is most important; they do not necessarily imply any 'special' connection between GCs and M{sub BH}. This raises the question of why N{sub GC} traces the formation of ellipticals and bulges sufficiently well to be correlated with binding energy.
Robust statistics for image deconvolution

Abstract We present a blind multiframe image-deconvolution method based on robust statistics. The usual shortcomings of iterative optimization of the likelihood function are alleviated by minimizing the M -scale of the residuals, which achieves more uniform convergence across the image. We focus on the deconvolution of astronomical images, which are among the most challenging due to their huge dynamic ranges and the frequent presence of large noise-dominated regions in the images. We show that high-quality image reconstruction is possible even in super-resolution and without the use of traditional regularization terms. Using a robust ρ -function is straightforward to implement in a streaming setting and, hence our method is applicable to the large volumes of astronomy images. The power of our method is demonstrated on observations from the Sloan Digital Sky Survey (Stripe 82) and we briefly discuss the feasibility of a pipeline based on Graphical Processing Units for the next generation of telescope surveys.
Existence of a Radner equilibrium in a model with transaction costs

We prove the existence of a Radner equilibrium in a model with proportional transaction costs on an infinite time horizon and analyze the effect of transaction costs on the endogenously determined interest rate. Two agents receive exogenous, unspanned income and choose between consumption and investing into an annuity. After establishing the existence of a discrete-time equilibrium, we show that the discrete-time equilibrium converges to a continuous-time equilibrium model. The continuous-time equilibrium provides an explicit formula for the equilibrium interest rate in terms of the transaction cost parameter. We analyze the impact of transaction costs on the equilibrium interest rate and welfare levels.
Intrinsically Quantum-Mechanical Gravity and the Cosmological Constant Problem

We propose that gravity be intrinsically quantum-mechanical, so that in the absence of quantum mechanics the geometry of the universe would be Minkowski. We show that in such a situation gravity does not require any independent quantization of its own, with it being quantized simply by virtue of its being coupled to the quantized matter fields that serve as its source. We show that when the gravitational and matter fields possess an underlying conformal symmetry, the gravitational field and fermionic matter-field zero-point fluctuations cancel each other identically. Then, when the fermions acquire mass by a dynamical symmetry breaking procedure that induces a cosmological constant in such conformal theories, the zero-point fluctuations readjust so as to cancel the induced cosmological constant identically. The zero-point vacuum problem and the cosmological constant vacuum problems thus mutually solve each other. We illustrate our ideas in a completely solvable conformal-invariant model, namely two-dimensional quantum Einstein gravity coupled to a Nambu–Jona-Lasinio self-consistent fermion.
Dark matter and naturalness

The Standard Model of particle physics is governed by Poincare symmetry, while all other symmetries, exact or approximate, are essentially dictated by theoretical consistency with the particle spectrum. On the other hand, many models of dark matter exist that rely upon the addition of new added global symmetries in order to stabilize the dark matter particle and/or achieve the correct abundance. In this work we begin a systematic exploration into truly natural models of dark matter, organized by only relativity and quantum mechanics, without the appeal to any additional global symmetries, no fine-tuning, and no small parameters. We begin by reviewing how singlet dark sectors based on spin 0 or spin $$ \frac{1}{2} $$ should readily decay, while pure strongly coupled spin 1 models have an overabun-dance problem. This inevitably leads us to construct chiral models with spin $$ \frac{1}{2} $$ particles charged under confining spin 1 particles. This leads to stable dark matter candidates that are analogs of baryons, with a confinement scale that can be naturally 𝒪(100)TeV. This leads to the right freeze-out abundance by annihilating into massless unconfined dark fermions. The minimal model involves a dark copy of SU(3) × SU(2) with 1 generation of chiral dark quarks and leptons. The presence of massless dark leptons can potentially give rise to a somewhat large value of ∆Neff during BBN. In order to not upset BBN one may either appeal to a large number of heavy degrees of freedom beyond the Standard Model, or to assume the dark sector has a lower reheat temperature than the visible sector, which is also natural in this framework. This reasoning provides a robust set of dark matter models that are entirely natural. Some are concrete realizations of the nightmare scenario in which dark matter may be very difficult to detect, which may impact future search techniques.
Nonlinear graphene metasurfaces with advanced electromagnetic functionalities

The optical nonlinear effects can provide different advanced electromagnetic functionalities, such as wave mixing and phase conjugation, which can be applied in a variety of new applications. However, these effects usually suffer from extremely weak nature and require high input intensity values in order to be excited. Interestingly, the large third order nonlinearity of graphene, along with the strong field confinement stemming from its plasmonic behavior, can be utilized to enhance several relative weak nonlinear effects at infrared (IR) and terahertz (THz) frequencies. Towards this goal, various nonlinear graphene metasurfaces are presented in this work to effectively increase the efficiency of different optical nonlinear effects and, as a result, decrease the required input intensity needed to be excited. In particular, we will show that the efficiency of four-wave mixing (FWM) can be improved by several orders of magnitude by using a nonlinear metasurface composed of patterned graphene ribbons, a dielectric interlayer, and a metallic reflector acting as substrate. We also demonstrate that the self-phase modulation (SPM) nonlinear process can be enhanced by using an alternative graphene nonlinear metasurface, operating as coherent perfect absorber, leading to a pronounced shift in the resonant frequency of the coherent perfect absorption (CPA) effect of this structure as the input intensity of the impinging incident waves is increased. This property will provide a robust mechanism to dynamically tune and switch the CPA process. Furthermore, it will be presented that strong negative reflection and refraction can be achieved by a single graphene monolayer film due to the enhancement of another nonlinear process, known as phase conjugation. This nonlinear process is envisioned to be used in the construction of a perfect imaging device with subwavelength resolution.
Exploration of Fine-Grained Parallelism for Load Balancing Eager K-truss on GPU and CPU

In this work we present a performance exploration on Eager K-truss, a linear-algebraic formulation of the K-truss graph algorithm. We address performance issues related to load imbalance of parallel tasks in symmetric, triangular graphs by presenting a fine-grained parallel approach to executing the support computation. This approach also increases available parallelism, making it amenable to GPU execution. We demonstrate our fine-grained parallel approach using implementations in Kokkos and evaluate them on an Intel Skylake CPU and an Nvidia Tesla V100 GPU. Overall, we observe between a 1.261. 48x improvement on the CPU and a 9.97-16.92x improvement on the GPU due to our fine-grained parallel formulation.
Probing Context-Dependent Errors in Quantum Processors

A new protocol benchmarks the stability of qubit-based processors, detecting whether quantum logic operations drift over time or are sensitive to crosstalk from neighboring qubits.
Choice Screen Auctions

Choice screen auctions have been recently deployed in 31 European countries, allowing consumers to choose their preferred search engine on Google's Android platform instead of being automatically defaulted to Google's own search engine. I show that a seemingly minor detail in the design of these auctions---whether they are conducted on a "per appearance" or a "per install" basis---plays a major role in the mix and characteristics of auction winners, and, consequently, in their expected overall market share. I also show that "per install" auctions distort the incentives of alternative search engines toward extracting as much revenue as possible from each user who installs them, at the expense of lowering the expected number of such users. The distortion becomes worse as the auction gets more competitive and the number of bidders increases. Empirical evidence from Android choice screen auctions conducted in 2020 is consistent with my theoretical results.
Tree-structured grid model of line and polarization variability from massive binaries

We have developed a 3-D Monte Carlo radiative transfer model which computes line and continuum polarization variability for a binary system with an optically thick non-axisymmetric envelope. This allows us to investigate the complex (phase-locked) line and continuum polarization variability features displayed by many massive binaries: W-R+O, O+O, etc. An 8-way tree data structure constructed via a \cell-splitting" method allows for high precision with ecient use of computer resources. The model is not restricted to binary systems; it can easily be adapted to a system with an arbitrary density distribution and large density gradients. As an application to a real system, the phase dependent Stokes parameters (I; Q; U) and the phase dependent He i (5876) proles of the massive binary system V444 Cyg (WN5+O6 III{V) are computed.
Tidal stretching of gravitons into classical strings: application to jet quenching with AdS/CFT

Previous work has shown that the standard supergravity approximation can break down when using AdS/CFT duality to study certain top-down formulations of the jet stopping problem in strongly-coupled $\mathcal{N}=4$ super-Yang-Mills (SYM) plasmas, depending on the virtuality of the source of the “jet.” In this paper, we identify the nature of this breakdown: High-momentum gravitons in the gravitational dual get stretched into relatively large classical string loops by tidal forces associated with the black brane. These stringy excitations of the graviton are not contained in the supergravity approximation, but we show that the jet stopping problem can nonetheless still be solved by drawing on various string-theory methods (the eikonal approximation, the Penrose limit, string quantization in pp-wave backgrounds) to obtain a probability distribution for the late-time classical string loops. In extreme cases, we find that the gravitons are stretched into very long folded strings which are qualitatively similar to the folded classical strings originally used by Gubser, Gulotta, Pufu and Rocha to model the jet stopping problem. This makes a connection in certain cases between the different methods that have been used to study jet stopping with AdS/CFT and gives a specific example of a precise $\mathcal{N}=4$ SYM problem that generates such strings in the gravity description.
A recipe for EFT uncertainty quantification in nuclear physics

The application of effective field theory (EFT) methods to nuclear systems provides the opportunity to rigorously estimate the uncertainties originating in the nuclear Hamiltonian. Yet this is just one source of uncertainty in the observables predicted by calculations based on nuclear EFTs. We discuss the goals of uncertainty quantification in such calculations and outline a recipe to obtain statistically meaningful error bars for their predictions. We argue that the different sources of theory error can be accounted for within a Bayesian framework, as we illustrate using a toy model.
Results from MINOS and NOvA

The MINOS experiment, operating in the NuMI beam since 2005, has provided the most precise measurement of the atmospheric mass splitting |Δm^2_(32)|, and the recent combination of the ν_μ, ν_e, and atmospheric neutrino samples has provided some evidence of non-maximal mixing, and hints about the neutrino mass hierarchy and the Φ_(23) octant. Construction of the NOνA experiment, situated off-axis in the upgraded NuMI beam, is almost complete. Over the coming years it will have significant power to probe the questions of the mass hierarchy, Φ _(23) octant, and the possibility of CP violation in the lepton sector. This paper gives an overview of the results from MINOS, and of the sensitivity of the NOνA experiment.
Statistical inference for association studies using electronic health records: handling both selection bias and outcome misclassification

Health research using electronic health records (EHR) has gained popularity, but misclassification of EHR-derived disease status and lack of representativeness of the study sample can result in substantial bias in effect estimates and can impact power and type I error. In this paper, we develop new strategies for handling disease status misclassification and selection bias in EHR-based association studies. We first focus on each type of bias separately. For misclassification, we propose three novel likelihood-based bias correction strategies. A distinguishing feature of the EHR setting is that misclassification may be related to patient-varying factors, and the proposed methods leverage data in the EHR to estimate misclassification rates without gold standard labels. For addressing selection bias, we describe how calibration and inverse probability weighting methods from the survey sampling literature can be extended and applied to the EHR setting. Addressing misclassification and selection biases simultaneously is a more challenging problem than dealing with each on its own, and we propose several new strategies. For all methods proposed, we derive valid standard error estimators and provide software for implementation. We provide a new suite of statistical estimation and inference strategies for addressing misclassification and selection bias simultaneously that is tailored to problems arising in EHR data analysis. We apply these methods to data from The Michigan Genomics Initiative, a longitudinal EHR-linked biorepository.
Planck Lensing and Cosmic Infrared Background Cross-Correlation with Fermi-LAT: Tracing Dark Matter Signals in the Gamma-Ray Background

The extragalactic $\gamma$-ray background and its spatial anisotropy could potentially contain a signature of dark matter (DM) annihilation or particle decay. Astrophysical foregrounds, such as blazars and star-forming galaxies (SFGs), however, dominate the $\gamma$-ray background, precluding an easy detection of the signal associated with the DM annihilation or decay in the background intensity spectrum. The DM imprint on the $\gamma$-ray background is expected to be correlated with large-scale structure tracers. In some cases, such a cross-correlation is even expected to have a higher signal-to-noise ratio than the auto-correlation. One reliable tracer of the DM distribution in the large-scale structure is lensing of the cosmic microwave background (CMB), and the cosmic infrared background (CIB) is a reliable tracer of SFGs. We analyze Fermi-LAT data taken over 92 months and study the cross-correlation with Planck CMB lensing, Planck CIB, and Fermi-$\gamma$ maps. We put upper limits on the DM annihilation cross-section from the cross-power spectra with the $\gamma$-ray background anisotropies. The unbiased power spectrum estimation is validated with simulations that include cross-correlated signals. We also provide a set of systematic tests and show that no significant contaminations are found for the measurements presented here. Using $\gamma$-ray background map from data gathered over 92 months, we find the best constraint on the DM annihilation with a $1\sigma$ confidence level upper limit of $10^{-25}$-$10^{-24}$ cm$^{3}$ s$^{-1}$, when the mass of DM particles is between 20 and 100 GeV.
Expected resurgences and symbolic powers of ideals

We give explicit criteria that imply the resurgence of a self-radical ideal in a regular ring is strictly smaller than its codimension, which in turn implies that the stable version of Harbourne's conjecture holds for such ideals. This criterion is used to give several explicit families of such ideals, including the defining ideals of space monomial curves. Other results generalize known theorems concerning when the third symbolic power is in the square of an ideal, and a strong resurgence bound for some classes of space monomial curves.
Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis

We derived a new method for direct calculation of the modal contributions to thermal conductivity, which is termed Green–Kubo modal analysis (GKMA). The GKMA method combines the lattice dynamics formalism with the Green–Kubo formula for thermal conductivity, such that the thermal conductivity becomes a direct summation of modal contributions, where one need not define the phonon velocity. As a result, the GKMA method can be applied to any material/group of atoms, where the atoms vibrate around stable equilibrium positions, which includes non-stoichiometric compounds, random alloys, amorphous materials and even rigid molecules. By using molecular dynamics simulations to obtain the time history of each mode's contribution to the heat current, one naturally includes anharmonicity to full order and can obtain insight into the interactions between different modes through the cross-correlations. As an example, we applied the GMKA method to crystalline and amorphous silicon. The modal contributions at each frequency result from the analysis and thereby allow one to apply a quantum correction to the mode heat capacity to determine the temperature dependence of thermal conductivity. The predicted temperature dependent thermal conductivity for amorphous silicon shows the best agreement with experiments to date. The GKMA method provides new insight into the nature of phonon transport, as it casts the problem in terms of mode–mode correlation instead of scattering, and provides a general unified formalism that can be used to understand phonon–phonon interactions in essentially any class of materials or structures where the atoms vibrate around stable equilibrium sites.
Entanglement spectroscopy with a depth-two quantum circuit

Noisy intermediate-scale quantum (NISQ) computers have gate errors and decoherence, limiting the depth of circuits that can be implemented on them. A strategy for NISQ algorithms is to reduce the circuit depth at the expense of increasing the qubit count. Here, we exploit this trade-off for an application called entanglement spectroscopy, where one computes the entanglement of a state $| \psi \rangle$ on systems $AB$ by evaluating the Renyi entropy of the reduced state $\rho_A = {\rm Tr}_B(| \psi \rangle \langle \psi |)$. For a $k$-qubit state $\rho(k)$, the Renyi entropy of order $n$ is computed via ${\rm Tr}(\rho(k)^{n})$, with the complexity growing exponentially in $k$ for classical computers. Johri, Steiger, and Troyer [PRB 96, 195136 (2017)] introduced a quantum algorithm that requires $n$ copies of $| \psi \rangle$ and whose depth scales linearly in $k*n$. Here, we present a quantum algorithm requiring twice the qubit resources ($2n$ copies of $| \psi \rangle$) but with a depth that is independent of both $k$ and $n$. Surprisingly this depth is only two gates. Our numerical simulations show that this short depth leads to an increased robustness to noise.
Aspherical Products Which do not Support Anosov Diffeomorphisms

We show that the product of infranilmanifolds with certain aspherical closed manifolds do not support Anosov diffeomorphisms. As a special case, we obtain that products of a nilmanifold and negatively curved manifolds of dimension at least 3 do not support Anosov diffeomorphisms.
Quasiparticle scattering interference in (K,Tl)FexSe2 superconductors

We model the quasiparticle interference (QPI) pattern in the recently discovered (K,Tl)FexSe2 superconductors. We show in the superconducting state that, due to the absence of hole pockets at the Brillouin zone center, the quasiparticle scattering occurs around the momentum transfer q = (0,0) and (±π,±π) between electron pockets located at the zone boundary. More importantly, although both dx2−y2-wave and s-wave pairing symmetry lead to nodeless quasiparticle excitations, distinct QPI features are predicted between both types of pairing symmetry. The so-called Z-map of the QPI exhibits strongest scattering with q = (±π,±π) for the dx2−y2-wave pairing symmetry, which is absent in the case of an isotropic s-wave pairing symmetry. The significant contrast in the QPI pattern between the dx2−y2-wave and the isotropic s-wave pairing symmetry can be used to probe the pairing symmetry within the Fourier-transform STM technique.
An Axiomatic Approach to Liveness for Differential Equations

This paper presents an approach for deductive liveness verification for ordinary differential equations (ODEs) with differential dynamic logic. Numerous subtleties complicate the generalization of well-known discrete liveness verification techniques, such as loop variants, to the continuous setting. For example, ODE solutions may blow up in finite time or their progress towards the goal may converge to zero. Our approach handles these subtleties by successively refining ODE liveness properties using ODE invariance properties which have a well-understood deductive proof theory. This approach is widely applicable: we survey several liveness arguments in the literature and derive them all as special instances of our axiomatic refinement approach. We also correct several soundness errors in the surveyed arguments, which further highlights the subtlety of ODE liveness reasoning and the utility of our deductive approach. The library of common refinement steps identified through our approach enables both the sound development and justification of new ODE liveness proof rules from our axioms.
Holographic duals of inhomogeneous systems: The rainbow chain and the sine-square deformation model

A holographic dual description of inhomogeneous systems is discussed. Notably, finite temperature results for the entanglement entropy in both the rainbow chain and the SSD model are obtained holographically by choosing appropriate foliations of the BTZ spacetime. Other inhomogeneous theories are also discussed. The entanglement entropy results are verified numerically, indicating that a wide variety of inhomogeneous field theory phenomenology can be seen in different slicings of asymptotically $AdS_3$ spacetimes.
Parallel clustering of high-dimensional social media data streams

We introduce Cloud DIKW (Data, Information, Knowledge, Wisdom) as an analysis environment supporting scientific discovery through integrated parallel batch and streaming processing, and apply it to one representative domain application: social media data stream clustering. In this context, recent work demonstrated that high-quality clusters can be generated by representing the data points using high-dimensional vectors that reflect textual content and social network information. However, due to the high cost of similarity computation, sequential implementations of even single-pass algorithms cannot keep up with the speed of real-world streams. This paper presents our efforts in meeting the constraints of real-time social media stream clustering through parallelization in Cloud DIKW. Specifically, we focus on two system-level issues. Firstly, most stream processing engines such as Apache Storm organize distributed workers in the form of a directed acyclic graph (DAG), which makes it difficult to dynamically synchronize the state of parallel clustering workers. We tackle this challenge by creating a separate synchronization channel using a pub-sub messaging system (ActiveMQ in our case). Secondly, due to the sparsity of the high-dimensional vectors, the size of centroids grows quickly as new data points are assigned to the clusters. As a result, traditional synchronization that directly broadcasts cluster centroids becomes too expensive and limits the scalability of the parallel algorithm. We address this problem by communicating only dynamic changes of the clusters rather than the whole centroid vectors. Our algorithm under Cloud DIKW can process the Twitter 10% data stream ("gardenhose") in real-time with 96-way parallelism. By natural improvements to Cloud DIKW, including advanced collective communication techniques developed in our Harp project, we will be able to process the full Twitter data stream in real-time with 1000-way parallelism. Our use of powerful general software subsystems will enable many other applications that need integration of streaming and batch data analytics.
Regular Versus Singular Order of Contact on Pseudoconvex Hypersurfaces

The singular and regular type of a point on a real hypersurface $${\mathcal H}$$ in $${\mathbb {C}}^n$$ are shown to agree when the regular type is strictly less than 4. If $${\mathcal H}$$ is pseudoconvex, we show they agree when the regular type is 4. A non-pseudoconvex example is given where the regular type is 4 and the singular type is infinite.
Poisson-Nernst-Planck Systems for Narrow Tubular-Like Membrane Channels

We study global asymptotic behavior of Poisson–Nernst–Planck (PNP) systems for flow of two ion species through a narrow tubular-like membrane channel. As the radius of the cross-section of the three-dimensional tubular-like membrane channel approaches zero, a one-dimensional limiting PNP system is derived. This one-dimensional limiting system differs from previously studied one-dimensional PNP systems in that it encodes the defining geometry of the three-dimensional membrane channel. To justify this limiting process, we show that the global attractors of the three-dimensional PNP systems are upper semi-continuous as the radius of the channel tends to zero.
ENTROPY OF OPERATOR-VALUED RANDOM VARIABLES: A VARIATIONAL PRINCIPLE FOR LARGE N MATRIX MODELS

We show that, in 't Hooft's large N limit, matrix models can be formulated as a classical theory whose equations of motion are the factorized Schwinger–Dyson equations. We discover an action principle for this classical theory. This action contains a universal term describing the entropy of the noncommutative probability distributions. We show that this entropy is a nontrivial one-cocycle of the noncommutative analog of the diffeomorphism group and derive an explicit formula for it. The action principle allows us to solve matrix models using novel variational approximation methods; in the simple cases where comparisons with other methods are possible, we get reasonable agreement.
Enhanced UV light detection using wavelength-shifting properties of Silicon nanoparticles

Detection of UV photons is becoming increasingly necessary with the use of noble gases and liquids in elementary particle experiments. Cerenkov light in crystals and glasses, scintillation light in neutrino, dark matter, and rare decay experiments all require sensitivity to UV photons. New sensor materials are needed that can directly detect UV photons and/or absorb UV photons and re-emit light in the visible range measurable by existing photosensors. It has been shown that silicon nanoparticles are sensitive to UV light in a wavelength range around ~ 200 nm. UV light is absorbed and re-emitted at wavelengths in the visible range depending on the size of the nanoparticles. Initial tests of the wavelength-shifting properties of silicon nanoparticles are presented here that indicate by placing a film of nanoparticles in front of a standard visible-wavelength detecting photosensor, the response of the sensor is significantly enhanced at wavelengths < 320 nm.
A non-abelian analogue of DBI from $T \overline{T}$

The Dirac action describes the physics of the Nambu-Goldstone scalars found on branes. The Born-Infeld action defines a non-linear theory of electrodynamics. The combined Dirac-Born-Infeld (DBI) action describes the leading interactions supported on a single D-brane in string theory. We define a non-abelian analogue of DBI using the $T \overline{T}$ deformation in two dimensions. The resulting quantum theory is compatible with maximal supersymmetry and such theories are quite rare.
Greedy Maximal Scheduling in Wireless Networks

In this paper we consider greedy scheduling algorithms in wireless networks, i.e., the schedules are computed by adding links greedily based on some priority vector. Two special cases are considered: 1) Longest Queue First (LQF) scheduling, where the priorities are computed using queue lengths, and 2) Static Priority (SP) scheduling, where the priorities are pre-assigned. We first propose a closed-form lower bound stability region for LQF scheduling, and discuss the tightness result in some scenarios. We then propose an lower bound stability region for SP scheduling with multiple priority vectors, as well as a heuristic priority assignment algorithm, which is related to the well-known Expectation Maximization (EM) algorithm. The performance gain of the proposed heuristic algorithm is finally confirmed by simulations.
CONNECTING DARK MATTER HALOS WITH THE GALAXY CENTER AND THE SUPERMASSIVE BLACK HOLE

Observational studies of nearby galaxies have demonstrated correlations between the mass of the central supermassive black holes (BHs) and properties of the host galaxies, notably the stellar bulge mass or central stellar velocity dispersion. Motivated by these correlations, the theoretical paradigm has emerged in which BHs and bulges coevolve. However, this picture was challenged by observational and theoretical studies, which hinted that the fundamental connection may be between BHs and dark matter halos, and not necessarily with their host galaxies. Based on a study of 3130 elliptical galaxies selected from the Sloan Digital and ROSAT All Sky Surveys we demonstrate that the central stellar velocity dispersion exhibits a significantly tighter correlation with the total gravitating mass, traced by the X-ray luminosity of the hot gas, than with the stellar mass. This hints that the central stellar velocity dispersion, and hence the central gravitational potential, may be the fundamental property of elliptical galaxies that is most tightly connected to the larger-scale dark matter halo. Furthermore, using the central stellar velocity dispersion as a surrogate for the BH mass, we find that in elliptical galaxies the inferred BH mass and inferred total gravitating mass within the virial radius (or within five effective radii) can be expressed as (or ). These results are consistent with a picture in which the BH mass is directly set by the central stellar velocity dispersion, which, in turn, is determined by the total gravitating mass of the system.
THE EVOLVING PHOTOMETRIC LIGHTCURVE OF COMET 1P/HALLEY’S COMA DURING THE 1985/86 APPARITION

We present new analyses of the photometric lightcurve of Comet 1P/Halley during its 1985/86 apparition. As part of a worldwide campaign coordinated by the International Halley Watch (IHW), narrowband photometry using standardized filters was obtained with telescopes at 18 observatories. Following submissions to and basic reductions by the Photometry and Polarimetry Network of the IHW, we further reduced the resulting fluxes to production rates and, following temporal binning, created composite lightcurves for each species. These were used to measure how the apparent rotational period (~7.35 days), along with its shape, evolved with time during the apparition. The lightcurve shape systematically varied from double-peaked to triple-peaked and back again every 8–9 weeks, due to Halley's non-principal axis (complex) rotation and the associated component periods. Unexpectedly, we found that a phase shift of one-half cycle also took place during this interval, and therefore the actual beat frequency between the component periods is twice this interval or 16–18 weeks. Preliminary modeling suggests that a single source might produce the entire post-perihelion lightcurve variability and associated evolution, and an additional source is probably also required to explain additional features before perihelion. The detailed evolution of the apparent period varied in a nonsmooth manner between 7.2 and 7.6 days, likely due to a combination of synodic effects and the interaction of solar illumination with isolated source regions on a body in complex rotation. The need to simultaneously reproduce each of these characteristics will provide very strong additional constraints on Halley's component periods associated with its complex rotation. To assist in these and future analyses, we created a synthetic lightcurve based directly on the measured data and how the lightcurve shape evolved week to week. This synthetic lightcurve was successfully compared to other data sets of Halley and provides a valuable estimate of Halley's activity even when no narrowband photometry measurements were obtained. We unexpectedly discovered a strong correlation of start times of ion tail disconnection events with minima in the comet's gas production, implying that a decrease in outgassing is another cause of these events.
Toward an Automated HPC Pipeline for Processing Large Scale Electron Microscopy Data

We present a fully modular and scalable software pipeline for processing electron microscope (EM) images of brain slices into 3D visualization of individual neurons and demonstrate an end-to-end segmentation of a large EM volume using a supercomputer. Our pipeline scales multiple packages used by the EM community with minimal changes to the original source codes. We tested each step of the pipeline individually, on a workstation, a cluster, and a supercomputer. Furthermore, we can compose workflows from these operations using a Balsam database that can be triggered during the data acquisition or with the use of different front ends and control the granularity of the pipeline execution. We describe the implementation of our pipeline and modifications required to integrate and scale up existing codes. The modular nature of our environment enables diverse research groups to contribute to the pipeline without disrupting the workflow, i.e. new individual codes can be easily integrated for each step on the pipeline.
Initiation stage of nanosecond breakdown in liquid

In this paper, based on a theoretical model (Shneider and Pekker 2013 Phys. Rev. E 87 043004), it has been shown experimentally that the initial stage of development of a nanosecond breakdown in liquids is associated with the appearance of discontinuities in the liquid (cavitation) under the influence of electrostriction forces. Comparison of experimentally measured area dimensions and its temporal development were found to be in a good agreement with the theoretical calculations. This work is a continuation of the experimental and theoretical works (Dobrynin et al 2013 J. Phys. D: Appl. Phys. 46 105201, Starikovskiy 2013 Plasma Sources Sci. Technol. 22 012001, Seepersad et al 2013 J. Phys. D: Appl. Phys. 46 162001, Marinov et al 2013 Plasma Sources Sci. Technol. 22 042001, Seepersad et al 2013 J. Phys. D: Appl. Phys. 46 3555201), initiated by the work in (Shneider et al 2012 IEEE Trans. Dielectr. Electr. Insul. 19 1597–82), in which the electrostriction mechanism of breakdown was proposed.