cssi/SciSciGPT-SciSciNet huggingface dataset:
Flow-based algorithms for local graph clustering

Given a subset A of vertices of an undirected graph G, the cut-improvement problem asks us to find a subset S that is similar to A but has smaller conductance. An elegant algorithm for this problem has been given by Andersen and Lang [5] and requires solving a small number of single-commodity maximum flow computations over the whole graph G. In this paper, we introduce LocalImprove, the first cut-improvement algorithm that is local, i.e., that runs in time dependent on the size of the input set A rather than on the size of the entire graph. Moreover, LocalImprove achieves this local behavior while closely matching the same theoretical guarantee as the global algorithm of Andersen and Lang.The main application of LocalImprove is to the design of better local-graph-partitioning algorithms. All previously known local algorithms for graph partitioning are random-walk based and can only guarantee an output conductance of [EQUATION] when the target set has conductance φopt e [0, 1]. Very recently, Zhu, Lattanzi and Mirrokni [35] improved this to [EQUATION] where the internal connectivity parameter Conn e [0, 1] is defined as the reciprocal of the mixing time of the random walk over the graph induced by the target set. This regime is of high practical interest in learning applications as it corresponds to the case when the target set is a well-connected ground-truth cluster. In this work, we show how to use LocalImprove to obtain a constant approximation O(φopt) as long as Conn/φopt = Ω(1). This yields the first flow-based algorithm for local graph partitioning. Moreover, its performance strictly outperforms the ones based on random walks and surprisingly matches that of the best known global algorithm, which is SDP-based, in this parameter regime [25].Finally, our results show that spectral methods are not the only viable approach to the construction of local graph partitioning algorithm and open door to the study of algorithms with even better approximation and locality guarantees.
Distributions of historic market data – stock returns

We show that the moments of the distribution of historic stock returns are in excellent agreement with the Heston model and not with the multiplicative model, which predicts power-law tails of volatility and stock returns. We also show that the mean realized variance of returns is a linear function of the number of days over which the returns are calculated. The slope is determined by the mean value of the variance (squared volatility) in the mean-reverting stochastic volatility models, such as Heston and multiplicative, independent of stochasticity. The distribution function of stock returns, which rescales with the increase of the number of days of return, is obtained from the steady-state variance distribution function using the product distribution with the normal distribution.
On the definition and K-theory realization of a modular functor

We present a definition of a (super)-modular functor which includes certain interesting cases that previous definitions do not allow. We also introduce a notion of topological twisting of a modular functor, and construct formally a realization by a 2-dimensional topological field theory valued in twisted K-modules. We discuss, among other things, the N = 1-supersymmetric minimal models from the point of view of this formalism.
Fornax: A Flexible Code for Multiphysics Astrophysical Simulations

This paper describes the design and implementation of our new multi-group, multi-dimensional radiation hydrodynamics (RHD) code Fornax and provides a suite of code tests to validate its application in a wide range of physical regimes. Instead of focusing exclusively on tests of neutrino radiation hydrodynamics relevant to the core-collapse supernova problem for which Fornax is primarily intended, we present here classical and rigorous demonstrations of code performance relevant to a broad range of multi-dimensional hydrodynamic and multi-group radiation hydrodynamic problems. Our code solves the comoving-frame radiation moment equations using the M1 closure, utilizes conservative high-order reconstruction, employs semi-explicit matter and radiation transport via a high-order time stepping scheme, and is suitable for application to a wide range of astrophysical problems. To this end, we first describe the philosophy, algorithms, and methodologies of Fornax and then perform numerous stringent code tests, that collectively and vigorously exercise the code, demonstrate the excellent numerical fidelity with which it captures the many physical effects of radiation hydrodynamics, and show excellent strong scaling well above 100k MPI tasks.
Lie-algebraic curvature conditions preserved by the Hermitian curvature flow

The purpose of this paper is to prove that the Hermitian Curvature Flow (HCF) on an Hermitian manifold (M, g, J) preserves many natural curvature positivity conditions. Following ideas of Wilking (J Reine Angew Math 679:223–247, 2013), for an $$\text {Ad}\,{GL(T^{1,0}M)}$$ -invariant subset $$S\subset \text {End}\,(T^{1,0}M)$$ and a nice function $$F:\text {End}\,(T^{1,0}M)\rightarrow {\mathbb {R}}$$ we construct a convex set of curvature operators C(S, F), which is invariant under the HCF. Varying S and F, we prove that the HCF preserves Griffiths positivity, Dual-Nakano positivity, positivity of holomorphic orthogonal bisectional curvature, lower bounds on the second scalar curvature. As an application, we prove that stationary/periodic solutions to the HCF can exist only on manifolds M with the trivial canonical bundle on the universal cover $${\widetilde{M}}$$ .
Higgs and $Z$ Assisted Stop Searches at Hadron Colliders

Current searches for the light top squark (stop) mostly focus on the decay channels of $$ \tilde{t}\to t{\chi}_1^0 $$ or $$ \tilde{t}\to b{\chi}_1^{\pm}\to bW{\chi}_1^0 $$ , leading to final states for stop pair productions at the LHC. However, in supersymmetric scenarios with light neutralinos and charginos other than the neutralino lightest supersymmetric particle (LSP), more than one decay mode of the stop could be dominant. While those new decay modes could significantly weaken the current stop search limits at the LHC, they also offer alternative discovery channels for stop searches. In this paper, we studied the scenario with light Higgsino next-to-LSPs (NLSPs) and Bino LSP. The light stop decays primarily via $$ {\tilde{t}}_1\to t{\chi}_2^0/{\chi}_3^0 $$ , with the neutralinos subsequent decaying to a Z boson or a Higgs boson: χ 2 0 /χ 3 0 → χ 1 0 h/Z. Pair production of light stops at the LHC leads to final states of or . We consider three signal regions: one charged lepton (1l), two opposite sign charged leptons (2 OS l) and at least three charged leptons (≥3l). We found that the 1l signal region of channel has the best reach sensitivity for light stop searches. For 14 TeV LHC with 300 fb−1 integrated luminosity, a stop mass up to 900 GeV can be discovered at 5σ significance, or up to 1050 GeV can be excluded at 95% C.L. Combining all three decay channels for 1l signal region extends the reach for about 100−150 GeV. We also studied the stop reach at the 100 TeV pp collider with 3 ab−1 luminosity, with discovery and exclusion reach being 6 TeV and 7 TeV, respectively.
75,000,000,000 Streaming Inserts/Second Using Hierarchical Hypersparse GraphBLAS Matrices

The SuiteSparse GraphBLAS C-library implements high performance hypersparse matrices with bindings to a variety of languages (Python, Julia, and Matlab/Octave). GraphBLAS provides a lightweight in-memory database implementation of hypersparse matrices that are ideal for analyzing many types of network data, while providing rigorous mathematical guarantees, such as linearity. Streaming updates of hypersparse matrices put enormous pressure on the memory hierarchy. This work benchmarks an implementation of hierarchical hypersparse matrices that reduces memory pressure and dramatically increases the update rate into a hypersparse matrices. The parameters of hierarchical hypersparse matrices rely on controlling the number of entries in each level in the hierarchy before an update is cascaded. The parameters are easily tunable to achieve optimal performance for a variety of applications. Hierarchical hypersparse matrices achieve over 1,000,000 updates per second in a single instance. Scaling to 31,000 instances of hierarchical hypersparse matrices arrays on 1,100 server nodes on the MIT SuperCloud achieved a sustained update rate of 75,000,000,000 updates per second. This capability allows the MIT SuperCloud to analyze extremely large streaming network data sets.
THE INTERACTION OF TWO CORONAL MASS EJECTIONS: INFLUENCE OF RELATIVE ORIENTATION

We report on a numerical investigation of two coronal mass ejections (CMEs) that interact as they propagate in the inner heliosphere. We focus on the effect of the orientation of the CMEs relative to each other by performing four different simulations with the axis of the second CME rotated by 90° from one simulation to the next. Each magnetohydrodynamic simulation is performed in three dimensions with the Space Weather Modeling Framework in an idealized setting reminiscent of solar minimum conditions. We extract synthetic satellite measurements during and after the interaction and compare the different cases. We also analyze the kinematics of the two CMEs, including the evolution of their widths and aspect ratios. We find that the first CME contracts radially as a result of the interaction in all cases, but the amount of subsequent radial expansion depends on the relative orientation of the two CMEs. Reconnection between the two ejecta and between the ejecta and the interplanetary magnetic field determines the type of structure resulting from the interaction. When a CME with a high inclination with respect to the ecliptic overtakes one with a low inclination, it is possible to create a compound event with a smooth rotation inmore » the magnetic field vector over more than 180°. Due to reconnection, the second CME only appears as an extended 'tail', and the event may be mistaken for a glancing encounter with an isolated CME. This configuration differs significantly from the one usually studied of a multiple-magnetic-cloud event, which we found to be associated with the interaction of two CMEs with the same orientation.« less
Scattering for Radial, Semi-Linear, Super-Critical Wave Equations with Bounded Critical Norm

In this paper we study the focusing cubic wave equation in 1 + 5 dimensions with radial initial data as well as the one-equivariant wave maps equation in 1+3 dimensions with the model target manifolds \({\mathbb{S}^3}\) and \({\mathbb{H}^3}\). In both cases the scaling for the equation leaves the \({\dot{H}^{\frac{3}{2}} \times \dot{H}^{\frac{1}{2}}}\)-norm of the solution invariant, which means that the equation is super-critical with respect to the conserved energy. Here we prove a conditional scattering result: if the critical norm of the solution stays bounded on its maximal time of existence, then the solution is global in time and scatters to free waves as \({t \to \pm \infty}\). The methods in this paper also apply to all supercritical power-type nonlinearities for both the focusing and defocusing radial semi-linear equation in 1+5 dimensions, yielding analogous results.
The dynamics of the one-dimensional delta-function Bose gas

We give a method to solve the time-dependent Schroedinger equation for a system of one-dimensional bosons interacting via a repulsive delta function potential. The method uses the ideas of Bethe Ansatz but does not use the spectral theory of the associated Hamiltonian.
A euclidean lattice construction of supersymmetric Yang-Mills theories with sixteen supercharges

We formulate supersymmetric euclidean spacetime Ad* lattices whose classical continuum limits are U(N) supersymmetric Yang-Mills theories with sixteen supercharges in d = 1,2,3 and 4 dimensions. This family includes the especially interesting = 4 supersymmetry in four dimensions, as well as a euclidean path integral formulation of Matrix Theory on a one dimensional lattice.
THE FAR-ULTRAVIOLET SPECTRAL SIGNATURES OF FORMALDEHYDE AND CARBON DIOXIDE IN COMETS

Observations of four comets made with the Far-Ultraviolet Spectroscopic Explorer show the rotational envelope of the (0,0) band of the CO Hopfield-Birge system (C 1Σ+- X 1Σ+) at 1088 A to consist of both "cold" and "hot" components, the "cold" component accounting for ~75% of the flux and with a rotational temperature in the range 55 K-75 K. We identify the "hot" component as coming from the dissociation of CO2 into rotationally "hot" CO, with electron impact dissociation probably dominant over photodissociation near the nucleus. An additional weak, broad satellite band is seen centered near the position of the P(40) line that we attribute to CO fluorescence from a non-thermal high J rotational population produced by photodissociation of formaldehyde into CO and H2. This process also leaves the H2 preferentially populated in excited vibrational levels which are identified by fluorescent H2 lines in the spectrum excited by solar O VI λ1031.9 and solar Lyα. The amount of H2 produced by H2CO dissociation is comparable to the amount produced by photodissociation of H2O. Electron impact excitation of CO, rather than resonance fluorescence, appears to be the primary source of the observed B 1Σ+- X 1Σ+(0,0) band at 1151 A.
Brauer’s generalized decomposition numbers and universal deformation rings

The versal deformation ring R(G,V) of a mod p representation V of a profinite group G encodes all isomorphism classes of lifts of V to representations of G over complete local commutative Noetherian rings. We introduce a new technique for determining R(G,V) when G is finite which involves Brauer's generalized decomposition numbers.
Particle-to-fluid heat transfer in particle-laden turbulence

We analyze heat transfer between disperse and carrier phases in multiphase turbulent flows. We reduce the full characterization of the problem to two parameters: Stokes number based on large eddy time, and a dimensionless number indicating the ratio of gas thermal relaxation time to large eddy time.
First-Order Particle Acceleration in Magnetically-driven Flows

In this study, we demonstrate that particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. Some examples of such flows include spontaneous turbulent reconnection and decaying magnetohydrodynamic turbulence, where a magnetic field relaxes to a lower-energy configuration and transfers part of its energy to kinetic motions of the fluid. We show that this energy transfer, which normally causes turbulent cascade and heating of the fluid, also results in a first-order acceleration of non-thermal particles. Since it is generic, this acceleration mechanism is likely to play a role in the production of non-thermal particle distribution in magnetically dominant environments such as the solar chromosphere, pulsar magnetospheres, jets from supermassive black holes, and γ-ray bursts.
DC CIRCUIT POWERED BY ORBITAL MOTION: MAGNETIC INTERACTIONS IN COMPACT OBJECT BINARIES AND EXOPLANETARY SYSTEMS

The unipolar induction DC circuit model, originally developed by Goldreich and Lynden-Bell for the Jupiter-Io system, has been applied to different types of binary systems in recent years. We show that there exists an upper limit to the magnetic interaction torque and energy dissipation rate in such a model. This arises because when the resistance of the circuit is too small, the large current flow severely twists the magnetic flux tube connecting the two binary components, leading to the breakdown of the circuit. Applying this limit, we find that in coalescing neutron star binaries, magnetic interactions produce negligible correction to the phase evolution of the gravitational waveform, even for magnetar-like field strengths. However, energy dissipation in the binary magnetosphere may still give rise to electromagnetic radiation prior to the final merger. For ultracompact white dwarf binaries, we find that unipolar induction does not provide adequate energy dissipation to explain the observed X-ray luminosities of several sources. For exoplanetary systems containing close-in Jupiters or super-Earths, the magnetic torque and energy dissipation induced by the orbital motion are negligible, except possibly during the early T Tauri phase, when the stellar magnetic field is stronger than 10{sup 3} G.
Umbrella: a unified software defined development framework

The Northbound (NB) APIs that SDN controllers provide differ in terms of architecture, syntax, naming convention, data resources, and usage. Using NB APIs to write SDN applications makes each application dependent on the API of a specific controller. To bring NB APIs from different vendors under one umbrella and make programming of SDN applications independent of specific controllers, we propose a unified software defined development framework that we call Umbrella. This paper presents the key components of the software and reports some preliminary results.
All-multiplicity one-loop amplitudes in Born-Infeld electrodynamics from generalized unitarity

We initiate a study of non-supersymmetric Born-Infeld electrodynamics in 4d at the quantum level. Explicit all-multiplicity expressions are calculated for the purely rational one-loop amplitudes in the self-dual (+ + … +) and next-to-self-dual (− + … +) helicity sectors. Using a supersymmetric decomposition, d-dimensional unitarity cuts of the integrand factorize into tree-amplitudes in a 4d model of Born-Infeld photons coupled to a massive complex scalar. The two-scalar tree-amplitudes needed to construct the Born-Infeld integrand are computed using two complimentary approaches: (1) as a double-copy of Yang-Mills coupled to a massive adjoint scalar with a dimensionally reduced form of Chiral Perturbation Theory, and (2) by imposing consistency with low-energy theorems under a reduction from 4d to 3d and T-duality. The Born-Infeld integrand is integrated in d = 4 − 2ϵ dimensions at order $$ \mathcal{O}\left({\in}^0\right) $$ using the dimension-shifting formalism. We comment on the implications for electromagnetic duality in quantum Born-Infeld theory.
Adiabatic limits of Ricci-flat Kähler metrics

We study adiabatic limits of Ricci-flat Kahler metrics on a Calabi-Yau manifold which is the total space of a holomorphic fibration when the volume of the fibers goes to zero. By establishing some new a priori estimates for the relevant complex Monge-Ampere equation, we show that the Ricci-flat metrics collapse (away from the singular fibers) to a metric on the base of the fibration. This metric has Ricci curvature equal to a Weil- Petersson metric that measures the variation of complex structure of the Calabi-Yau fibers. This generalizes results of Gross-Wilson for $K3$ surfaces to higher dimensions.
Interferometric Evidence for Resolved Warm Dust in the DQ Tau System

We report on near-infrared (IR) interferometric observations of the double-lined pre-main sequence binary system DQ Tau. We model these data with a visual orbit for DQ Tau supported by the spectroscopic orbit and analysis of Mathieu et al. Further, DQ Tau exhibits significant near-IR excess; modeling our data requires inclusion of near-IR light from an "excess" source. Remarkably, the excess source is resolved in our data, similar in scale to the binary itself (~0.2 AU at apastron), rather than the larger circumbinary disk (~0.4 AU radius). Our observations support the Mathieu et al. and Carr et al. inference of significant warm material near the DQ Tau binary.
Chiral stabilization of the renormalization group for flavor and color anisotropic current interactions

Abstract We propose an all-orders β-function for current–current interactions in 2d with flavor anisotropy. When the number of left-moving and right-moving flavors are unequal, the β-function has a nontrivial fixed point at finite values of the couplings. We also extend the computation to simple cases with both flavor and color anisotropy.
How to Find Variable Active Galactic Nuclei with Machine Learning

Machine-learning (ML) algorithms will play a crucial role in studying the large data sets delivered by new facilities over the next decade and beyond. Here, we investigate the capabilities and limits of such methods in finding galaxies with brightness-variable active galactic nuclei (AGNs). Specifically, we focus on an unsupervised method based on self-organizing maps (SOM) that we apply to a set of nonparametric variability estimators. This technique allows us to maintain domain knowledge and systematics control while using all the advantages of ML. Using simulated light curves that match the noise properties of observations, we verify the potential of this algorithm in identifying variable light curves. We then apply our method to a sample of ~8300 WISE color-selected AGN candidates in Stripe 82, in which we have identified variable light curves by visual inspection. We find that with ML we can identify these variable classified AGN with a purity of 86% and a completeness of 66%, a performance that is comparable to that of more commonly used supervised deep-learning neural networks. The advantage of the SOM framework is that it enables not only a robust identification of variable light curves in a given data set, but it is also a tool to investigate correlations between physical parameters in multidimensional space—such as the link between AGN variability and the properties of their host galaxies. Finally, we note that our method can be applied to any time-sampled light curve (e.g., supernovae, exoplanets, pulsars, and other transient events).
Diffusion maps for changing data

Abstract Graph Laplacians and related nonlinear mappings into low dimensional spaces have been shown to be powerful tools for organizing high dimensional data. Here we consider a data set X in which the graph associated with it changes depending on some set of parameters. We analyze this type of data in terms of the diffusion distance and the corresponding diffusion map. As the data changes over the parameter space, the low dimensional embedding changes as well. We give a way to go between these embeddings, and furthermore, map them all into a common space, allowing one to track the evolution of X in its intrinsic geometry. A global diffusion distance is also defined, which gives a measure of the global behavior of the data over the parameter space. Approximation theorems in terms of randomly sampled data are presented, as are potential applications.
Water Reaction Mechanism in Metal Organic Frameworks with Coordinatively Unsaturated Metal Ions: MOF-74

Water dissociation represents one of the most important reactions in catalysis, essential to the surface and nano sciences [e.g., Hass et al., Science, 1998, 282, 265–268; Brown et al., Science, 2001, 294, 67–69; Bikondoa et al., Nature, 2005, 5, 189–192]. However, the dissociation mechanism on most oxide surfaces is not well understood due to the experimental challenges of preparing surface structures and characterizing reaction pathways. To remedy this problem, we propose the metal organic framework MOF-74 as an ideal model system to study water reactions. Its crystalline structure is well characterized; the metal oxide node mimics surfaces with exposed cations; and it degrades in water. Combining in situ IR spectroscopy and first-principles calculations, we explored the MOF-74/water interaction as a function of vapor pressure and temperature. Here, we show that, while adsorption is reversible below the water condensation pressure (∼19.7 Torr) at room temperature, a reaction takes place at ∼150 °C even ...
Memory Based Trajectory-conditioned Policies for Learning from Sparse Rewards

Reinforcement learning with sparse rewards is challenging because an agent can rarely obtain non-zero rewards and hence, gradient-based optimization of parameterized policies can be incremental and slow. Recent work demonstrated that using a memory buffer of previous successful trajectories can result in more effective policies. However, existing methods may overly exploit past successful experiences, which can encourage the agent to adopt sub-optimal and myopic behaviors. In this work, instead of focusing on good experiences with limited diversity, we propose to learn a trajectory-conditioned policy to follow and expand diverse past trajectories from a memory buffer. Our method allows the agent to reach diverse regions in the state space and improve upon the past trajectories to reach new states. We empirically show that our approach significantly outperforms count-based exploration methods (parametric approach) and self-imitation learning (parametric approach with non-parametric memory) on various complex tasks with local optima. In particular, without using expert demonstrations or resetting to arbitrary states, we achieve the state-of-the-art scores under five billion number of frames, on challenging Atari games such as Montezuma's Revenge and Pitfall.
A digital interface for Gaussian relay networks: lifting codes from the discrete superposition model to Gaussian relay networks

For every Gaussian relay network with a single source-destination pair, it is known that there exists a corresponding deterministic network called the discrete superposition network [1] that approximates its capacity uniformly over all SNR's to within a bounded number of bits. The next step in this program of rigorous approximation is to determine whether coding schemes for discrete superposition models can be lifted to Gaussian relay networks with a bounded rate loss independent of SNR. We establish precisely this property and show that the superposition model can thus serve as a strong surrogate for designing codes for Gaussian relay networks.
Embeddings and time evolution of the Schwarzschild wormhole

We show how to embed spacelike slices of the Schwarzschild wormhole (or Einstein-Rosen bridge) in R3. Graphical images of embeddings are given, including depictions of the dynamics of this nontraversable wormhole at constant Kruskal times up to and beyond the “pinching off” at Kruskal times ±1.
Curves over every global field violating the local-global principle

There is an algorithm that takes as input a global field k and produces a curve over k violating the local-global principle. Also, given a global field k and a nonnegative integer n, one can effectively construct a curve X over k such that #X(k) = n. Bibliography: 26 titles.
The Signature of Single-Degenerate Accretion Induced Collapse

The accretion-induced collapse (AIC) of a white dwarf to a neutron star has long been suggested as a natural theoretical outcome in stellar evolution, but there has never been a direct detection of such an event. This is not surprising since the small amount of radioactive nickel synthesized (~10^(−3) M_☉) implies a relatively dim optical transient. Here we argue that a particularly strong signature of an AIC would occur for an oxygen–neon–magnesium (ONeMg) white dwarf accreting from a star that is experiencing Roche-lobe overflow as it becomes a red giant. In such cases, the ~10^(50) erg explosion from the AIC collides with and shock-heats the surface of the extended companion, creating an X-ray flash lasting ~1 hr followed by an optical signature that peaks at an absolute magnitude of ~ −16 to −18 and lasts for a few days to a week. These events would be especially striking in old stellar environments where hydrogen-rich supernova-like transients would not normally be expected. Although the rate of such events is not currently known, we describe observing strategies that could be utilized with high cadence surveys that should either detect these events or place strong constraints on their rates.
A WISE Census of Young Stellar Objects in Canis Major

With the Wide-Field Infrared Survey Explorer (WISE), we searched for young stellar objects (YSOs) in a 100 deg^2 region centered on the lightly studied Canis Major star forming region. Applying stringent magnitude cuts to exclude the majority of extragalactic contaminants, we find 144 Class I candidates and 335 Class II candidates. The sensitivity to Class II candidates is limited by their faintness at the distance to Canis Major (assumed as 1000 pc). More than half the candidates (53%) are found in 16 groups of more than four members, including four groups with more than 25 members each. The ratio of Class II to Class I objects, N_II/N_I, varies from 0.4 to 8.3 in just the largest four groups. We compare our results to those obtainable with combined Two Micron All Sky Survey (2MASS) and post-cryogenic Spitzer Space Telescope data; the latter approach recovers missing Class II sources. Via a comparison to protostars characterized with the Herschel Space Observatory, we propose new WISE color criteria for flat-spectrum and Class 0 protostars, finding 80 and seven of these, respectively. The distribution of YSOs in CMa OB1 is consistent with supernova-induced star formation, although the diverse N_II/N_I ratios are unexpected if this parameter traces age and the YSOs are due to the same supernova. Less massive clouds feature larger N_II/N_I ratios, suggesting that initial conditions play a role in determining this quantity.
Differential formulation of the gyrokinetic Landau operator

Subsequent to the recent rigorous derivation of an energetically consistent gyrokinetic collision operator in the so-called Landau representation, this paper investigates the possibility of finding a differential formulation of the gyrokinetic Landau collision operator. It is observed that, while a differential formulation is possible in the gyrokinetic phase space, reduction of the resulting system of partial differential equations to five dimensions via gyroaveraging poses a challenge. Based on the present work, it is likely that the gyrocentre analogues of the Rosenbluth–MacDonald–Judd potential functions must be kept gyroangle dependent.
Variable flavor number schemes versus fixed order perturbation theory for charm quark electroproduction

Data for \(D^{*\pm}(2010)\) meson electroproduction in the range \(10 1 \; {\rm GeV}^2\) to test whether one can distinguish between different theoretical schemes for charm quark electroproduction. We find that up to the largest \(Q^2\) measured, it is not possible to make such a differentiation. Then we point out the regions where differences between the various schemes arise.
Exclusive signals of an extended Higgs sector

Expectations for the magnitude of Higgs boson signals in standard Higgs search channels at the LHC relative to Standard Model (SM) expectations are investigated within the framework of various types of CP and flavor conserving two Higgs doublet models (2HDMs). Signals of the SM-like Higgs boson in different classes of 2HDM may be parameterized in terms of particular two-dimensional sub-spaces of the general four-dimensional space of Higgs couplings to the massive vector bosons, top quark, bottom quark, and tau lepton. We find fairly strong correlations among the inclusive di-photon channel and the exclusive di-photon and di-tau channels from vector boson fusion or associated production. Order one deviations from SM expectations in some of these channels could provide discriminating power among various types of 2HDMs. The ratio of exclusive di-photon to di-tau channels is particularly sensitive to deviations from SM expectations. We also emphasize that deviations from SM expectations in standard Higgs search channels may imply observable signals of non-SM-like Higgs bosons in some of these same channels, in particular in di-photon and di-vector boson channels. The results cataloged here provide a roadmap for interpreting standard Higgs search channels in the context of 2HDMs.
Bootstrapped Q-learning with Context Relevant Observation Pruning to Generalize in Text-based Games

We show that Reinforcement Learning (RL) methods for solving Text-Based Games (TBGs) often fail to generalize on unseen games, especially in small data regimes. To address this issue, we propose Context Relevant Episodic State Truncation (CREST) for irrelevant token removal in observation text for improved generalization. Our method first trains a base model using Q-learning, which typically overfits the training games. The base model’s action token distribution is used to perform observation pruning that removes irrelevant tokens. A second bootstrapped model is then retrained on the pruned observation text. Our bootstrapped agent shows improved generalization in solving unseen TextWorld games, using 10x-20x fewer training games compared to previous state-of-the-art (SOTA) methods despite requiring fewer number of training episodes.
FFRob: Leveraging symbolic planning for efficient task and motion planning:

Mobile manipulation problems involving many objects are challenging to solve due to the high dimensionality and multi-modality of their hybrid configuration spaces. Planners that perform a purely g...
Asymptotic Boundary Observability for the Wave Equation on One Side of a Planar Triangle

We consider the wave equation $$(\partial _t^2-\Delta )u=0$$ on a planar triangular domain $$\Omega \subset \mathbb {R}^2$$ with Dirichlet boundary conditions. We use a commutator and integration by parts argument similar to that in Christianson (Proc Am Math Soc 145(12):5247–5255, 2017) by the first author to obtain an observability asymptotic for any one side of the triangle. Our result is particular to triangular domains and does not hold for polygons in general.
Laser-cooled polyatomic molecules for improved electron electric dipole moment searches

Doppler and Sisyphus cooling of $^{174}$YbOH are achieved and studied. This polyatomic molecule has high sensitivity to physics beyond the Standard Model and represents a new class of species for future high-precision probes of new T-violating physics. The transverse temperature of the YbOH beam is reduced by nearly two orders of magnitude to $ 6$ via Sisyphus cooling. We develop a full numerical model of the laser cooling of YbOH and find excellent agreement with the data. We project that laser cooling and magneto-optical trapping of long-lived samples of YbOH molecules are within reach and these will allow a high sensitivity probe of the electric dipole moment (EDM) of the electron. The approach demonstrated here is easily generalized to other isotopologues of YbOH that have enhanced sensitivity to other symmetry-violating electromagnetic moments.
An ignoble approach to large field inflation

We study an inflationary model developed by Kaloper and Sorbo, in which the inflaton is an axion with a sub-Planckian decay constant, whose potential is generated by mixing with a topological 4-form field strength. This gives a 4d construction of ``axion monodromy inflation: the axion winds many times over the course of inflation and draws energy from the 4-form. The classical theory is equivalent to chaotic inflation with a quadratic inflaton potential. Such models can produce ``high scale inflation driven by energy densities of the order of (1016GeV)4, which produces primordial gravitational waves potentially accessible to CMB polarization experiments. We analyze the possible corrections to this scenario from the standpoint of 4d effective field theory, identifying the physics which potentially suppresses dangerous corrections to the slow-roll potential. This yields a constraint relation between the axion decay constant, the inflaton mass, and the 4-form charge. We show how these models can evade the fundamental constraints which typically make high-scale inflation difficult to realize. Specifically, the moduli coupling to the axion-four-form sector must have masses higher than the inflationary Hubble scale (1014GeV). There are also constraints from states that become light due to multiple windings of the axion, as happens in explicit string theory constructions of this scenario. Further, such models generally have a quantum-mechanical ``tunneling mode in which the axion jumps between windings, which must be suppressed. Finally, we outline possible observational signatures.
Equivariant group presentations and the second homology group of the Torelli group

We develop a theory of equivariant group presentations and relate them to the second homology group of a group. Our main application says that the second homology group of the Torelli subgroup of the mapping class group is finitely generated as a $$\mathbb {Z}[{{\,\mathrm{Sp}\,}}_{2g}(\mathbb {Z})]$$-module.
A compact superconducting nanowire memory element operated by nanowire cryotrons

A superconducting loop stores persistent current without any ohmic loss, making it an ideal platform for energy efficient memories. Conventional superconducting memories use an architecture based on Josephson junctions (JJs) and have demonstrated access times less than 10 ps and power dissipation as low as 10−19 J. However, their scalability has been slow to develop due to the challenges in reducing the dimensions of JJs and minimizing the area of the superconducting loops. In addition to the memory itself, complex readout circuits require additional JJs and inductors for coupling signals, increasing the overall area. Here, we have demonstrated a superconducting memory based solely on lithographic nanowires. The small dimensions of the nanowire ensure that the device can be fabricated in a dense area in multiple layers, while the high kinetic inductance makes the loop essentially independent of geometric inductance, allowing it to be scaled down without sacrificing performance. The memory is operated by a group of nanowire cryotrons patterned alongside the storage loop, enabling us to reduce the entire memory cell to 3 μm × 7 μm in our proof-of-concept device. In this work we present the operation principles of a superconducting nanowire memory (nMem) and characterize its bit error rate, speed, and power dissipation.
Scaling of Harmonic Oscillator Eigenfunctions and Their Nodal Sets Around the Caustic

We study the scaling asymptotics of the eigenspace projection kernels \({\Pi_{\hbar, E}(x,y)}\) of the isotropic Harmonic Oscillator \({\hat{H}_{\hbar} = - \hbar^2 \Delta +|x|^2}\) of eigenvalue \({E = \hbar(N + \frac{d}{2})}\) in the semi-classical limit \({\hbar \to 0}\) . The principal result is an explicit formula for the scaling asymptotics of \({\Pi_{\hbar, E}(x,y)}\) for x, y in a \({\hbar^{2/3}}\) neighborhood of the caustic \({\mathcal{C}_E}\) as \({\hbar \rightarrow 0.}\) The scaling asymptotics are applied to the distribution of nodal sets of Gaussian random eigenfunctions around the caustic as \({\hbar \to 0}\) . In previous work we proved that the density of zeros of Gaussian random eigenfunctions of \({\hat{H}_{\hbar}}\) have different orders in the Planck constant \({\hbar}\) in the allowed and forbidden regions: In the allowed region the density is of order \({\hbar^{-1}}\) while it is \({\hbar^{-1/2}}\) in the forbidden region. Our main result on nodal sets is that the density of zeros is of order \({\hbar^{-\frac{2}{3}}}\) in an \({\hbar^{\frac{2}{3}}}\) -tube around the caustic. This tube radius is the ‘critical radius’. For annuli of larger inner and outer radii \({\hbar^{\alpha}}\) with \({0 < \alpha < \frac{2}{3}}\) we obtain density results that interpolate between this critical radius result and our prior ones in the allowed and forbidden region. We also show that the Hausdorff (d−2)-dimensional measure of the intersection of the nodal set with the caustic is of order \({\hbar^{- \frac{2}{3}}}\) .
Detection and isolation of link failures under the agreement protocol

In this paper a property of the multi-agent consensus dynamics that relates the failure of links in the network to jump discontinuities in the derivatives of the output responses of the nodes is derived and verified analytically. At the next step, an algorithm for sensor placement is proposed, which would enable the designer to detect and isolate any link failures across the network based on the observed jump discontinuities in the derivatives of the responses of a subset of nodes. These results are explained through elaborative examples.
The Effects of Noise and Sampling on the Spectral Correlation Function

The effects of noise and sampling on the spectral correlation function (SCF) introduced by Rosolowsky and coworkers are studied using observational data, numerical simulations of magnetohydrodynamic turbulence, and simple models of Gaussian spectral line profiles. The most significant innovations of this paper are (1) the normalization of the SCF based on an analytic model for the effect of noise and (2) the computation of the SCF as a function of the spatial lag between spectra within a map. A new definition of the "quality" of a spectrum, Q, is introduced, which is correlated with the usual definition of signal-to-noise ratio. The prenormalization value of the SCF is a function of Q. We derive analytically the effect of noise on the SCF, and then normalize the SCF to its analytic approximation. By computing the dependence of the SCF on the spatial lag, S0(Δr), we have been able to conclude the following: (1) S0(Δr) is a power law, with slope α, in the range of scales li < l < lo. (2) The correlation outer scale, lo, is determined by the size of the map, and no evidence for a true departure from self-similarity on large scales has been found. (3) The correlation inner scale, li, is a true estimate of the smallest self-similar scale in a map. (4) The spectral slope, α, in a given region, is independent of velocity resolution (above a minimum resolution threshold), spatial resolution, and average spectrum quality. (5) Molecular transitions that trace higher gas density yield larger values of α (steeper slopes) than transitions tracing lower gas density. (6) Nyquist sampling, bad pixels in detector arrays, and reference-sharing data acquisition need to be taken into account for a correct determination of the SCF at Δr = 1. The value of α, however, can be computed correctly without a detailed knowledge of observational procedures.
Learning the Alpha-bits of black holes

When the bulk geometry in AdS/CFT contains a black hole, boundary subregions may be sufficient to reconstruct certain bulk operators if and only if the black hole microstate is known, an example of state dependence. Reconstructions exist for any microstate, but no reconstruction works for all microstates. We refine this dichotomy, demonstrating that the same boundary operator can often be used for large subspaces of black hole microstates, corresponding to a constant fraction α of the black hole entropy. In the Schrodinger picture, the boundary subregion encodes the α-bits (a concept from quantum information) of a bulk region containing the black hole and bounded by extremal surfaces. These results have important consequences for the structure of AdS/CFT and for quantum information. Firstly, they imply that the bulk reconstruction is necessarily only approximate and allow us to place non-perturbative lower bounds on the error when doing so. Second, they provide a simple and tractable limit in which the entanglement wedge is state dependent, but in a highly controlled way. Although the state dependence of operators comes from ordinary quantum error correction, there are clear connections to the Papadodimas-Raju proposal for understanding operators behind black hole horizons. In tensor network toy models of AdS/CFT, we see how state dependence arises from the bulk operator being ‘pushed’ through the black hole itself. Finally, we show that black holes provide the first ‘explicit’ examples of capacity-achieving α-bit codes. Unintuitively, Hawking radiation always reveals the α-bits of a black hole as soon as possible. In an appendix, we apply a result from the quantum information literature to prove that entanglement wedge reconstruction can be made exact to all orders in 1/N.
A Spectroscopic Census of X-Ray Systems in the COSMOS Field

We investigate spectroscopic properties of galaxy systems identified based on deep X-ray observations in the COSMOS field. The COSMOS X-ray system catalog we use George et al. (2011) includes 180 X-ray systems to a limiting flux of $1.0 \times 10^{-15}$ erg cm$^{-2}$ s$^{-1}$, an order of magnitude deeper than future e-ROSITA survey. We identify spectroscopic members of these X-ray systems based on the spectroscopic catalog constructed by compiling various spectroscopic surveys including 277 new measurements; 137 X-ray systems are spectroscopically identified groups with more than three spectroscopic members. We identify 1843 spectroscopic redshifts of member candidates in these X-ray systems. The X-ray luminosity ($L_{X}$) - velocity dispersion ($\sigma_{v}$) scaling relation of the COSMOS X-ray systems is consistent with that of massive X-ray clusters. One of the distinctive features of the COSMOS survey is that it covers the X-ray luminosity range where poor groups overlap the range for extended emission associated with individual quiescent galaxies. We assess the challenges posed by the complex morphology of the distribution of low X-ray luminosity systems, including groups and individual quiescent galaxies, in the $L_{x} - \sigma_{v}$ plane.
Time-dependent Models of Magnetospheric Accretion onto Young Stars

Accretion onto Classical T Tauri stars is thought to take place through the action of magnetospheric processes, with gas in the inner disk being channeled onto the star's surface by the stellar magnetic field lines. Young stars are known to accrete material in a time-variable manner, and the source of this variability remains an open problem, particularly on the shortest (~day) timescales. Using one-dimensional time-dependent numerical simulations that follow the field line geometry, we find that for plausibly realistic young stars, steady-state transonic accretion occurs naturally in the absence of any other source of variability. However, we show that if the density in the inner disk varies smoothly in time with ~day-long timescales (e.g., due to turbulence), this complication can lead to the development of shocks in the accretion column. These shocks propagate along the accretion column and ultimately hit the star, leading to rapid, large amplitude changes in the accretion rate. We argue that when these shocks hit the star, the observed time dependence will be a rapid increase in accretion luminosity, followed by a slower decline, and could be an explanation for some of the short-period variability observed in accreting young stars. Our one-dimensional approach bridges previous analytic work to more complicated multi-dimensional simulations and observations.