cssi/SciSciGPT-SciSciNet huggingface dataset:
Proof of the Weak Gravity Conjecture from Black Hole Entropy

We prove that higher-dimension operators contribute positively to the entropy of a thermodynamically stable black hole at fixed mass and charge. Our results apply whenever the dominant corrections originate at tree level from quantum field theoretic dynamics. More generally, positivity of the entropy shift is equivalent to a certain inequality relating the free energies of black holes. These entropy inequalities mandate new positivity bounds on the coefficients of higher-dimension operators. One of these conditions implies that the charge-to-mass ratio of an extremal black hole asymptotes to unity from above for increasing mass. Consequently, large extremal black holes are unstable to decay to smaller extremal black holes and the weak gravity conjecture is automatically satisfied. Our findings generalize to arbitrary spacetime dimension and to the case of multiple gauge fields. The assumptions of this proof are valid across a range of scenarios, including string theory constructions with a dilaton stabilized below the string scale.
Universal polynomials for singular curves on surfaces

Let is sufficiently ample. More generally, we show for vector bundles of any rank and smooth varieties of any dimension, similar universal polynomials also exist and equal the number of singular subvarieties cutting out by sections of the vector bundle. This work is a generalization of Gottsche’s conjecture.
Realization of a high mobility dual-gated graphene field-effect transistor with Al2O3 dielectric

We fabricate and characterize dual-gated graphene field-effect transistors using Al2O3 as top-gate dielectric. We use a thin Al film as a nucleation layer to enable the atomic layer deposition of Al2O3. Our devices show mobility values of over 8000 cm2/V s at room temperature, a finding which indicates that the top-gate stack does not significantly increase the carrier scattering and consequently degrade the device characteristics. We propose a device model to fit the experimental data using a single mobility value.
On the Missing Energy Puzzle of Tidal Disruption Events

For the majority of the tidal disruption event (TDE) candidates, the observed energy in the optical/near-UV bands is of order 10^{51} erg. We show that this observed energy is smaller than the minimum bolometric energy for the radiative inefficient accretion flow model by a factor of 10-100. We argue that this discrepancy is because the majority of the energy released is in the extreme-UV (EUV) band and/or in the form of relativistic jets beamed away from the Earth. The EUV scenario is supported by existing mid-infrared data and should be further tested by future dust reverberation observations. The jet scenario is disfavored by the radio observations of ASASSN-14li but may still be viable for other TDE candidates. We also provide evidence that, at least for some TDEs, most of the missing energy (in the EUV and/or in the form of jets) is released within a few times the orbital period of the most tightly bound material, which means (1) the circularization of the fallback stream may occur rapidly, and (2) the luminosity of the accretion flow or the jet power may not be capped near the Eddington level when the fallback rate is super-Eddington. For most other TDEs, this energy-release timescale is currently not strongly constrained.
Semisymmetric polynomials and the invariant theory of matrix vector pairs

In this paper we introduce and investigate a one-parameter family of polynomials. They are semisymmetric, i.e. symmetric in the variables with odd and even index separately. In fact, the family forms a basis of the space of semisymmetric polynomials. For two values of the parameter r, namely r=1/2 and r=1, the polynomials have a representation theoretic meaning. In general, they form the semisymmetric analogue of (shifted) Jack polynomials.
Heegaard diagrams and surgery descriptions for twisted face-pairing 3-manifolds

The twisted face-pairing construction of our earlier papers gives an ecient way of generating, mechanically and with little eort, myriads of relatively simple face-pairing descriptions of interesting closed 3-manifolds. The corresponding description in terms of surgery, or Dehn-lling, reveals the twist construction as a carefully organized surgery on a link. In this paper, we work out the relationship between the twisted face-pairing description of closed 3-manifolds and the more common descriptions by surgery and Heegaard diagrams. We show that all Heegaard diagrams have a natural decomposition into subdiagrams called Heegaard cylinders, each of which has a natural shape given by the ratio of two positive integers. We characterize the Heegaard diagrams arising naturally from a twisted face-pairing description as those whose Heegaard cylinders all have inte- gral shape. This characterization allows us to use the Kirby calculus and standard tools of Heegaard theory to attack the problem of nding which closed, orientable 3-manifolds have a twisted face-pairing description.
Unsaturated hydraulic conductivity models based on truncated lognormal pore-size distributions.

We develop a closed-form three-parameter model for unsaturated hydraulic conductivity associated with the Kosugi three-parameter lognormal moisture retention model. The model derivation uses a slight modification to Mualem's theory, which is nearly exact for nonclay soils. Kosugi's three-parameter lognormal moisture retention model uses physically meaningful parameters, but a corresponding closed-form relative hydraulic conductivity model has never been developed. The model is further extended to a four-parameter model by truncating the underlying pore-size distribution at physically permissible minimum and maximum pore radii. The proposed closed-form models are fitted to well-known experimental data to illustrate their utility. They have the same physical basis as Kosugi's two-parameter model, but are more general.
Generalized hidden Kerr/CFT

We construct a family of vector fields that generate local symmetries in the solution space of low frequency massless field perturbations in the general Kerr geometry. This yields a one-parameter family of algebras. We identify limits in which the algebra contracts to an symmetry of the Schwarzschild background. We note that for a particular value of the free parameter, the symmetry algebra generates the quasinormal mode spectrum of a Kerr black hole in the large damping limit, suggesting a connection between the hidden conformal symmetry and a fundamental conformal field theory underlying the quantum Kerr black hole.
Reconstruction of protein structures from single-molecule time series.

Single-molecule experimental techniques track the real-time dynamics of molecules by recording a small number of experimental observables. Following these observables provides a coarse-grained, low-dimensional representation of the conformational dynamics but does not furnish an atomistic representation of the instantaneous molecular structure. Takens’s delay embedding theorem asserts that, under quite general conditions, these low-dimensional time series can contain sufficient information to reconstruct the full molecular configuration of the system up to an a priori unknown transformation. By combining Takens’s theorem with tools from statistical thermodynamics, manifold learning, artificial neural networks, and rigid graph theory, we establish an approach, Single-molecule TAkens Reconstruction, to learn this transformation and reconstruct molecular configurations from time series in experimentally measurable observables such as intramolecular distances accessible to single molecule Forster resonance energy transfer. We demonstrate the approach in applications to molecular dynamics simulations of a C24H50 polymer chain and the artificial mini-protein chignolin. The trained models reconstruct molecular configurations from synthetic time series data in the head-to-tail molecular distances with atomistic root mean squared deviation accuracies better than 0.2 nm. This work demonstrates that it is possible to accurately reconstruct protein structures from time series in experimentally measurable observables and establishes the theoretical and algorithmic foundations to do so in applications to real experimental data.
The Local Perspective on the Hubble Tension: Local Structure Does Not Impact Measurement of the Hubble Constant

We use the largest sample to date of spectroscopic supernova (SN) Ia distances and redshifts to look for evidence in the Hubble diagram of large-scale outflows caused by local voids suggested to exist at z < 0.15. Our sample combines data from the Pantheon sample with the Foundation survey, and the most recent release of light curves from the Carnegie Supernova Project, to create a sample of 1295 SNe over a redshift range of 0.01 < z < 2.26. We make use of an inhomogeneous and isotropic Lemaitre–Tolman–Bondi metric to model a void in the SN Ia distance–redshift relation. We conclude that the SN luminosity distance–redshift relation is inconsistent at the 4–5σ confidence level with large local underdensities (, where the density contrast δ = Δρ/ρ) proposed in some galaxy count studies, and find no evidence of a change in the Hubble constant corresponding to a void with a sharp edge in the redshift range 0.023 < z < 0.15. With an empirical precision of , we conclude that the distance ladder measurement is not affected by local density contrasts, in agreement with a cosmic variance of , predicted from simulations of large-scale structure. Given that uncertainty in the distance ladder value is , this does not affect the Hubble tension. We derive a 5σ constraint on local density contrasts on scales larger than of . The presence of local structure does not appear to impede the possibility of measuring the Hubble constant to 1% precision.
Experimental Status of the CKM Matrix

The CKM matrix, VV, relates the quark mass and flavor bases. In the standard model, VV is unitary 3×3, and specified by four arbitrary parameters, including a phase allowing for CPCP violation. We review the experimental determination of VV, including the four parameters in the standard model context. This is an active field; the precision of experimental measurements and theoretical inputs continues to improve. The consistency of the determination with the standard model unitarity is investigated. While there remain some issues the overall agreement with standard model unitarity is good.
Value Driven Representation for Human-in-the-Loop Reinforcement Learning

Interactive adaptive systems powered by Reinforcement Learning (RL) have many potential applications, such as intelligent tutoring systems. In such systems there is typically an external human system designer that is creating, monitoring and modifying the interactive adaptive system, trying to improve its performance on the target outcomes. In this paper we focus on algorithmic foundation of how to help the system designer choose the set of sensors or features to define the observation space used by reinforcement learning agent to make decisions. We present an algorithm, value driven representation (VDR), that can iteratively and adaptively augment the observation space of a reinforcement learning agent so that is sufficient to capture a (near) optimal policy. To do so we introduce a new method to optimistically estimate the value of a policy using offline simulated Monte Carlo rollouts. We evaluate the performance of our approach on standard RL benchmarks with simulated humans and demonstrate significant improvement over prior baselines.
The Turbulence Velocity Power Spectrum of Neutral Hydrogen in the Small Magellanic Cloud

We present the results of the Velocity Coordinate Spectrum (VCS) technique to calculate the velocity power spectrum of turbulence in the Small Magellanic Cloud (SMC) in 21 cm emission. We present an updated version of the VCS technique that takes into account regular motions, which is an important factor in our SMC VCS analysis. We have obtained a velocity spectral index of −3.85, a cold phase sonic Mach number of 5.6, and an injection scale of 2.3 kpc. The spectral index is steeper than the Kolmogorov index, which is expected for shock-dominated turbulence. The injection scale of 2.3 kpc suggests that HI supershells or tidal interactions with the Large Magellanic Cloud are the dominant drivers of turbulence in this dwarf galaxy. This implies that turbulence may be driven by multiple mechanisms in galaxies and that galaxy–galaxy interactions may play an important role in addition to supernova feedback.
Mean-field theory for global binding systematics

We review some possible improvements of mean-field theory for application to nuclear-binding systematics. Up to now, microscopic theory has been less successful than models starting from the liquid drop in accurately describing the global binding systematics. We believe that there are good prospects for developing a better global theory, using modern forms of energy-density functionals and treating correlation energies systematically by the RPA.
Adaptive mesh refinement for characteristic grids

I consider techniques for Berger–Oliger adaptive mesh refinement (AMR) when numerically solving partial differential equations with wave-like solutions, using characteristic (double-null) grids. Such AMR algorithms are naturally recursive, and the best-known past Berger–Oliger characteristic AMR algorithm, that of Pretorius and Lehner (J Comp Phys 198:10, 2004), recurses on individual “diamond” characteristic grid cells. This leads to the use of fine-grained memory management, with individual grid cells kept in two-dimensional linked lists at each refinement level. This complicates the implementation and adds overhead in both space and time. Here I describe a Berger–Oliger characteristic AMR algorithm which instead recurses on null slices. This algorithm is very similar to the usual Cauchy Berger–Oliger algorithm, and uses relatively coarse-grained memory management, allowing entire null slices to be stored in contiguous arrays in memory. The algorithm is very efficient in both space and time. I describe discretizations yielding both second and fourth order global accuracy. My code implementing the algorithm described here is included in the electronic supplementary materials accompanying this paper, and is freely available to other researchers under the terms of the GNU general public license.
Non-spherical equilibrium shapes in the liquid drop model

We prove the existence of a family of volume-constrained critical points of the liquid drop functional, which are cylindrically but not spherically symmetric. This family bifurcates from the ball and exchanges stability with it. We justify a formula of Bohr and Wheeler for the energy of these sets.
Does Low-Frequency X-Ray QPO Behavior in GRS 1915+105 Influence Subsequent X-Ray and Infrared Evolution?

Using observations with the Rossi X-Ray Timing Explorer, we examine the behavior of 2-10 Hz quasi-periodic oscillations (QPOs) during spectrally hard dips in the X-ray light curve of GRS 1915+105 that are accompanied by infrared flares. Of the 12 light curves examined, 9 are β class and three are α class, following the scheme of Belloni et al. In most cases, the QPO frequency is most strongly correlated to the power-law flux, which partially contradicts some earlier claims that the strongest correlation is between QPO frequency and blackbody flux. Seven β-class curves are highly correlated to blackbody features. In several cases, the QPO evolution appears to decouple from the spectral evolution. We find that β-class light curves with strong correlations can be distinguished from those without by their "trigger spike" morphology. We also show that the origin and strength of the subsequent infrared flare may be causally linked to the variations in QPO frequency evolution and not solely tied to the onset of soft X-ray flaring behavior. We divide the 12 α- and β-class light curves into three groups based on the evolution of the QPO, the morphology of the trigger spike, and the infrared flare strength. An apparent crossover case leads us to conclude that these groups are not unique modes but represent part of a continuum of accretion behaviors. We believe the QPO behavior at the initiation of the hard dip can ultimately be used to determine the terminating X-ray behavior and the following infrared flaring behavior.
Accurate non-adiabatic quantum dynamics from pseudospectral sampling of time-dependent Gaussian basis sets

Quantum molecular dynamics requires an accurate representation of the molecular potential energy surface from a minimal number of electronic structure calculations, particularly for nonadiabatic dynamics where excited states are required. In this paper, we employ pseudospectral sampling of time-dependent Gaussian basis functions for the simulation of non-adiabatic dynamics. Unlike other methods, the pseudospectral Gaussian molecular dynamics tests the Schrodinger equation with N Dirac delta functions located at the centers of the Gaussian functions reducing the scaling of potential energy evaluations from O(N2) to O(N). By projecting the Gaussian basis onto discrete points in space, the method is capable of efficiently and quantitatively describing the nonadiabatic population transfer and intra-surface quantum coherence. We investigate three model systems: the photodissociation of three coupled Morse oscillators, the bound state dynamics of two coupled Morse oscillators, and a two-dimensional model for co...
Ioffe time in double logarithmic approximation

Abstract We analyze the light cone (Ioffe) time structure of the gluon distribution function in the double logarithmic approximation. We show that due to QCD evolution Ioffe equation is modified. The characteristic light cone time of the gluons does not increase as fast with increasing energy (decreasing Bjorken x ) as predicted by the parton distributions exhibiting Bjorken scaling due to the increase of the transverse momenta of the gluons in the DGLAP ladder.
Empirical Green's function approach for utilizing millisecond focal and pupil plane telemetry in exoplanet imaging

Millisecond focal plane telemetry is now becoming practical due to a new generation of near-IR detector arrays with sub-electron noise that are capable of kHz readout rates. Combining these data with those simultaneously available from the wavefront sensing system allows the possibility of self-consistently determining the optical aberrations (the cause of quasi-static speckles) and the planetary image. This approach may be especially advantageous for finding planets within about 3λ/D of the star where differential imaging is ineffective. As shown in a recent article by the author (J. Opt. Soc. Am. A., 33, 712, 2016), one must account for unknown aberrations in several non-conjugate planes of the optical system, which, in turn, requires ability to computational propagate the field between these planes. These computations are likely to be difficult to implement and expensive. Here, a far more convenient alternative based on empirical Green's functions is provided. It is shown that the empirical Green's function (EGF), which accounts for all multi-planar, non-common path aberrations, and results in a much more tractable and highly parallel computational problem. It is also shown that the EGF can be generalized to treat polarization, resulting in the empirical Green's tensor (EGT).
End-To-End Projector Photometric Compensation

Projector photometric compensation aims to modify a projector input image such that it can compensate for disturbance from the appearance of projection surface. In this paper, for the first time, we formulate the compensation problem as an end-to-end learning problem and propose a convolutional neural network, named CompenNet, to implicitly learn the complex compensation function. CompenNet consists of a UNet-like backbone network and an autoencoder subnet. Such architecture encourages rich multi-level interactions between the camera-captured projection surface image and the input image, and thus captures both photometric and environment information of the projection surface. In addition, the visual details and interaction information are carried to deeper layers along the multi-level skip convolution layers. The architecture is of particular importance for the projector compensation task, for which only a small training dataset is allowed in practice. Another contribution we make is a novel evaluation benchmark, which is independent of system setup and thus quantitatively verifiable. Such benchmark is not previously available, to our best knowledge, due to the fact that conventional evaluation requests the hardware system to actually project the final results. Our key idea, motivated from our end-to-end problem formulation, is to use a reasonable surrogate to avoid such projection process so as to be setup-independent. Our method is evaluated carefully on the benchmark, and the results show that our end-to-end learning solution outperforms state-of-the-arts both qualitatively and quantitatively by a significant margin.
The syzygies of some thickenings of determinantal varieties

The vector space of m x n complex matrices (m >= n) admits a natural action of the group GL = GL_m x GL_n via row and column operations. For positive integers a,b, we consider the ideal I_{a x b} defined as the smallest GL-equivariant ideal containing the b-th powers of the a x a minors of the generic m x n matrix. We compute the syzygies of the ideals I_{a x b} for all a,b, together with their GL-equivariant structure, generalizing earlier results of Lascoux for the ideals of minors (b=1), and of Akin-Buchsbaum-Weyman for the powers of the ideals of maximal minors (a=n). Our methods rely on a nice connection between commutative algebra and the representation theory of the superalgebra gl(m|n), as well as on our previous calculation of Ext modules done in the context of describing local cohomology with determinantal support. Our results constitute an important ingredient in the proof by Nagpal-Sam-Snowden of the first non-trivial Noetherianity results for twisted commutative algebras which are not generated in degree one.
STRAIGHTENING THE DENSITY-DISPLACEMENT RELATION WITH A LOGARITHMIC TRANSFORM

We investigate the use of a logarithmic density variable in estimating the Lagrangian displacement field motivated by the success of a logarithmic transformation in restoring information to the matter power spectrum. The logarithmic relation is an extension of the linear relation, motivated by the continuity equation, in which the density field is assumed to be proportional to the divergence of the displacement field; we compare the linear and logarithmic relations by measuring both of these fields directly in a cosmological N-body simulation. The relative success of the logarithmic and linear relations depends on the scale at which the density field is smoothed. Thus we explore several ways of measuring the density field, including Cloud-In-Cell smoothing, adaptive smoothing, and the (scale-independent) Delaunay tessellation, and we use both a Fourier-space and a geometrical tessellation approach to measuring the divergence. We find that the relation between the divergence of the displacement field and the density is significantly tighter and straighter with a logarithmic density variable, especially at low redshifts and for very small ({approx}2 h{sup -1} Mpc) smoothing scales. We find that the grid-based methods are more reliable than the tessellation-based method of calculating both the density and the divergence fields, though inmore » both cases the logarithmic relation works better in the appropriate regime, which corresponds to nonlinear scales for the grid-based methods and low densities for the tessellation-based method.« less
Topological order in matrix Ising models

We study a family of models for an $N_1 \times N_2$ matrix worth of Ising spins $S_{aB}$. In the large $N_i$ limit we show that the spins soften, so that the partition function is described by a bosonic matrix integral with a single `spherical' constraint. In this way we generalize the results of [1] to a wide class of Ising Hamiltonians with $O(N_1,\mathbb{Z})\times O(N_2,\mathbb{Z})$ symmetry. The models can undergo topological large $N$ phase transitions in which the thermal expectation value of the distribution of singular values of the matrix $S_{aB}$ becomes disconnected. This topological transition competes with low temperature glassy and magnetically ordered phases.
Development of a general-purpose machine-learning interatomic potential for aluminum by the physically informed neural network method

Interatomic potentials are the key components of large-scale atomistic simulations of materials. The recently proposed physically-informed neural network (PINN) method combines a high-dimensional regression implemented by an artificial neural network with a physics-based bond-order interatomic potential. Here, the authors develop a highly accurate and transferable PINN potential that reproduces a broad spectrum of physical properties of Al, ranging from lattice dynamics and defect energies to liquid structure and dynamic and the solid-liquid interface tension. The potential enables atomistic simulations of Al with nearly first-principles accuracy while being orders of magnitudes faster.
The distribution of mass and light in cluster infall regions

The CAIRNS (Cluster And Infall Region Nearby Survey) project is a large spectroscopic survey of the infall regions surrounding nine nearby rich clusters of galaxies. I describe the survey and use the kinematics of galaxies in the infall regions to estimate the cluster mass profiles. At small radii, these mass profiles are consistent with independent mass estimates from X-ray observations and Jeans analysis. I demonstrate the dependence of mass-to-light ratios on environment by combining these mass profiles with Two-Micron All-Sky Survey (2MASS) photometry. Near-infrared light is more extended than mass in these clusters, suggesting that dense cluster cores are less efficient at forming galaxies and/or more efficient at disrupting them. At large radii, galaxy populations in cluster infall regions closely resemble those in the field. The mass-to-light ratio at these radii should therefore be a good probe of the global mass-to-light ratio. The mass-to-light ratio in the infall region yields a surprisingly low estimate of $\Omega_m \sim 0.1$.
Chimneys, leopard spots and the identities of Basmajian and Bridgeman

We give a simple geometric argument to derive in a common manner orthospectrum identities of Basmajian and Bridgeman. Our method also considerably simplifies the determination of the summands in these identities. For example, for every odd integer n, there is a rational function q_n of degree 2(n − 2) so that if M is a compact hyperbolic manifold of dimension n with totally geodesic boundary S, there is an identity χ(S) = ∑_(i) q_(n)(e^l_i) where the sum is taken over the orthospectrum of M. When n = 3, this has the explicit form ∑_(i) 1/(e^(2l_(i)) − 1) = −χ(S)/4.
Elucidating the Photoresponse of Ultrathin MoS2 Field-Effect Transistors by Scanning Photocurrent Microscopy

The mechanisms underlying the intrinsic photoresponse of few-layer (FL) molybdenum disulfide (MoS2) field-effect transistors are investigated via scanning photocurrent microscopy. We attribute the locally enhanced photocurrent to band-bending-assisted separation of photoexcited carriers at the MoS2/Au interface. The wavelength-dependent photocurrents of FL MoS2 transistors qualitatively follow the optical absorption spectra of MoS2, providing direct evidence of interband photoexcitation. Time and spectrally resolved photocurrent measurements at varying external electric fields and carrier concentrations establish that drift-diffusion currents dominate photothermoelectric currents in devices under bias.
Explicit expressions for the moments of the size of an (s,s + 1)-core partition with distinct parts

Abstract For fixed s, the size of an ( s , s + 1 ) -core partition with distinct parts can be seen as a random variable X s . Using computer-assisted methods, we derive formulas for the expectation, variance, and higher moments of X s in terms of s. Our results give good evidence that X s is asymptotically normal.
Hilbert space renormalization for the many-electron problem

Renormalization is a powerful concept in the many-body problem. Inspired by the highly successful density matrix renormalization group (DMRG) algorithm, and the quantum chemical graphical representation of configuration space, we introduce a new theoretical tool: Hilbert space renormalization, to describe many-electron correlations. While in DMRG, the many-body states in nested Fock subspaces are successively renormalized, in Hilbert space renormalization, many-body states in nested Hilbert subspaces undergo renormalization. This provides a new way to classify and combine configurations. The underlying wavefunction Ansatz, namely, the Hilbert space matrix product state (HS-MPS), has a very rich and flexible mathematical structure. It provides low-rank tensor approximations to any configuration interaction (CI) space through restricting either the “physical indices” or the coupling rules in the HS-MPS. Alternatively, simply truncating the “virtual dimension” of the HS-MPS leads to a family of size-extensive wave function Ansatze that can be used efficiently in variational calculations. We make formal and numerical comparisons between the HS-MPS, the traditional Fock-space MPS used in DMRG, and traditional CI approximations. The analysis and results shed light on fundamental aspects of the efficient representation of many-electron wavefunctions through the renormalization of many-body states.
A heat kernel proof of the index theorem for deformation quantization

We give a heat kernel proof of the algebraic index theorem for deformation quantization with separation of variables on a pseudo-Kahler manifold. We use normalizations of the canonical trace density of a star product and of the characteristic classes involved in the index formula for which this formula contains no extra constant factors.
The Quest for High Critical Current in Applied High-Temperature Superconductors

We present a perspective on a new critical-current-by-design paradigm to tailor and enhance the current-carrying capacity of applied superconductors. Critical-current-by-design is based on large-scale simulations of vortex matter pinning in high-temperature superconductors and has qualitative and quantitative predictive powers to elucidate vortex dynamics under realistic conditions and to propose vortex pinning defects that could enhance the critical current, particularly at high magnetic fields. The simulations are validated with controlled experiments and demonstrate a powerful tool for designing high-performance superconductors for targeted applications.
Hydrodynamic Torques in Circumbinary Accretion Disks

Gaseous disks have been proposed as a mechanism for facilitating mergers of binary black holes. We explore circumbinary disk systems to determine the evolution of the central binary. To do so, we perform 3D, hydrodynamic, locally isothermal simulations of circumbinary disks on a Cartesian grid. We focus on binaries of equal mass ratios on fixed circular orbits. To investigate the orbital evolution of the binary, we examine the various torques exerted on the system. For the case where the disk plane and binary orbital plane are aligned, we find that the total torque is positive so that the semi-major axis of the binary increases. For the misaligned case, we run simulations with the binary orbital plane and disk midplane misaligned by 45\degree and find the same results - the binary grows. The timescale for the circumbinary disk to realign to the plane of the binary is consistent with the global viscous timescale of the disk.
The minimal SUSY B − L model: simultaneous Wilson lines and string thresholds

In previous work, we presented a statistical scan over the soft supersymmetry breaking parameters of the minimal SUSY B − L model. For specificity of calculation, unification of the gauge parameters was enforced by allowing the two $$ {\mathbb{Z}}_3\times {\mathbb{Z}}_3 $$ Wilson lines to have mass scales separated by approximately an order of magnitude. This introduced an additional “left-right” sector below the unification scale. In this paper, for three important reasons, we modify our previous analysis by demanding that the mass scales of the two Wilson lines be simultaneous and equal to an “average unification” mass 〈M U 〉. The present analysis is 1) more “natural” than the previous calculations, which were only valid in a very specific region of the Calabi-Yau moduli space, 2) the theory is conceptually simpler in that the left-right sector has been removed and 3) in the present analysis the lack of gauge unification is due to threshold effects — particularly heavy string thresholds, which we calculate statistically in detail. As in our previous work, the theory is renormalization group evolved from 〈M U 〉 to the electroweak scale — being subjected, sequentially, to the requirement of radiative B − L and electroweak symmetry breaking, the present experimental lower bounds on the B − L vector boson and sparticle masses, as well as the lightest neutral Higgs mass of ∼125 GeV. The subspace of soft supersymmetry breaking masses that satisfies all such constraints is presented and shown to be substantial.
Advances in modeling of scanning charged-particle-microscopy images

Modeling artificial scanning electron microscope (SEM) and scanning ion microscope images has recently become important. This is because of the need to provide repeatable images with a priori determined parameters. Modeled artificial images are highly useful in the evaluation of new imaging and metrological techniques, like image-sharpness calculation, or drift-corrected image composition (DCIC). Originally, the NIST-developed artificial image generator was designed only to produce the SEM images of gold-on-carbon resolution sample for image-sharpness evaluation. Since then, the new improved version of the software was written in C++ programming language and is in the Public Domain. The current version of the software can generate arbitrary samples, any drift function, and many other features. This work describes scanning in charged-particle microscopes, which is applied both in the artificial image generator and the DCIC technique. As an example, the performance of the DCIC technique is demonstrated.
Symmetries of analytic curves

Abstract Analytic curves are classified w.r.t. their symmetry under a given regular and separately analytic Lie group action G × M → M on an analytic manifold. We show that a non-constant analytic curve γ : D → M is either free or exponential – i.e., up to analytic reparametrization of the form t ↦ exp ⁡ ( t ⋅ g → ) ⋅ x . The vector g → ∈ g is additionally proven to be unique up to (non-zero scalation and) addition of elements in the Lie algebra of the stabilizer G γ ≡ { g ∈ G | g ⋅ γ = γ } of the curve γ. We furthermore prove that in the free case, γ splits into countably many immersive subcurves – each of them discretely generated by G. This means that each such subcurve δ : D ⊇ ( ι ′ , ι ) → M is build up countably many G-translates of a symmetry free building block δ | Δ , whereby three different cases can occur: − In the shift case, the building blocks are continuously distributed in δ, with Δ always compact. Then, δ is created by iterated shifts of δ | Δ by some g ∈ G and its inverse; whereby the class [ e ] ≠ [ g ] ∈ G / G γ is uniquely determined, as well as the same for each possible decomposition. − In the flip case, there exist countably many building blocks – each of them defined on a compact interval, and contained in the one and only decomposition that exists in this case. Here, δ is created by iterated flips at the boundary points of these building blocks, whereby the occurring transformations are generated by two non-trivial classes in G / G γ . − In the mirror case, there exists exactly one symmetry (flipping) point δ ( τ ) , as well as one translation class [ e ] ≠ [ g ] ∈ G / G γ . The one and only decomposition of δ is thus given by δ | ( i ′ , τ ] , δ | [ τ , i ) , whereby δ | ( i ′ , τ ] is flipped into δ | [ τ , i ) or vice versa (or both). We finally extend the classification result to the analytic 1-submanifold case. Specifically, we show that an analytic 1-submanifold of M is either free or (exponential, i.e.) analytically diffeomorphic to U ( 1 ) or to an interval via the exponential map. The corresponding decomposition results in the free case are outlined in this paper, but proven in a separate one.
Dynamics and memory of boundary stresses in discontinuous shear thickening suspensions during oscillatory shear.

We report direct measurements of spatially resolved surface stresses of a dense suspension during large amplitude oscillatory shear (LAOS) in the discontinuous shear thickening regime using boundary stress microscopy. Consistent with previous studies, bulk rheology shows a dramatic increase in the complex viscosity above a frequency-dependent critical strain. We find that the viscosity increase is coincident with that appearance of large heterogeneous boundary stresses, indicative of the formation of transient solid-like phases (SLPs) on spatial scales large compared to the particle size. The critical strain for the appearance of SLPs is largely determined by the peak oscillatory stress, which depends on the peak shear rate and the frequency-dependent suspension viscosity. The SLPs dissipate and reform on each cycle, with a spatial pattern that is highly variable at low frequencies but remarkably persistent at the highest frequency measured (ω = 10 rad s−1).
A route to improving RPA excitation energies through its connection to equation-of-motion coupled cluster theory

We revisit the connection between equation-of-motion coupled cluster (EOM-CC) and random phase approximation (RPA) explored recently by Berkelbach [J. Chem. Phys. 149, 041103 (2018)] and unify various methodological aspects of these diverse treatments of ground and excited states. The identity of RPA and EOM-CC based on the ring coupled cluster doubles is established with numerical results, which was proved previously on theoretical grounds. We then introduce new approximations in EOM-CC and RPA family of methods, assess their numerical performance, and explore a way to reap the benefits of such a connection to improve on excitation energies. Our results suggest that addition of perturbative corrections to account for double excitations and missing exchange effects could result in significantly improved estimates.
Inflating Topic Relevance with Ideology: A Case Study of Political Ideology Bias in Social Topic Detection Models

We investigate the impact of political ideology biases in training data. Through a set of comparison studies, we examine the propagation of biases in several widely-used NLP models and its effect on the overall retrieval accuracy. Our work highlights the susceptibility of large, complex models to propagating the biases from human-selected input, which may lead to a deterioration of retrieval accuracy, and the importance of controlling for these biases. Finally, as a way to mitigate the bias, we propose to learn a text representation that is invariant to political ideology while still judging topic relevance.
Geometric and control optimization of a two cross-flow turbine array

Cross-flow turbines, also known as vertical-axis turbines, convert the kinetic energy in moving fluid to mechanical energy using blades that rotate about an axis perpendicular to the incoming flow. In this work, the performance of a two-turbine array in a recirculating water channel was experimentally optimized across 64 unique array configurations. For each configuration, turbine performance was optimized using tip-speed ratio control, where the rotation rate for each turbine is optimized individually, and using coordinated control, where the turbines are optimized to operate at synchronous rotation rates but with a phase difference. For each configuration and control strategy, the consequences of co- and counter-rotations were also evaluated. This is the first experimental cross-flow turbine array study to simultaneously address array geometry, control, and turbine rotation direction. Based on these results, we hypothesize how array configurations and control cases influence interactions between turbines and affect the performance of the array.
Teaching Problem-Solving and Preventive Law Skills through International Labour and Employment Law

This essay describes how problem-solving and preventive law principles apply in the teaching of international labor and employment law. This is because the subject itself crosses disciplinary and geographical boundaries. Students are taught about the importance of the lawyer's role as a counselor, rather than simply a litigator, which is at the center of the model of the lawyer as a problem solver.
Questioning Hierarchies of Harm: Women, Forced Migration, and International Criminal Law

Though international criminal law has made great strides in addressing harm perpetrated against women in wartime, its gendered structure diverts attention away from other significant harms that women endure as a result of armed conflict. In particular, international criminal law's hierarchy of harm elevates crimes committed as part of a plan or pattern across political groups over equally serious forms of harm perpetrated randomly, often within political groups. Thus the private and opportunistic harms enabled by situations of displacement and perpetrated against female forced migrants do not fall clearly within the framework of international criminal law. This vacuum of accountability extends beyond international criminal law, as female forced migrants cannot rely on their own governments, their host governments, and often even international humanitarian organisations to protect them against opportunistic violence. International criminal law could fill the void only after quite serious reconstruction, namely expansion of its scope and restructuring of its focus. It may be that a structure designed specifically to prevent and account for opportunistic violence against female forced migrants would be better equipped to perform that task. Criminal accountability might be better performed in national legal systems or informal justice systems created within camp environments. There are also solutions other than criminal accountability, such as human rights law, that might be more appropriate in addressing such harms. In the meantime, until a solution is found that places these 'private' crimes on equal footing with 'public' attacks currently prohibited by international criminal law, the serious and frequent harms suffered by forcibly displaced women will continue to be overlooked, relegated to the bottom of the hierarchy of harm.
Judge Not: In Defense of Minority-Culture Arbitration

Arbitration can serve as a necessary safe harbor from procedural and substantive cultural bias in the general public courts. Arbitration also can serve as a laboratory for process reforms as cultural minorities attempt to craft rules that better govern their lives than do the purportedly “one size fits all” rules that the majority has crafted. In so allowing cultural minorities to structure their lives and legal disputes in ways that reflect their particular needs, minority-culture arbitration also has great potential for habituating the general public to the realities of the lives of cultural minorities and to the notion that custom-made responses to these realities are both possible and appropriate. These two habituations would be likely to lead to easier acceptance of necessary process reforms that would better serve cultural minorities in the public courts.Each time cultural minorities use arbitration to contract around a hostile or dysfunctional rule of general application and to replace this rule with a better-serving custom-made rule, they have an opportunity to demonstrate to the general public that the process shortcomings that drove the cultural minorities from the general public courts are not intractable. They also have the opportunity to demonstrate to the general public the utility of custom-made solutions to minority-culture concerns and that these solutions to process shortcomings can be implemented with little cost to the general public. If minority-culture arbitration were to become routine, it is possible that the general public would habituate to the idea that process-customization is both practical and useful. Such habituation would lessen resistance to adoption of process reforms tailored to cultural minorities.Arbitration also can facilitate habituation in a larger social context. This second tier of habituation arises from the consequence that arbitration allows the minority culture to survive and even to flourish. Biased procedural and substantive law undermines the minority culture at the same time that it disadvantages the minority-culture litigant. Arbitration allows cultural minorities to protect themselves from these majoritarian procedural and substantive biases that deny the validity of their values and relationships and consequently undermine those values and relationships.The end product of this protective maneuver is a larger public space for the minority culture. As the minority culture flourishes, the general public more frequently comes into contact with that culture and habituates to its realties. Again, this habituation is likely to pave the way for process reforms in the majoritarian legal system.
Impacts of the Uruguay Round on Agricultural Commodity Markets: Implications for Russia

Meyers uses the FAPRI agricultural commodity models to help analyze how the final passage of the GATT agreement will impact Russia, the Newly Independent States (NIS), and Central and Eastern Europe. While there are benefits from the GATT accord, he notes that the GATT agreement cannot be seen as a substitute for the efforts that are needed on developing more efficient production and processing systems, improved marketing infrastructure, and improved quality and diversity of products.
“GUILT BY ASSOCIATION” AND THE POSTWAR CIVIL LIBERTARIANS

In recent years, the constitutional freedom of association has assumed a relatively low profile. Today, the most extended discussions of the right consider it as a second-order countervailing claim in civil rights cases involving questions of identity and the right to exclude. This article provides a brief overview of the right at a time when it was one of the most widely discussed, first-order constitutional rights, and when those discussions centered not on the right to exclude but on the question of “guilt by association.” The article provides a sampling of the way that right was considered in the immediate post-World War Two years in the writings of some of the era's most prominent civil libertarian thinkers – Leo Pfeffer, Milton Konvitz, Robert Cushman, Henry Steele Commager, Zechariah Chafee, Jr., and Sidney Hook. These writings demonstrate that doctrinal development concerning the right was driven by its implication in two of the major political issues of the day: domestic security at the height of the Cold War and civil rights. The article concludes by arguing that, in the aftermath of the September 11 attacks and the ongoing fight against terrorism, free association questions are likely to assume renewed prominence. It argues further that, in a contemporary context, those thinking about the most pressing freedom of association questions would profit by looking less to the more recent discussions of the right as a matter of the right to exclude, and more to the highly-relevant discussions of “guilt by association” by the currently less well known mid-century civil libertarians.