cssi/SciSciGPT-SciSciNet huggingface dataset:
100% reliable algorithm for second-harmonic-generation frequency-resolved optical gating.

We demonstrate a novel algorithmic approach for the second-harmonic-generation (SHG) frequency-resolved optical gating (FROG) ultrashort-pulse-measurement technique that always converges and, for complex pulses, is also much faster. It takes advantage of the Paley-Wiener Theorem to retrieve the precise pulse spectrum—half the desired information—directly from the measured trace. It also uses a multi-grid approach, permitting the algorithm to operate on smaller arrays for early iterations and on the complete array for only the final few iterations. We tested this approach on more than 25,000 randomly generated complex pulses with time-bandwidth products up to 100, yielding SHG FROG traces to which noise was added, and have achieved convergence to the correct pulse in all cases. Moreover, convergence occurs in less than half the time for extremely large traces corresponding to extremely complex pulses.
Planar master integrals for four-loop form factors

We present the complete set of planar master integrals relevant to the calculation of three-point functions in four-loop massless Quantum Chromodynamics. Employing direct parametric integrations for a basis of finite integrals, we give analytic results for the Laurent expansion of conventional integrals in the parameter of dimensional regularization through to terms of weight eight.
A LATE-TIME FLATTENING OF LIGHT CURVES IN GAMMA-RAY BURST AFTERGLOWS

The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from relativistic electrons accelerated at the GRB external shock. We investigate the temporal decay of the afterglow emission at late times, when the bulk of the shock-accelerated electrons are non-relativistic (the 'deep Newtonian phase', as denoted by Huang and Cheng). We assume that the electron spectrum in the deep Newtonian phase is a power-law distribution in momentum with slope p, as dictated by the theory of Fermi acceleration in non-relativistic shocks. For a uniform circumburst medium, the deep Newtonian phase begins at t{sub DN}∼3 ϵ{sub e,−1}{sup 5/6}t{sub ST}, where t {sub ST} marks the transition of the blast wave to the non-relativistic, spherically symmetric Sedov-Taylor (ST) solution, and e {sub e} = 0.1 e {sub e,–1} quantifies the amount of shock energy transferred to the electrons. For typical parameters, the deep Newtonian stage starts ∼0.5 to several years after the GRB. The radio flux in this phase decays as F {sub ν}∝t {sup –3(p+1)/10}∝t {sup –(0.9÷1.2)}, for a power-law slope 2 < p < 3. This is shallower than the scaling F {sub ν}∝t {sup –3(5p–7)/10}∝t {sup –(0.9÷2.4)} derived by Frail et al., which only applies ifmore » the GRB shock is non-relativistic, but the electron distribution still peaks at ultra-relativistic energies (a regime that is relevant for a narrow time interval, and only if t {sub DN} ≳ t {sub ST}, namely, e {sub e} ≳ 0.03). We discuss how the deep Newtonian phase can be reliably used for GRB calorimetry, and we comment on the good detection prospects of trans-relativistic blast waves at 0.1÷10 GHz with the Karl G. Jansky Very Large Array and LOw-Frequency ARray.« less
Unravelling the contribution of local structures to the anomalies of water: The synergistic action of several factors.

We investigate the microscopic origin of water’s anomalies by inspecting the hydrogen bond network (HBN) and the spatial organization of low-density-liquid (LDL) like and high-density-liquid (HDL) like environments. Specifically, we simulate—via classical molecular dynamics simulations—the isobaric cooling of a sample composed of 512 water molecules from ambient to deeply undercooled conditions at three pressures, namely, 1 bar, 400 bars, and 1000 bars. In correspondence with the Widom line (WL), (i) the HDL-like dominating cluster undergoes fragmentation caused by the percolation of LDL-like aggregates following a spinodal-like kinetics; (ii) such fragmentation always occurs at a “critical” concentration of ∼20%–30% in LDL; (iii) the HBN within LDL-like environments is characterized by an equal number of pentagonal and hexagonal rings that create a state of maximal frustration between a configuration that promotes crystallization (hexagonal ring) and a configuration that hinders it (pentagonal ring); (iv) the spatial organization of HDL-like environments shows a marked variation. Moreover, the inspection of the global symmetry shows that the intermediate-range order decreases in correspondence with the WL and such a decrease becomes more pronounced upon increasing the pressure, hence supporting the hypothesis of a liquid-liquid critical point. Our results reveal and rationalize the complex microscopic origin of water’s anomalies as the cooperative effect of several factors acting synergistically. Beyond implications for water, our findings may be extended to other materials displaying anomalous behaviours.
WIYN Open Cluster Study. LXXI. Spectroscopic Membership and Orbits of NGC 6791 Sub-Subgiants

In an optical color-magnitude diagram sub-subgiants (SSGs) lie red of the main sequence and fainter than the base of the red giant branch in a region not easily populated by standard stellar-evolution pathways. In this paper, we present multi-epoch radial velocities for five SSG candidates in the old and metal-rich open cluster NGC 6791 (8 Gyr, [Fe/H] = +0.30). From these data we are able to make three-dimensional kinematic membership determinations and confirm four SSG candidates to be likely cluster members. We also identify three member SSGs as short-period binary systems and present their orbital solutions. These are the first SSGs with known three-dimensional kinematic membership, binary status, and orbital parameters since the two SSGs in M67 studied by Mathieu et al. 2003. We also remark on the other properties of these stars including photometric variability, H$\alpha$ emission, and X-ray luminosity. The membership confirmation of these SSGs in NGC 6791 strengthens the case that SSGs are a new class of nonstandard stellar evolution products, and that a physical mechanism must be found that explains the evolutionary paths of these stars.
Mechanisms of Size Control and Polymorphism in Viral Capsid Assembly

We simulate the assembly dynamics of icosahedral capsids from subunits that interconvert between different conformations (or quasi-equivalent states). The simulations identify mechanisms by which subunits form empty capsids with only one morphology but adaptively assemble into different icosahedral morphologies around nanoparticle cargoes with varying sizes, as seen in recent experiments with brome mosaic virus (BMV) capsid proteins. Adaptive cargo encapsidation requires moderate cargo−subunit interaction strengths; stronger interactions frustrate assembly by stabilizing intermediates with incommensurate curvature. We compare simulation results to experiments with cowpea chlorotic mottle virus empty capsids and BMV capsids assembled on functionalized nanoparticles and suggest new cargo encapsidation experiments. Finally, we find that both empty and templated capsids maintain the precise spatial ordering of subunit conformations seen in the crystal structure even if interactions that preserve this arrangem...
A Continuous Teleoperation Subspace with Empirical and Algorithmic Mapping Algorithms for Non-Anthropomorphic Hands.

Teleoperation is a valuable tool for robotic manipulators in highly unstructured environments. However, finding an intuitive mapping between a human hand and a nonanthropomorphic robot hand can be difficult, due to the hands' dissimilar kinematics. In this article, we seek to create a mapping between the human hand and a fully actuated, nonanthropomorphic robot hand that is intuitive enough to enable effective real-time teleoperation, even for novice users. To accomplish this, we propose a low-dimensional teleoperation subspace that can be used as an intermediary for mapping between hand pose spaces. We present two different methods to define the teleoperation subspace: an empirical definition, which requires a person to define hand motions in an intuitive, hand-specific way, and an algorithmic definition, which is kinematically independent and uses objects to define the subspace. We use each of these definitions to create a teleoperation mapping for different hands.
Twisted logarithmic modules of free field algebras

Given a non-semisimple automorphism φ of a vertex algebra V, the fields in a φ-twisted V-module involve the logarithm of the formal variable, and the action of the Virasoro operator L0 on such a module is not semisimple. We construct examples of such modules and realize them explicitly as Fock spaces when V is generated by free fields. Specifically, we consider the cases of symplectic fermions (odd superbosons), free fermions, and βγ-system (even superfermions). In each case, we determine the action of the Virasoro algebra.
The Dependence of the Galaxy Luminosity Function on Environment

We present luminosity functions for galaxies in loose groups in the Las Campanas Redshift Survey, differentiated by their environment (defined by the line-of-sight velocity dispersion σ of the host groups) and also by their spectral type (emission or nonemission, defined by the equivalent width of the [O II] λ3727 line). We find systematic variations in the Schechter parameters α and M* for non-emission-line galaxies over a range of 0 < σ < 800 km s-1: α varies from 0.20 to -0.91, indicating an increase in the steepness of the faint end slope with increasing σ. The accompanying variation in M* appears to be accounted for by the intrinsic correlation with α and does not indicate a significant physical variation in the bright end of the luminosity function. For emission-line galaxies, we find no significant systematic variation of the luminosity function with the environment. Our results show that emission and nonemission galaxies generally occupy two distinct regions in the α-M* parameter space. From our luminosity functions, we derive the number ratios of emission to nonemission galaxies as a function of environment and absolute magnitude, showing that the relative abundance of non-emission-line galaxies generally increases for all magnitudes -23 < MR < -17.5 toward high-σ environments, from ~80% to more than 90% at MR = -22 and from ~10% to more than 50% at MR = -18 (H0 = 100 km s-1 Mpc-1 and q0 = 0.5).
Tandem coding and cryptography on wiretap channels: EXIT chart analysis

Traditional cryptography assumes an eavesdropper receives an error-free copy of the transmitted ciphertext. Wyner's wiretap channel model recognizes that at the physical layer both the intended receiver and the passive eavesdropper inevitably receive an error-prone version of the transmitted message which must be corrected prior to decryption. This paper considers the implications of using both channel and cryptographic codes under the wiretap channel model in a way that enhances the information-theoretic security for the friendly parties by keeping the information transfer to the eavesdropper small. We consider a secret-key cryptographic system with a linear feedback shift register (LFSR)-based keystream generator and observe the mutual information between an LFSR-generated sequence and the received noise-corrupted ciphertext sequence under a known-plaintext scenario. The effectiveness of a noniterative fast correlation attack, which reduces the search time in a brute-force attack, is shown to be correlated with this mutual information. For an iterative fast correlation attack on this cryptographic system, it is shown that an EXIT chart and mutual information are very good predictors of decoding success and failure by a passive eavesdropper.
Theoretical analysis of a nearly optimal analog quantum search

We analyze the possibility of modifying the original Farhi–Gutmann Hamiltonian algorithm in order to speed up the procedure for producing a suitably distributed unknown normalized quantum mechanical state. Such a modification is feasible provided only a nearly optimal fidelity is sought. We propose to select the lower bounds of the nearly optimal fidelity values such that their deviations from unit fidelity are less than the minimum error probability characterizing the optimum ambiguous discrimination scheme between the two non-orthogonal quantum states yielding the chosen nearly optimal fidelity values. Departing from the working assumptions of perfect state overlap and uniform distribution of the target state on the unit sphere in N-dimensional complex Hilbert space, we determine that the modified algorithm can indeed outperform the original analog counterpart of a quantum search algorithm. This performance enhancement occurs in terms of speed for a convenient choice of both the ratio γ = E '/E between the energy eigenvalues E ' and E of the modified search Hamiltonian and the quantum mechanical overlap x between the source and the target states. Finally, we briefly discuss possible analytical improvements of our investigation together with its potential relevance in practical quantum engineering applications.
Ergodic Jacobi Matrices and Conformal Maps

We study structural properties of the Lyapunov exponent γ and the density of states k for ergodic (or just invariant) Jacobi matrices in a general framework. In this analysis, a central role is played by the function w = − γ + iπ k as a conformal map between certain domains. This idea goes back to Marchenko and Ostrovskii, who used this device in their analysis of the periodic problem.
Relative velocity of inertial particles in turbulent flows

We present a model for the relative velocity of inertial particles in turbulent flows that provides new physical insight into this problem. Our general formulation shows that the relative velocity has contributions from two terms, referred to as the ‘generalized acceleration’ and ‘generalized shear’, because they reduce to the well-known acceleration and shear terms in the Saffman–Turner limit. The generalized shear term represents particles' memory of the flow velocity difference along their trajectories and depends on the inertial particle pair dispersion backward in time. The importance of this backward dispersion in determining the particle relative velocity is emphasized. We find that our model with a two-phase separation behaviour, an early ballistic phase and a later tracer-like phase, as found by recent simulations for the forward (in time) dispersion of inertial particle pairs, gives good fits to the measured relative speeds from simulations at low Reynolds numbers. In the monodisperse case with identical particles, the generalized acceleration term vanishes and the relative velocity is determined by the generalized shear term. At large Reynolds numbers, our model gives a St1/2-dependence of the relative velocity on the Stokes number St in the inertial range for both the ballistic behaviour and the Richardson separation law. This leads to the same inertial-range scaling for the two-phase separation that well fits the simulation results. Our calculations for the bidisperse case show that, with the friction timescale of one particle fixed, the relative speed as a function of the other particle's friction time has a dip when the two timescales are similar. This indicates that similar-size particles tend to have stronger velocity correlation than different ones. We find that the primary contribution at the dip, i.e. for similar particles, is from the generalized shear term, while the generalized acceleration term is dominant for particles of very different sizes. Future numerical studies are motivated to check the accuracy of the assumptions made in our model and to investigate the backward-in-time dispersion of inertial particle pairs in turbulent flows.
Pseudo-rotations and holomorphic curves

We prove a variant of the Chance–McDuff conjecture for pseudo-rotations: under certain additional conditions, a closed symplectic manifold which admits a Hamiltonian pseudo-rotation must have deformed quantum product and, in particular, some non-zero Gromov–Witten invariants. The only assumptions on the manifold are that it is weakly monotone and that its minimal Chern number is at least two. The conditions on the pseudo-rotation are expressed in terms of the linearized flow at one of the fixed points and are hypothetically satisfied for most (but not all) pseudo-rotations.
Delay-rate tradeoff for ergodic interference alignment in the Gaussian case

In interference alignment, users sharing a wireless channel are each able to achieve data rates of up to half of the non-interfering channel capacity, no matter the number of users. In an ergodic setting, this is achieved by pairing complementary channel realizations in order to amplify signals and cancel interference. However, this scheme has the possibility for large delays in decoding message symbols. We show that delay can be mitigated by using outputs from potentially more than two channel realizations, although data rate may be reduced. We further demonstrate the tradeoff between rate and delay via a time-sharing strategy. Our analysis considers Gaussian channels; an extension to finite field channels is also possible.
Light-Curve Calculations of Supernovae from Fallback Gamma-Ray Bursts

The currently favored model for long-duration gamma-ray bursts (GRBs) invokes explosions from the collapse of a massive star down to a black hole, either directly or through fallback. Those GRBs forming via fallback will produce much less radioactive nickel, and hence it has been argued (without any real calculation) that these systems produce dim supernovae. These fallback black hole GRBs have recently been argued as possible progenitors of a newly discovered set of GRBs lacking any associated supernovae. Here we present the first ever radiation-hydrodynamics calculations of the light curves produced in the hypernova explosion by a delayed-fallback gamma-ray burst. We find that the bolometric light curve is dominated by shock-deposited energy, not the decay of radioactive elements. As such, observations of such bursts actually probe the density in the progenitor wind more than it does the production of radioactive nickel.
Inverse Scattering of Canonical Systems and Their Evolution

In this work we present an analogue of the inverse scattering for canonical systems using theory of vessels and associated to them completely integrable systems. Analytic coefficients fits into this setting, significantly expanding the class of functions for which the inverse scattering exists. We also derive an evolutionary equation, arising from canonical systems, which describes an evolution of the logarithmic derivative of the tau function, associated to these systems.
Confirmation of WASP-107b’s Extended Helium Atmosphere with Keck II/NIRSPEC

We present the detection of helium in the extended atmosphere of the sub-Saturn WASP-107b using high resolution ($R \approx 25000$) near-infrared spectra from Keck II/NIRSPEC. We find peak excess absorption of $7.26 \pm 0.24\%$ (30$\sigma$) centered on the HeI triplet at 10833A. The amplitude and shape of the helium absorption profile is in excellent agreement with previous observations of escaping helium from this planet made by CARMENES and HST. This suggests there is no significant temporal variation in the signature of escaping helium from the planet over a two year baseline. This result demonstrates Keck II/NIRSPEC's ability to detect atmospheric escape in exoplanets, making it a useful instrument to further our understanding of the evaporation of exoplanetary atmospheres via ground-based observations of HeI.
On the Efetov–Wegner terms by diagonalizing a Hermitian supermatrix

The diagonalization of Hermitian supermatrices is studied. Such a change of coordinates is inevitable if one wishes to find certain structures in random matrix theory. However, it still poses serious problems since until now the calculation of all Rothstein contributions, known as Efetov–Wegner terms in physics, was quite cumbersome. We derive the supermatrix Bessel function with all Efetov–Wegner terms for an arbitrary rotation invariant probability density function. As applications we consider representations of generating functions for Hermitian random matrices with and without an external field as integrals over eigenvalues of Hermitian supermatrices. All results are obtained with all Efetov–Wegner terms which were previously unknown in such an explicit and compact representation.
Direct Dispersive Monitoring of Charge Parity in Offset-Charge-Sensitive Transmons

Improving the coherence of superconducting qubits is a crucial step toward the goal of fault-tolerant quantum processors based on them. An ongoing experimental challenge is to diagnose and mitigate the dominant decoherence mechanisms. In this work, the authors demonstrate a method of probing the decoherence induced by nonequilibrium superconducting quasiparticles, and show that improved filtering of quasiparticle-generating radiation can improve the energy-relaxation time ${T}_{1}$ of superconducting qubits, reaching an average of 200 $\ensuremath{\mu}$s in the measured device. Furthermore, the measurement technique is relevant for ultralow-noise sensing in general.
Predicting abandonment in online coding tutorials

Learners regularly abandon online coding tutorials when they get bored or frustrated, but there are few techniques for anticipating this abandonment to intervene. In this paper, we examine the feasibility of predicting abandonment with machine-learned classifiers. Using interaction logs from an online programming game, we extracted a collection of features that are potentially related to learner abandonment and engagement, then developed classifiers for each level. Across the first five levels of the game, our classifiers successfully predicted 61% to 76% of learners who did not complete the next level, achieving an average AUC of 0.68. In these classifiers, features negatively associated with abandonment included account activation and help-seeking behaviors, whereas features positively associated with abandonment included features indicating difficulty and dis-engagement. These findings highlight the feasibility of providing timely intervention to learners likely to quit.
COLLISIONLESS ISOTROPIZATION OF THE SOLAR-WIND PROTONS BY COMPRESSIVE FLUCTUATIONS AND PLASMA INSTABILITIES

Compressive fluctuations are a minor yet significant component of astrophysical plasma turbulence. In the solar wind, long-wavelength compressive slow-mode fluctuations lead to changes in ${\beta }_{\parallel {\rm{p}}}\equiv 8\pi {n}_{{\rm{p}}}{k}_{{\rm{B}}}{T}_{\parallel {\rm{p}}}/{B}^{2}$ and in ${R}_{{\rm{p}}}\equiv {T}_{\perp {\rm{p}}}/{T}_{\parallel {\rm{p}}}$, where ${T}_{\perp {\rm{p}}}$ and ${T}_{\parallel {\rm{p}}}$ are the perpendicular and parallel temperatures of the protons, B is the magnetic field strength, and ${n}_{{\rm{p}}}$ is the proton density. If the amplitude of the compressive fluctuations is large enough, ${R}_{{\rm{p}}}$ crosses one or more instability thresholds for anisotropy-driven microinstabilities. The enhanced field fluctuations from these microinstabilities scatter the protons so as to reduce the anisotropy of the pressure tensor. We propose that this scattering drives the average value of ${R}_{{\rm{p}}}$ away from the marginal stability boundary until the fluctuating value of ${R}_{{\rm{p}}}$ stops crossing the boundary. We model this "fluctuating-anisotropy effect" using linear Vlasov–Maxwell theory to describe the large-scale compressive fluctuations. We argue that this effect can explain why, in the nearly collisionless solar wind, the average value of ${R}_{{\rm{p}}}$ is close to unity.
Automated Identification of Hookahs (Waterpipes) on Instagram: An Application in Feature Extraction Using Convolutional Neural Network and Support Vector Machine Classification.

Background: Instagram, with millions of posts per day, can be used to inform public health surveillance targets and policies. However, current research relying on image-based data often relies on hand coding of images, which is time-consuming and costly, ultimately limiting the scope of the study. Current best practices in automated image classification (eg, support vector machine (SVM), backpropagation neural network, and artificial neural network) are limited in their capacity to accurately distinguish between objects within images. Objective: This study aimed to demonstrate how a convolutional neural network (CNN) can be used to extract unique features within an image and how SVM can then be used to classify the image. Methods: Images of waterpipes or hookah (an emerging tobacco product possessing similar harms to that of cigarettes) were collected from Instagram and used in the analyses (N=840). A CNN was used to extract unique features from images identified to contain waterpipes. An SVM classifier was built to distinguish between images with and without waterpipes. Methods for image classification were then compared to show how a CNN+SVM classifier could improve accuracy. Results: As the number of validated training images increased, the total number of extracted features increased. In addition, as the number of features learned by the SVM classifier increased, the average level of accuracy increased. Overall, 99.5% (418/420) of images classified were correctly identified as either hookah or nonhookah images. This level of accuracy was an improvement over earlier methods that used SVM, CNN, or bag-of-features alone. Conclusions: A CNN extracts more features of images, allowing an SVM classifier to be better informed, resulting in higher accuracy compared with methods that extract fewer features. Future research can use this method to grow the scope of image-based studies. The methods presented here might help detect increases in the popularity of certain tobacco products over time on social media. By taking images of waterpipes from Instagram, we place our methods in a context that can be utilized to inform health researchers analyzing social media to understand user experience with emerging tobacco products and inform public health surveillance targets and policies.
Josephson Junction Field-Effect Transistors for Boolean Logic Cryogenic Applications

Josephson junction FETs (JJ-FETs) share design similarities with MOSFETs, except for the source/drain contacts being replaced by superconductors. Similarly, the super current due to proximity effect is tunable by the gate voltage. In light of recent advances in novel materials and fabrication techniques, we examine here the feasibility of JJ-FET-based Boolean logic and memory elements for cryogenic computing. Using a 2-D ballistic transport JJ-FET model, we implement circuit-level simulations for JJ-FET logic gates and discuss criteria for realizing signal restoration, as well as fan-out. We show that the JJ-FET is a promising candidate for very low-power, clocked voltage-level dynamic logic at cryogenic temperatures.
Visualizing the logistic map with a microcontroller

The logistic map is one of the simplest nonlinear dynamical systems that clearly exhibits the route to chaos. In this paper, we explore the evolution of the logistic map using an open-source microcontroller connected to an array of light-emitting diodes (LEDs). We divide the one-dimensional domain interval [0,1] into ten equal parts, an associate and LED to each segment. Every time an iteration takes place a corresponding LED turns on, indicating the value returned by the logistic map. By changing some initial conditions of the system, it is easy to observe the transition from order to chaos exhibited by this map.
EXTERNAL PHOTOEVAPORATION OF THE SOLAR NEBULA. II. EFFECTS ON DISK STRUCTURE AND EVOLUTION WITH NON-UNIFORM TURBULENT VISCOSITY DUE TO THE MAGNETOROTATIONAL INSTABILITY

The structure and evolution of protoplanetary disks, especially the radial flows of gas through them, are sensitive to a number of factors. One that has been considered only occasionally in the literature is external photoevaporation by far-ultraviolet (FUV) radiation from nearby, massive stars, despite the fact that nearly half of all disks will experience photoevaporation. Another effect apparently not considered in the literature is a spatially and temporally varying value of $\alpha$ in the disk [where the turbulent viscosity $\nu$ is $\alpha$ times the sound speed C times the disk scale height H]. Here we use the formulation of Bai \& Stone (2011) to relate $\alpha$ to the ionization fraction in the disk, assuming turbulent transport of angular momentum is due to the magnetorotational instability. We find that disk evolution is most sensitive to the surface area of dust. Typically $\alpha \lesssim 10^{-5}$ in the inner disk ($ $\approx$ 2 - 5 in the 5-30 AU region) that is made steeper by external photoevaporation. We also find that the combination of variable $\alpha$ and external photoevaporation eventually causes gas as close as 3 AU, previously accreting inward, to be drawn outward to the photoevaporated outer edge of the disk. These effects have drastic consequences for planet formation and volatile transport in protoplanetary disks.
Analytical Expressions for Spiral Arm Gravitational Potential and Density

When modeling the three-dimensional hydrodynamics of interstellar material rotating in a galactic gravitational potential, it is useful to have an analytic expression for gravitational perturbations due to stellar spiral arms. We present such an expression for which changes in the assumed characteristics of the arms can be made easily and the sensitivity of the hydrodynamics to those characteristics examined. This analytic expression also makes it easy to rotate the force field at the pattern angular velocity with little overhead on the calculations.
Efficient Characterization of Hidden Processor Memory Hierarchies

A processor’s memory hierarchy has a major impact on the performance of running code. However, computing platforms, where the actual hardware characteristics are hidden from both the end user and the tools that mediate execution, such as a compiler, a JIT and a runtime system, are used more and more, for example, performing large scale computation in cloud and cluster. Even worse, in such environments, a single computation may use a collection of processors with dissimilar characteristics. Ignorance of the performance-critical parameters of the underlying system makes it difficult to improve performance by optimizing the code or adjusting runtime-system behaviors; it also makes application performance harder to understand.
Emerging Device Applications for Semiconducting Two-Dimensional Transition Metal Dichalcogenides

With advances in exfoliation and synthetic techniques, atomically thin films of semiconducting transition metal dichalcogenides have recently been isolated and characterized. Their two-dimensional structure, coupled with a direct band gap in the visible portion of the electromagnetic spectrum, suggests suitability for digital electronics and optoelectronics. Toward that end, several classes of high-performance devices have been reported along with significant progress in understanding their physical properties. Here, we present a review of the architecture, operating principles, and physics of electronic and optoelectronic devices based on ultrathin transition metal dichalcogenide semiconductors. By critically assessing and comparing the performance of these devices with competing technologies, the merits and shortcomings of this emerging class of electronic materials are identified, thereby providing a roadmap for future development.
A Cardy formula for holographic hyperscaling-violating theories

We propose a formalism for counting the microstates of a class of three- dimensional black holes which are not asymptotically AdS. The formalism rests on the invariance of a dual eld theory under a generalized modular transformation and is ex- tended to Rindler horizons by a singular limit. We also obtain logarithmic corrections.
Genetic sequence matching using D4M big data approaches

Recent technological advances in Next Generation Sequencing tools have led to increasing speeds of DNA sample collection, preparation, and sequencing. One instrument can produce over 600 Gb of genetic sequence data in a single run. This creates new opportunities to efficiently handle the increasing workload. We propose a new method of fast genetic sequence analysis using the Dynamic Distributed Dimensional Data Model (D4M) - an associative array environment for MATLAB developed at MIT Lincoln Laboratory. Based on mathematical and statistical properties, the method leverages big data techniques and the implementation of an Apache Acculumo database to accelerate computations one-hundred fold over other methods. Comparisons of the D4M method with the current gold-standard for sequence analysis, BLAST, show the two are comparable in the alignments they find. This paper will present an overview of the D4M genetic sequence algorithm and statistical comparisons with BLAST.
2004 TT357: A Potential Contact Binary in the Trans-Neptunian Belt

We report photometric observations of the trans-Neptunian object 2004 TT(sub 357) obtained in 2015 and 2017 using the 4.3 m Lowell's Discovery Channel Telescope. We derive a rotational period of 7.79 +/- 0.01 hr and a peak-to-peak lightcurve amplitude of 0.76 +/- 0.03 mag. 2004 TT(sub 357) displays a large variability that can be explained by a very elongated single object or can be due to a contact/close binary. The most likely scenario is that 2004 TT(sub 357) is a contact binary. If it is in hydrostatic equilibrium, we find that the lightcurve can be explained by a system with a mass ratio q(sub min) = 0.45 +/- 0.05, and a density of p(sub min) = 2 g/cu.cm, or less likely a system with q(sub max) = 0.8 +/- 0.05, and ρ(sub max) = 5 g/cu.cm. Considering a single triaxial ellipsoid in hydrostatic equilibrium, we derive a lower limit to the density of 0.78 g/cu.cm, and an elongation (a/b) of 2.01 assuming an equatorial view. From Hubble Space Telescope data, we report no resolved companion orbiting 2004 TT(sub 357). Despite an expected high fraction of contact binaries in the trans-Neptunian belt, 2001 QG(sub 298) is the unique confirmed contact binary in the trans- Neptunian belt, and 2004 TT(sub 357) is only the second candidate to this class of systems, with 2003 SQ(sub 317).
THE PARITY OF THE MASLOV INDEX AND THE EVEN COBORDISM CATEGORY

PATRICK M. GILMER AND KHALED QAZAQZEHAbstract. We give a formula for the parity of the Maslov index of a tripleof Lagrangian subspaces of a skew symmetric bilinear form over R. We deﬁnean index two subcategory (the even subcategory) of a 3-dimensional cobor-dism category. The objects of the category are surfaces are equipped withLagrangian subspaces of their real ﬁrst homology. This generalizes a resultof the ﬁrst author where surfaces are equipped with Lagrangian subspaces oftheir rational ﬁrst homology.
The Oxyometer: A Novel Instrument Concept for Characterizing Exoplanet Atmospheres

With TESS and ground-based surveys searching for rocky exoplanets around cooler, nearby stars, the number of Earth-sized exoplanets that are well-suited for atmospheric follow-up studies will increase significantly. For atmospheric characterization, the James Webb Space Telescope will only be able to target a small fraction of the most interesting systems, and the usefulness of ground-based observatories will remain limited by a range of effects related to Earth's atmosphere. Here, we explore a new method for ground-based exoplanet atmospheric characterization that relies on simultaneous, differential, ultra-narrow-band photometry. The instrument uses a narrow-band interference filter and an optical design that enables simultaneous observing over two 0.3 nm wide bands spaced 1 nm apart. We consider the capabilities of this instrument in the case where one band is centered on an oxygen-free continuum region while the other band overlaps the 760 nm oxygen band head in the transmission spectrum of the exoplanet, which can be accessible from Earth in systems with large negative line-of-sight velocities. We find that M9 and M4 dwarfs that meet this radial velocity requirement will be the easiest targets but must be nearby (<8 pc) and will require the largest upcoming Extremely Large Telescopes. The oxyometer instrument design is simple and versatile and could be adapted to enable the study of a wide range of atmospheric species. We demonstrate this by building a prototype oxyometer and present its design and a detection of a 50 ppm simulated transit signal in the laboratory. We also present data from an on-sky test of a prototype oxyometer, demonstrating the ease of use of the compact instrument design.
A 20-liter test stand with gas purification for liquid argon research

We describe the design of a 20-liter test stand constructed to study fundamental properties of liquid argon (LAr). This system utilizes a simple, cost-effective gas argon (GAr) purification to achieve high purity, which is necessary to study electron transport properties in LAr. An electron drift stack with up to 25 cm length is constructed to study electron drift, diffusion, and attachment at various electric fields. A gold photocathode and a pulsed laser are used as a bright electron source. The operational performance of this system is reported.
BLOOM'S INEQUALITY: COMMUTATORS IN A TWO-WEIGHT SETTING

In 1985, Bloom characterized the boundedness of the commutator [b, H] as a map between a pair of weighted L p spaces, where both weights are in A p . The characterization is in terms of a novel BMO condition. We give a ‘modern’ proof of this result, in the case of p = 2. In a subsequent paper, this argument will be used to generalize Bloom’s result to all Calderon–Zygmund operators and dimensions.
Excess in the High-frequency Radio Background: Insights from Planck

We conduct a stacking analysis using the combination of 1.4 GHz detections in the NRAO VLA Sky Survey (NVSS) and Planck all-sky maps to estimate the differential source counts down to the few 100 μJy level at 30, 44, 70, and 100 GHz. Using these source count estimates, we are able to measure the integrated extragalactic background light from discrete sources at these frequencies for comparison with the fit to the total radio sky measurements from ARCADE 2. By integrating down to a 1.4 GHz flux density of ≈2 μJy, we measure integrated, extragalactic brightness temperatures from discrete sources of 105.63 ± 10.56 mK, 21.76 ± 3.09 μK, 8.80 ± 0.95 μK, 2.59 ± 0.27 μK, and 1.15 ± 0.10 μk at 1.4, 30, 44, 70, and 100 GHz, respectively. Our measurement at 1.4 GHz is slightly larger than previous measurements, most likely due to using NVSS data compared with older interferometric data in the literature, but it still remains a factor of ≈4.5 below that required to account for the excess extragalactic sky brightness measured at 1.4 GHz by ARCADE 2. The fit to ARCADE 2 total extragalactic sky brightness measurements is also a factor of ≈8.6, 6.6, 6.2, and 4.9 times brighter than what we estimate from discrete sources at 30, 44, 70, and 100 GHz, respectively. The extragalactic sky spectrum (i.e., T_b ∝ ν^β ) from discrete sources appears to flatten with increasing frequency, having a spectral index of β = −2.82 ± 0.06 between 1.4 and 30 GHz, flattening to β = −2.39 ± 0.12 between 30 and 100 GHz. We estimate that the spectral flattening most likely arises from a combination of gigahertz-peaked sources and the hardening of the spectra of radio-detected sources at higher frequencies, particularly at faint flux densities. However, the precise origin of a hard component of energetic electrons responsible for the emission remains unclear.
Eccentric black-hole-neutron-star mergers

Within the next few years gravitational waves (GWs) from merging black holes (BHs) and neutron stars (NSs) may be directly detected, making a thorough theoretical understanding of these systems a high priority. As an additional motivation, these systems may represent a subset of short-duration gamma-ray burst progenitors. BH-NS mergers are expected to result from primordial, quasi-circular inspiral as well as dynamically formed capture binaries. The latter channel allows mergers with high eccentricity, resulting in a richer variety of outcomes. We perform general relativistic simulations of BH-NS interactions with a range of impact parameters, and find significant variation in the properties of these events that have potentially observable consequences, namely, the GW signature, remnant accretion disk mass, and amount of unbound material.
Classification with Valid and Adaptive Coverage

Conformal inference, cross-validation+, and the jackknife+ are hold-out methods that can be combined with virtually any machine learning algorithm to construct prediction sets with guaranteed marginal coverage. In this paper, we develop specialized versions of these techniques for categorical and unordered response labels that, in addition to providing marginal coverage, are also fully adaptive to complex data distributions, in the sense that they perform favorably in terms of approximate conditional coverage compared to alternative methods. The heart of our contribution is a novel conformity score, which we explicitly demonstrate to be powerful and intuitive for classification problems, but whose underlying principle is potentially far more general. Experiments on synthetic and real data demonstrate the practical value of our theoretical guarantees, as well as the statistical advantages of the proposed methods over the existing alternatives.
On an isoperimetric problem with a competing non-local term: quantitative results

This paper provides a quantitative version of the recent result of Knupfer and Muratov (Commun Pure Appl Math 66:1129–1162, 2013) concerning the solutions of an extension of the classical isoperimetric problem in which a non-local repulsive term involving Riesz potential is present. In that work, it was shown that in two space dimensions the minimizer of the considered problem is either a ball or does not exist, depending on whether or not the volume constraint lies in an explicit interval around zero, provided that the Riesz kernel decays sufficiently slowly. Here, we give an explicit estimate for the exponents of the Riesz kernel for which the result holds.
Magnetogenesis from axion inflation

In this work we compute the production of magnetic fields in models of axion inflation coupled to the hypercharge sector of the Standard Model through a Chern-Simons interaction term. We make the simplest choice of a quadratic inflationary potential and use lattice simulations to calculate the magnetic field strength, helicity and correlation length at the end of inflation. For small values of the axion-gauge field coupling strength the results agree with no-backreaction calculations and estimates found in the literature. For larger couplings the helicity of the magnetic field differs from the no-backreaction estimate and depends strongly on the comoving wavenumber. We estimate the post-inflationary evolution of the magnetic field based on known results for the evolution of helical and non-helical magnetic fields. The magnetic fields produced by axion inflation with large couplings to U(1)Y can reach Beff 10−16 G, exhibiting a field strength Bphys ≈ 10−13 G and a correlation length λphys ≈10 pc. This result is insensitive to the exact value of the coupling, as long as the coupling is large enough to allow for instantaneous preheating. Depending on the assumptions for the physical processes that determine blazar properties, these fields can be found consistent with blazar observations based on the value of Beff. Finally, the intensity of the magnetic field for large coupling can be enough to satisfy the requirements for a recently proposed baryogenesis mechanism, which utilizes the chiral anomaly of the Standard Model.
Systemic brain tumor delivery of synthetic protein nanoparticles for glioblastoma therapy

Glioblastoma (GBM), the most aggressive form of brain cancer, has witnessed very little clinical progress over the last decades, in part, due to the absence of effective drug delivery strategies. Intravenous injection is the least invasive drug delivery route to the brain, but has been severely limited by the blood-brain barrier (BBB). Inspired by the capacity of natural proteins and viral particulates to cross the BBB, we engineered a synthetic protein nanoparticle (SPNP) based on polymerized human serum albumin (HSA) equipped with the cell-penetrating peptide iRGD. SPNPs containing siRNA against Signal Transducer and Activation of Transcription 3 factor (STAT3i) result in in vitro and in vivo downregulation of STAT3, a central hub associated with GBM progression. When combined with the standard of care, ionized radiation, STAT3i SPNPs result in tumor regression and long-term survival in 87.5% of GBM-bearing mice and prime the immune system to develop anti-GBM immunological memory.
Rapid sequence identification of potential pathogens using techniques from sparse linear algebra

The decreasing costs and increasing speed and accuracy of DNA sample collection, preparation, and sequencing has rapidly produced an enormous volume of genetic data. However, fast and accurate analysis of the samples remains a bottleneck. Here we present D4RAGenS, a genetic sequence identification algorithm that exhibits the Big Data handling and computational power of the Dynamic Distributed Dimensional Data Model (D4M). The method leverages linear algebra and statistical properties to increase computational performance while retaining accuracy by subsampling the data. Two run modes, Fast and Wise, yield speed and precision tradeoffs, with applications in biodefense and medical diagnostics. The D4RAGenS analysis algorithm is tested over several datasets, including three utilized for the Defense Threat Reduction Agency (DTRA) metagenomic algorithm contest.
Randomness in nonlocal games between mistrustful players

If two quantum players at a nonlocal game G achieve a superclassical score, then their measurement outcomes must be at least partially random from the perspective of any third player. This is the basis for device-independent quantum cryptography. In this paper we address a related question: does a superclassical score at G guarantee that one player has created randomness from the perspective of the other player? We show that for complete-support games, the answer is yes: even if the second player is given the first player's input at the conclusion of the game, he cannot perfectly recover her output. Thus some amount of local randomness (i.e., randomness possessed by only one player) is always obtained when randomness is certified from nonlocal games with quantum strategies. This is in contrast to non-signaling game strategies, which may produce global randomness without any local randomness. We discuss potential implications for cryptographic protocols between mistrustful parties.
MEASUREMENT OF THE MASS AND STELLAR POPULATION DISTRIBUTION IN M82 WITH THE LBT

We present a K-band spectroscopic study of the stellar and gas kinematics, mass distribution, and stellar populations of the archetypical starburst galaxy M82. Our results are based on a single spectrum at a position angle of 67.{sup 0}5 through the K-band nucleus. We used the {sup 12}CO stellar absorption band head at 2.29 {mu}m (CO{sub 2.29}) to measure the rotation curve out to nearly 4 kpc radius on both the eastern and western sides of the galaxy. Our data show that the rotation curve is flat from 1 to 4 kpc. This stands in sharp contrast to some previous studies, which have interpreted H I and CO emission-line position-velocity diagrams as evidence for a declining rotation curve. The kinematics of the Br{gamma}, H{sub 2}, and He I emission lines are consistent with, although characterized by slightly higher velocities than, the stellar kinematics. We derived M82's mass distribution from our stellar kinematic measurements and estimate that its total dynamical mass is {approx}10{sup 10} M{sub Sun }. We measured the equivalent width of CO{sub 2.29} (W{sub 2.29}) as a function of distance from the center of the galaxy to investigate the spatial extent of the red supergiant (RSG) population. The variation inmore » W{sub 2.29} with radius clearly shows that RSGs dominate the light inside 500 pc radius. M82's superwind is likely launched from this region, where we estimate that the enclosed mass is {approx}<2 Multiplication-Sign 10{sup 9} M{sub Sun }.« less