cssi/SciSciGPT-SciSciNet huggingface dataset:
STACCO: Differentially Analyzing Side-Channel Traces for Detecting SSL/TLS Vulnerabilities in Secure Enclaves

Intel Software Guard Extension (SGX) offers software applications a shielded execution environment, dubbed enclave, to protect their confidentiality and integrity from malicious operating systems. As processors with this extended feature become commercially available, many new software applications are developed to enrich to the SGX-enabled ecosystem. One important primitive for these applications is a secure communication channel between the enclave and a remote trusted party. The SSL/TLS protocol, which is the de facto standard for protecting transport-layer network communications, has been broadly regarded a natural choice for such purposes. However, in this paper, we show that the marriage between SGX and SSL may not be smooth sailing. Particularly, we consider a category of side-channel attacks against SSL/TLS implementations in secure enclaves, which we call the control-flow inference attacks. In these attacks, the malicious operating system kernel may perform a powerful man-in-the-kernel attack to collect execution traces of the enclave programs at the page level, the cacheline level, or the branch level, while positioning itself in the middle of the two communicating parties. At the center of our work is a differential analysis framework, dubbed Stacco, to dynamically analyze the SSL/TLS implementations and detect vulnerabilities-discernible execution traces-that can be exploited as decryption oracles. Surprisingly, in spite of the prevailing constant-time programming paradigm adopted by many cryptographic libraries, we found exploitable vulnerabilities in the latest versions of all the SSL/TLS libraries we have examined. To validate the detected vulnerabilities, we developed a man-in-the-kernel adversary to demonstrate Bleichenbacher attacks against the latest OpenSSL library running in the SGX enclave (with the help of Graphene) and completely broke the PreMasterSecret encrypted by a 4096-bit RSA public key with only 57286 queries. We also conducted CBC padding oracle attacks against the latest GnuTLS running in Graphene-SGX and an open-source SGX implementation of mbedTLS (i.e., mbedTLS-SGX) that runs directly inside the enclave, and showed that it only needs 48388 and 25717 queries, respectively, to break one block of AES ciphertext. Empirical evaluation suggests these man-in-the-kernel attacks can be completed within 1 or 2 hours. Our results reveal the insufficient understanding of side-channel security in SGX settings, and our study will provoke discussions on the secure implementation and adoption of SSL/TLS in secure enclaves.
Ruelle zeta function at zero for surfaces

We show that the Ruelle zeta function for a negatively curved oriented surface vanishes at zero to the order given by the absolute value of the Euler characteristic. This result was previously known only in constant curvature.
EFFECTS OF DUST FEEDBACK ON VORTICES IN PROTOPLANETARY DISKS

We carried out two-dimensional, high-resolution simulations to study the effect of dust feedback on the evolution of vortices induced by massive planets in protoplanetary disks. Various initial dust to gas disk surface density ratios (0.001-0.01) and dust particle sizes (Stokes number 4 × 10–4-0.16) are considered. We found that while dust particles migrate inward, vortices are very effective at collecting them. When dust density becomes comparable to gas density within the vortex, a dynamical instability is excited and it alters the coherent vorticity pattern and destroys the vortex. This dust feedback effect is stronger with a higher initial dust/gas density ratio and larger dust grain. Consequently, we found that the disk vortex lifetime can be reduced up to a factor of 10. We discuss the implications of our findings on the survivability of vortices in protoplanetary disks and planet formation.
Cyclic surgery, degrees of maps of character curves, and volume rigidity for hyperbolic manifolds

This paper proves a theorem about Dehn surgery using a new theorem about PSL2C character varieties. Confirming a conjecture of Boyer and Zhang, this p aper shows that a small hyperbolic knot in a homotopy sphere having a non-trivial cyclic slope r has an incompressible surface with non-integer boundary slope strictly between r − 1 and r + 1. A corollary is that any small knot which has only integer boundary slopes has Property P. The proof uses connections between the topology of the complement of the knot, M, and the PSL2C character variety of M that were discovered by Culler and Shalen. The key lemma, which should be of independent interest, is that for certain components of the character variety of M, the map on character varieties induced by ∂M → M is a birational isomorphism onto its image. This in turn depends on a fancy version of Mostow rigidity due to Gromov, Thurston, and Goldman. The proof of the theorem about Dehn surgery also gives information about the diameter of the set of boundary slopes of M. Let me start with the theorem about Dehn surgery. Let K be a knot in a compact, closed, 3manifold Σ, that is, a tame embedding S 1 → Σ. The complement of K, M, is Σ minus an open regular neighborhood of K. So M is a compact 3-manifold whose boundary is a torus. Suppose γ is a simple closed curve in ∂M. We can create a closed manifold Mγ from M by taking a solid torus and gluing its boundary to ∂M in such a way that γ bounds a disc in the solid torus (Mγ depends only on the isotopy class of γ). The new manifold Mγ is called a Dehn filling of M or a Dehn surgeryon K. Recently, many people have studied what kinds of manifolds arise when you
Theoretical higgs mass bounds in the standard model and supersymmetric extensions

Abstract These lectures provide a very basic introduction to different theoretical limits on the mass of Higgs scalars. Particular attention is devoted to the pure Standard Model and its Minimal Supersymmetric extension (MSSM).
Millikelvin-compatible apparatus for studies of quantum materials under uniaxial stress

Various new phenomena emerge in quantum materials under elastic deformations, such as hydrostatic or uniaxial stresses. In particular, using uniaxial strain or stress can help to tune or uncover specific structural or electronic orders in materials with multiple coexisting phases. Those phases may be associated with a quantum phase transition requiring a millikelvin environment combined with multiple experimental probes. Here, we describe our unique apparatus, which allows in situ tuning of strain in large samples inside a dilution refrigerator while the samples are monitored via an optical microscope. We describe the engineering details and show some typical results of characterizing superconducting strontium titanate under stress. This letter should serve as a practical reference for experts in ultra-low temperature experimental physics involving uniaxial stresses or strains.
The sharp for the Chang model is small

Woodin has shown that if there is a measurable Woodin cardinal then there is, in an appropriate sense, a sharp for the Chang model. We produce, in a weaker sense, a sharp for the Chang model using only the existence of a cardinal $$\kappa $$ having an extender of length $$\kappa ^{+\omega _1}$$ .
Quasi-periodicity of Supermassive Binary Black Hole Accretion Approaching Merger

In this paper we continue the first ever study of magnetized mini-disks coupled to circumbinary accretion in a supermassive binary black hole (SMBBH) approaching merger reported in Bowen et al. We extend this simulation from 3 to 12 binary orbital periods. We find that relativistic SMBBH accretion acts as a resonant cavity, where quasi-periodic oscillations tied to the frequency at which the black hole’s (BH’s) orbital phase matches a nonlinear m = 1 density feature, or “lump,” in the circumbinary accretion disk permeate the system. The rate of mass accretion onto each of the mini-disks around the BHs is modulated at the beat frequency between the binary frequency and the lump’s mean orbital frequency, i.e., , while the total mass accretion rate of this equal-mass binary is modulated at two different frequencies, and . The instantaneous rotation rate of the lump itself is also modulated at two frequencies close to the modulation frequencies of the total accretion rate, and . Because of the compact nature of the mini-disks in SMBBHs approaching merger, the inflow times within the mini-disks are comparable to the period on which their mass supply varies, so that their masses—and the accretion rates they supply to their BHs—are strongly modulated at the same frequency. In essence, the azimuthal symmetry of the circumbinary disk is broken by the dynamics of orbits near a binary, and this m = 1 asymmetry then drives quasi-periodic variation throughout the system, including both accretion and disk-feeding. In SMBBHs approaching merger, such time variability could introduce distinctive, increasingly rapid, fluctuations in their electromagnetic emission.
Optimal designs for mixed models in experiments based on ordered units

We consider experiments for comparing treatments using units that are ordered linearly over time or space within blocks. In addition to the block effect, we assume that a trend effect influences the response. The latter is modeled as a smooth component plus a random term that captures departures from the smooth trend. The model is flexible enough to cover a variety of situations; for instance, most of the effects may be either random or fixed. The information matrix for a design will be a function of several variance parameters. While data will shed light on the values of these parameters, at the design stage, they are unlikely to be known, so we suggest a maximin approach, in which a minimal information matrix is maximized. We derive maximin universally optimal designs and study their robustness. These designs are based on semibalanced arrays. Special cases correspond to results available in the literature.
ORIGIN OF THE GALAXY MASS-METALLICITY-STAR FORMATION RELATION

We describe an equilibrium model that links the metallicity of low-redshift galaxies to stellar evolution models. It enables the testing of different stellar initial mass functions and metal yields against observed galaxy metallicities. We show that the metallicities of more than 80,000 Sloan Digital Sky Survey galaxies in the low-redshift range 0.07 ≤ z ≤ 0.3 considerably constrain stellar evolution models that simultaneously relate galaxy stellar mass, metallicity, and star formation rates to the infall rate of low-metallicity extragalactic gas and outflow of enriched matter. A feature of our model is that it encompasses both the active star forming phases of a galaxy and epochs during which the same galaxy may lie fallow. We show that the galaxy mass-metallicity-star formation relation can be traced to infall of extragalactic gas mixing with native gas from host galaxies to form stars of observed metallicities, the most massive of which eject oxygen into extragalactic space. Most consequential among our findings is that, on average, extragalactic infall accounts for one half of the gas required for star formation, a ratio that is remarkably constant across galaxies with stellar masses ranging at least from M* = 2 × 10{sup 9} to 6 × 10{sup 10}more » M {sub ☉}. This leads us to propose that star formation is initiated when extragalactic infall roughly doubles the mass of marginally stable interstellar clouds. The processes described may also account quantitatively for the metallicity of extragalactic space, though to check this the fraction of extragalactic baryons will need to be more firmly established.« less
Field enhancement in plasmonic nanostructures

Efficient generation of charge carriers from a metallic surface is a critical challenge in a wide variety of applications including vacuum microelectronics and photo-electrochemical devices. Replacing semiconductors with vacuum/gas as the medium of electron transport offers superior speed, power, and robustness to radiation and temperature. We propose a metallic resonant surface combining optical and electrical excitations of electrons and significantly reducing powers required using plasmon-induced enhancement of confined electric field. The properties of the device are modeled using the exact solution of the time-dependent Schrodinger equation at the barrier. Measurement results exhibit strong agreement with an analytical solution, and allow us to extract the field enhancement factor at the surface. Significant photocurrents are observed using combination of optical power and 10 V DC excitation on the surface. The model suggests optical field enhancement of 3 orders of magnitude at the metal interface due to plasmonic resonance. This simple planar structure provides valuable evidence on the electron emission mechanisms involved and it can be used for implementation of semiconductor compatible vacuum devices.
Quantum Fourier transform revisited

Author(s): Camps, D; Van Beeumen, R; Yang, C | Abstract: The fast Fourier transform (FFT) is one of the most successful numerical algorithms of the 20th century and has found numerous applications in many branches of computational science and engineering. The FFT algorithm can be derived from a particular matrix decomposition of the discrete Fourier transform (DFT) matrix. In this paper, we show that the quantum Fourier transform (QFT) can be derived by further decomposing the diagonal factors of the FFT matrix decomposition into products of matrices with Kronecker product structure. We analyze the implication of this Kronecker product structure on the discrete Fourier transform of rank-1 tensors on a classical computer. We also explain why such a structure can take advantage of an important quantum computer feature that enables the QFT algorithm to attain an exponential speedup on a quantum computer over the FFT algorithm on a classical computer. Further, the connection between the matrix decomposition of the DFT matrix and a quantum circuit is made. We also discuss a natural extension of a radix-2 QFT decomposition to a radix-d QFT decomposition. No prior knowledge of quantum computing is required to understand what is presented in this paper. Yet, we believe this paper may help readers to gain some rudimentary understanding of the nature of quantum computing from a matrix computation point of view.
Transverse string topology and the cord algebra

We define a coalgebra structure for open strings transverse to any framed codimension 2 submanifold. When the submanifold is a knot in R^3, we show this structure recovers a specialization of the Ng cord algebra, a non-trivial knot invariant which is not determined by a number of other knot invariants.
Autonomous Tissue Manipulation via Surgical Robot Using Learning Based Model Predictive Control

Tissue manipulation is a frequently used fundamental subtask of any surgical procedures, and in some cases it may require the involvement of a surgeon’s assistant. The complex dynamics of soft tissue as an unstructured environment is one of the main challenges in any attempt to automate the manipulation of it via a surgical robotic system. Two AI learning based model predictive control algorithms using vision strategies are proposed and studied: (1) reinforcement learning and (2) learning from demonstration. Comparison of the performance of these AI algorithms in a simulation setting indicated that the learning from demonstration algorithm can boost the learning policy by initializing the predicted dynamics with given demonstrations. Furthermore, the learning from demonstration algorithm is implemented on a Raven IV surgical robotic system and successfully demonstrated feasibility of the proposed algorithm using an experimental approach. This study is part of a profound vision in which the role of a surgeon will be redefined as a pure decision maker whereas the vast majority of the manipulation will be conducted autonomously by a surgical robotic system. A supplementary video can be found at: http://bionics.seas.ucla.edu/research/surgeryproject17.html
On the regularity of maximal operators

We study the regularity of the bilinear maximal operator when applied to Sobolev functions, proving that it maps W 1,p (R) × W 1,q (R) → W 1,r (R) with 1 1. We also investigate the almost everywhere and weak convergence under the action of the classical Hardy-Littlewood maximal operator, both in its global and local versions.
Geometry of Deligne cohomology

It is well known that degree two Deligne cohomology groups can be identified with groups of isomorphism classes of holomorphic line bundles with connections. There is also a geometric description of degree three Deligne cohomology, due to J-L. Brylinski and P. Deligne, in terms of gerbes with connective structures and curvings. This paper gives a geometric interpretation of Deligne cohomology of all degrees, in terms of equivalence classes of higher line bundles with $k$-connections. It is also shown that the classical Abel-Jacobi isomorphism $Pic^0(X) \cong J(X)$ generalizes to the isomorphism between groups of equivalence classes of topologically trivial 1-holomorphic higher line bundles with $k$-connections and Griffiths intermediate Jacobians.
PSEUDO-NEWTONIAN POTENTIALS FOR NEARLY PARABOLIC ORBITS

We describe a pseudo-Newtonian potential which, to within 1% error at all angular momenta, reproduces the precession due to general relativity of particles whose specific orbital energy is small compared to c^2 in the Schwarzschild metric. For bound orbits, the constraint of low energy is equivalent to requiring the apoapsis of a particle to be large compared to the Schwarzschild radius. Such low-energy orbits are ubiquitous close to supermassive black holes in galactic nuclei, but the potential is relevant in any context containing particles on low-energy orbits. Like the more complex post-Newtonian expressions, the potential correctly reproduces the precession in the far field, but also correctly reproduces the position and magnitude of the logarithmic divergence in precession for low angular momentum orbits. An additional advantage lies in its simplicity, both in computation and implementation. We also provide two simpler, but less accurate potentials, for cases where orbits always remain at large angular momenta, or when the extra accuracy is not needed. In all of the presented cases, the accuracy in precession in low-energy orbits exceeds that of the well-known potential of Paczynski & Wiita, which has ~30% error in the precession at all angular momenta.
(Non)-renormalization of the chiral vortical effect coefficient

We show using diagramtic arguments that in some (but not all) cases, the temperature dependent part of the chiral vortical effect coefficient is independent of the coupling constant. An interpretation of this result in terms of quantization in the effective 3 dimensional Chern-Simons theory is also given. In the language of 3D, dimensionally reduced theory, the value of the chiral vortical coefficient is related to the formula ∑ = 1 ∞ n = − 1/12 . We also show that in the presence of dynamical gauge fields, the CVE coefficient is not protected from renormalization, even in the large N limit.
An Attempt to Detect the Galactic Bulge at 12 Microns with IRAS

Surface brightness maps at 12 μm, derived from observations with the Infrared Astronomical Satellite (IRAS), are used to estimate the integrated flux as a function of Galactic latitude along the minor axis from the Galactic bulge at this wavelength. A simple model was used to remove Galactic disk emission (e.g., unresolved stars and dust) from the IRAS measurements. The resulting estimates are compared with predictions for the 12 μm bulge surface brightness based on observations of complete samples of optically identified M giants in several minor-axis bulge fields. No evidence is found for any significant component of 12 μm emission in the bulge other than that expected from the optically identified M star sample plus normal, lower luminosity stars. Known large-amplitude variables and point sources from the IRAS catalog contribute only a small fraction to the total 12 μm flux.
The decategorification of bordered Heegaard Floer homology

Bordered Heegaard Floer homology is an invariant for 3-manifolds, which associates to a surface F an algebra A(Z), and to a 3-manifold Y with boundary, together with an orientation-preserving diffeomorphism \phi from F to \bdy Y, a module over A(Z). We study the Grothendieck group of modules over A(Z), and define an invariant lying in this group for every bordered 3-manifold. We prove that this invariant recovers the kernel of the inclusion of H_1(\bdy Y; Z) into H_1(Y; Z) if H_1(Y, \bdy Y; Z) is finite, and is 0 otherwise. We also study the properties of this invariant corresponding to gluing. As one application, we show that the pairing theorem for bordered Floer homology categorifies the classical Alexander polynomial formula for satellites.
Point group symmetry and deformation-induced symmetry breaking of superlattice materials

The point group symmetry of materials is closely related to their physical properties and quite important for material modelling. However, superlattice materials have more complex symmetry conditions than crystals due to their multi-level structural feature. Thus, a theoretical framework is proposed to characterize and determine the point group symmetry of non-magnetic superlattice materials systematically. A variety of examples are presented to show the symmetry features of superlattice materials in different dimensions and scales. In addition, the deformation-induced symmetry-breaking phenomenon is also studied for superlattice materials, which has potential application in tuning physical properties by imposing a strain field.
Evaluating and Characterizing Human Rationales

Two main approaches for evaluating the quality of machine-generated rationales are: 1) using human rationales as a gold standard; and 2) automated metrics based on how rationales affect model behavior. An open question, however, is how human rationales fare with these automatic metrics. Analyzing a variety of datasets and models, we find that human rationales do not necessarily perform well on these metrics. To unpack this finding, we propose improved metrics to account for model-dependent baseline performance. We then propose two methods to further characterize rationale quality, one based on model retraining and one on using ``fidelity curves'' to reveal properties such as irrelevance and redundancy. Our work leads to actionable suggestions for evaluating and characterizing rationales.
Analog Noise Reduction in Enzymatic Logic Gates

In this work, we demonstrate both experimentally and theoretically that the analog noise generation by a single enzymatic logic gate can be dramatically reduced to yield gate operation with virtually no input noise amplification. We demonstrate that when a cosubstrate with a much smaller affinity than the primary substrate is used, a negligible increase in the noise output from the logic gate is obtained, as compared to the input noise level. Our general theoretical conclusions were confirmed by experimental realizations of the AND logic gate based on the enzyme horseradish peroxidase using hydrogen peroxide as the substrate, with 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) or ferrocyanide as cosubstrates with vastly different rate constants.
Twisted six dimensional gauge theories on tori, matrix models, and integrable systems

We use the Dijkgraaf-Vafa technique to study massive vacua of 6D SU(N) SYM theories on tori with R-symmetry twists. One finds a matrix model living on the compactification torus with a genus 2 spectral curve. The jacobian of this curve is closely related to a twisted four torus T in which the Seiberg-Witten curves of the theory are embedded. We also analyze R-symmetry twists in a bundle with nontrivial first Chern class which yields intrinsically 6D SUSY breaking and a novel matrix integral whose eigenvalues float in a sea of background charge. Next we analyze the underlying integrable system of the theory, whose phase space we show to be a system of N−1 points on T. We write down an explicit set of Poisson commuting hamiltonians for this system for arbitrary N and use them to prove that equilibrium configurations with respect to all hamiltonians correspond to points in moduli space where the Seiberg-Witten curve maximally degenerates to genus 2, thereby recovering the matrix model spectral curve. We also write down a conjecture for a dual set of Poisson commuting variables which could shed light on a particle-like interpretation of the system.
How hidden are hidden processes? A primer on crypticity and entropy convergence.

We investigate a stationary process’s crypticity—a measure of the difference between its hidden state information and its observed information—using the causal states of computational mechanics. Here, we motivate crypticity and cryptic order as physically meaningful quantities that monitor how hidden a hidden process is. This is done by recasting previous results on the convergence of block entropy and block-state entropy in a geometric setting, one that is more intuitive and that leads to a number of new results. For example, we connect crypticity to how an observer synchronizes to a process. We show that the block-causal-state entropy is a convex function of block length. We give a complete analysis of spin chains. We present a classification scheme that surveys stationary processes in terms of their possible cryptic and Markov orders. We illustrate related entropy convergence behaviors using a new form of foliated information diagram. Finally, along the way, we provide a variety of interpretations of crypticity and cryptic order to establish their naturalness and pervasiveness. This is also a first step in developing applications in spatially extended and network dynamical systems.
Spin(7)-Instantons, Cayley Submanifolds and Fueter Sections

We prove an existence theorem for Spin(7)-instantons, which are highly concentrated near a Cayley submanifold; thus giving a partial converse to Tian’s foundational compactness theorem (Ann Math (2) 151(1):193–268, 2000). As an application, we show how to construct Spin(7)-instantons on Spin(7)-manifolds with suitable local K3 Cayley fibrations. This recovers an example constructed by Lewis (Spin(7) instantons, Ph.D. Thesis, 1998).
The Cayley plane and string bordism

This paper shows that, away from 6, the kernel of the Witten genus is precisely the ideal consisting of (bordism classes of) Cayley plane bundles with connected structure group, but only after restricting the Witten genus to string bordism. It does so by showing that the divisibility properties of Cayley plane bundle characteristic numbers arising in Borel‐Hirzebruch Lie group-theoretic calculations correspond precisely to the divisibility properties arising in the Hovey‐Ravenel‐Wilson BP Hopf ring-theoretic calculation of string bordism at primes greater than 3. 57R90, 58J26
SIMPLE MODELS OF METAL-LINE ABSORPTION AND EMISSION FROM COOL GAS OUTFLOWS

We analyze the absorption and emission-line profiles produced by a set of simple, cool gas wind models motivated by galactic-scale outflow observations. We implement Monte Carlo radiative transfer techniques that track the propagation of scattered and fluorescent photons to generate one-dimensional spectra and two-dimensional spectral images. We focus on the Mg II {lambda}{lambda}2796, 2803 doublet and Fe II UV1 multiplet at {lambda} {approx} 2600 A, but the results are applicable to other transitions that trace outflows (e.g., Na I, H I Ly{alpha}, Si II). By design, the resonance transitions show blueshifted absorption but one also predicts strong resonance and fine-structure line emission at roughly the systemic velocity. This line-emission 'fills in' the absorption, reducing the equivalent width by up to 50%, shifting the absorption-line centroid by tens of km s{sup -1}, and reducing the effective opacity near systemic. Analysis of cool gas outflows that ignores this line emission may incorrectly infer that the gas is partially covered, measure a significantly lower peak optical depth, and/or conclude that gas at systemic velocity is absent (e.g., an interstellar or slowly infalling component). Because the Fe II lines are connected by optically thin transitions to fine-structure levels, their profiles more closely reproduce themore » intrinsic opacity of the wind. Together these results naturally explain the absorption and emission-line characteristics observed for star-forming galaxies at z < 1. We also study a scenario promoted to describe the outflows of z {approx} 3 Lyman break galaxies and find profiles inconsistent with the observations due to scattered photon emission. Although line emission complicates the analysis of absorption-line profiles, the surface brightness profiles offer a unique means of assessing the morphology and size of galactic-scale winds. Furthermore, the kinematics and line ratios offer powerful diagnostics of outflows, motivating deep, spatially extended spectroscopic observations.« less
Control of Charging of Electric Vehicles Through Menu-Based Pricing

We propose an online pricing mechanism for electric vehicle (EV) charging. A charging station decides prices for each arriving EV depending on the energy and the time within which the EV will be served (i.e., deadline). The user selects either one of the contracts by paying the prescribed price or rejects all depending on their surpluses. The charging station can serve users using renewable energy and conventional energy. Users may select longer deadlines as they may have to pay less because of the less amount of conventional energy, however, they have to wait a longer period. We consider a myopic charging station and show that there exists a pricing mechanism which jointly maximizes the social welfare and the profit of the charging station when the charging station knows the utilities of the users. However, when the charging station does not know the utilities of the users, the social welfare pricing strategy may not maximize the expected profit of the charging station and even the profit may be 0. We propose a fixed profit pricing strategy which provides a guaranteed fixed profit to the charging station and can maximize the profit in practice. We empirically show that our proposed mechanism reduces the peak-demand and utilizes the limited charging spots in a charging station efficiently.
Visual Designing and Debugging of Deterministic Finite-State Machines in FSM

This article presents a visualization tool for designing and debugging deterministic finite-state machines in FSM -- a domain specific language for the automata theory classroom. Like other automata visualization tools, users can edit machines and observe their execution, given some input. Unlike other automata visualization tools, the user is not burdened nor distracted with rendering a machine as a graph. Furthermore, emphasis is placed on the design of machines and this article presents a novel design recipe for deterministic finite-state machines. In support of the design process, the visualization tool allows for each state to be associated with an invariant predicate. During machine execution, the visualization tool indicates if the proposed invariant holds or does not hold after each transition. In this manner, students can validate and debug their machines before attempting to prove partial correctness or submitting for grading. In addition, any machine edited with the visualization tool can be rendered as executable code. The interface of the visualization tool along with extended examples of its use are presented.
Signatures of black holes at the LHC

Signatures of black hole events at CERN's Large Hadron Collider are discussed. Event simulations are carried out with the Fortran Monte Carlo generator CATFISH. Inelasticity effects, exact field emissivities, color and charge conservation, corrections to semiclassical black hole evaporation, gravitational energy loss at formation and possibility of a black hole remnant are included in the analysis.
Julia implementation of the Dynamic Distributed Dimensional Data Model

Julia is a new language for writing data analysis programs that are easy to implement and run at high performance. Similarly, the Dynamic Distributed Dimensional Data Model (D4M) aims to clarify data analysis operations while retaining strong performance. D4M accomplishes these goals through a composable, unified data model on associative arrays. In this work, we present an implementation of D4M in Julia and describe how it enables and facilitates data analysis. Several experiments showcase scalable performance in our new Julia version as compared to the original Matlab implementation.
PROBABILISTIC ERROR ANALYSIS FOR INNER PRODUCTS.

Probabilistic models are proposed for bounding the forward error in the numerically computed inner product (dot product, scalar product) between two real $n$-vectors. We derive probabilistic pertur...
Floer cohomology, multiplicity and the log canonical threshold

Let f be a polynomial over the complex numbers with an isolated singularity at 0. We show that the multiplicity and the log canonical threshold of f at 0 are invariants of the link of f viewed as a contact submanifold of the sphere.This is done by first constructing a spectral sequence converging to the fixed-point Floer cohomology of any iterate of the Milnor monodromy map whose E1 page is explicitly described in terms of a log resolution of f. This spectral sequence is a generalization of a formula by A’Campo. By looking at this spectral sequence, we get a purely Floer-theoretic description of the multiplicity and log canonical threshold of f.
Experimental proof for resonant diffusion of normal alkanes in LTL and ZSM-12 zeolites

The intra-crystalline diffusion of normal alkanes in LTL and ZSM-12 zeolite was experimentally studied via gravimetric measurements performed at different temperatures. A periodic dependence of the diffusion coefficient on the number of carbon atoms in alkane was detected, which is an experimental proof for resonant diffusion. The present observations were described on the base of the existing theory of the resonant diffusion and several important parameters of the alkane−zeolite interaction and zeolite vibrations were obtained. In the considered temperature region the diffusion coefficient follows the Arrhenius law with periodic dependences of the preexponential factor and activation energy on the number of carbon atoms in alkanes. A compensation effect of simultaneous increases of the preexponential factor and the activation energy was also established.
Non-localizability of electric coupling and gravitational binding of charged objects

The energy–momentum tensor in general relativity contains only localized contributions to the total energy–momentum. Here, we consider a static, spherically symmetric object consisting of a charged perfect fluid. For this object, the total gravitational mass contains a non-localizable contribution of electric coupling (ordinarily associated with electromagnetic mass). We derive an explicit expression for the total mass which implies that the non-localizable contribution of electric coupling is not bound together by gravity, thus ruling out the existence of objects with pure Lorentz electromagnetic mass in general relativity.
Integer part polynomial correlation sequences

Following an approach presented by Frantzikinakis [Multiple correlation sequences and nilsequences. Invent. Math. 202(2) (2015), 875–892], we prove that any multiple correlation sequence defined by invertible measure preserving actions of commuting transformations with integer part polynomial iterates is the sum of a nilsequence and an error term, which is small in uniform density. As an intermediate result, we show that multiple ergodic averages with iterates given by the integer part of real-valued polynomials converge in the mean. Also, we show that under certain assumptions the limit is zero. A transference principle, communicated to us by M. Wierdl, plays an important role in our arguments by allowing us to deduce results for -actions from results for flows.
Nanostructured complex oxides as a route towards thermal behavior in artificial spin ice systems

Author(s): Chopdekar, RV; Li, B; Wynn, TA; Lee, MS; Jia, Y; Liu, ZQ; Biegalski, MD; Retterer, ST; Young, AT; Scholl, A; Takamura, Y | Abstract: We have used soft x-ray photoemission electron microscopy to image the magnetization of single-domain La0.7Sr0.3MnO3 nanoislands arranged in geometrically frustrated configurations such as square ice and kagome ice geometries. Upon thermal randomization, ensembles of nanoislands with strong interisland magnetic coupling relax towards low-energy configurations. Statistical analysis shows that the likelihood of ensembles falling into low-energy configurations depends strongly on the annealing temperature. Annealing to just below the Curie temperature of the ferromagnetic film (TC=338K) allows for a much greater probability of achieving low-energy configurations as compared to annealing above the Curie temperature. At this thermally active temperature of 325 K, the ensemble of ferromagnetic nanoislands explore their energy landscape over time and eventually transition to lower energy states as compared to the frozen-in configurations obtained upon cooling from above the Curie temperature. Thus, this materials system allows for a facile method to systematically study thermal evolution of artificial spin ice arrays of nanoislands at temperatures modestly above room temperature.
Finiteness of outer automorphism groups of random right-angled Artin groups

os‐Renyi model. We show that the functions n 1 .log.n/C log.log.n/// and 1 n 1 .log.n/C log.log.n/// bound the range of edge probability functions for which Out.AA/ is finite: if the probability of an edge in A is strictly between these functions as n grows, then asymptotically Out.AA/ is almost surely finite, and if the edge probability is strictly outside of both of these functions, then asymptotically Out.AA/ is almost surely infinite. This sharpens a result of Ruth Charney and Michael Farber. 05C80, 20E36, 20F28, 20F69; 20F05
Towards quasi-transverse momentum dependent PDFs computable on the lattice

Transverse momentum dependent parton distributions (TMDPDFs) which appear in factorized cross sections involve infinite Wilson lines with edges on or close to the light-cone. Since these TMDPDFs are not directly calculable with a Euclidean path integral in lattice QCD, we study the construction of quasi-TMDPDFs with finite-length spacelike Wilson lines that are amenable to such calculations. We define an infrared consistency test to determine which quasi-TMDPDF definitions are related to the TMDPDF, by carrying out a one-loop study of infrared logarithms of transverse position bT ∼ ΛQCD−1, which must agree between them. This agreement is a necessary condition for the two quantities to be related by perturbative matching. TMDPDFs necessarily involve combining a hadron matrix element, which nominally depends on a single light-cone direction, with soft matrix elements that necessarily depend on two light-cone directions. We show at one loop that the simplest definitions of the quasi hadron matrix element, the quasi soft matrix element, and the resulting quasi-TMDPDF all fail the infrared consistency test. Ratios of impact parameter quasi-TMDPDFs still provide nontrivial information about the TMD-PDFs, and are more robust since the soft matrix elements cancel. We show at one loop that such quasi ratios can be matched to ratios of the corresponding TMDPDFs. We also introduce a modified “bent” quasi soft matrix element which yields a quasi-TMDPDF that passes the consistency test with the TMDPDF at one loop, and discuss potential issues at higher orders.
Minimal surfaces in the $3$-sphere by stacking Clifford tori

Extending work of Kapouleas and Yang, for any integers $N \geq 2, {k , \ell} \geq 1$, and m sufficiently large, we apply gluing methods to construct in the round $3$-sphere a closed embedded minimal surface that has genus ${k \ell m}^2 (N-1)+1$ and is invariant under a $D_{km} \times D_{\ell m}$ subgroup of $O(4)$, where $D_n$ is the dihedral group of order $2n$. Each such surface resembles the union of $N$ nested topological tori, all small perturbations of a single Clifford torus $\mathbb{T}$, that have been connected by ${k \ell m}^2(N-1)$ small catenoidal tunnels, with ${k \ell m}^2$ tunnels joining each pair of neighboring tori. In the large-$m$ limit for fixed $N$, $k$, and $\ell$, the corresponding surfaces converge to $\mathbb{T}$ counted with multiplicity $N$.
One-loop renormalization of a gravity-scalar system

Extending the renormalizability proposal of the physical sector of 4D Einstein gravity, we have recently proposed renormalizability of the 3D physical sector of gravity-matter systems. The main goal of the present work is to conduct systematic one-loop renormalization of a gravity-matter system by applying our foliation-based quantization scheme. In this work we explicitly carry out renormalization of a gravity-scalar system with a Higgs-type potential. With the fluctuation part of the scalar field gauged away, the system becomes renormalizable through a metric field redefinition. We use dimensional regularization throughout. One of the salient aspects of our analysis is how the graviton propagator acquires the “mass” term. One-loop calculations lead to renormalization of the cosmological and Newton constants. We discuss other implications of our results as well: time-varying vacuum energy density and masses of the elementary particles as well as the potential relevance of Neumann boundary condition for black hole information.
Cross-identification Performance from Simulated Detections: Galex and SDSS

We investigate the quality of associations of astronomical sources from multi-wavelength observations using simulated detections that are realistic in terms of their astrometric accuracy, small-scale clustering properties and selection functions. We present a general method to build such mock catalogs for studying associations, and compare the statistics of cross-identifications based on angular separation and Bayesian probability criteria. In particular, we focus on the highly relevant problem of cross-correlating the ultraviolet Galaxy Evolution Explorer (GALEX) and optical Sloan Digital Sky Survey (SDSS) surveys. Using refined simulations of the relevant catalogs, we find that the probability thresholds yield lower contamination of false associations, and are more efficient than angular separation. Our study presents a set of recommended criteria to construct reliable cross-match catalogs between SDSS and GALEX with minimal artifacts.
Enhanced n -body annihilation of dark matter and its indirect signatures

We examine the possible indirect signatures of dark matter annihilation processes with a non-standard scaling with the dark matter density, and in particular the case where more than two dark matter particles participate in the annihilation process. We point out that such processes can be strongly enhanced at low velocities without violating unitarity, similar to Sommerfeld enhancement in the standard case of two-body annihilation, potentially leading to visible signals in indirect searches. We study in detail the impact of such multi-body annihilations on the ionization history of the universe and consequently the cosmic microwave background, and find that unlike in the two-body case, the dominant signal can naturally arise from the end of the cosmic dark ages, after the onset of structure formation. We examine the complementary constraints from the Galactic Center, Galactic halo, and galaxy clusters, and outline the circumstances under which each search would give rise to the strongest constraints. We also show that if there is a population of ultra-compact dense dark matter clumps present in the Milky Way with sufficiently steep density profile, then it might be possible to detect point sources illuminated by multi-body annihilation, even if there is no large low-velocity enhancement. Finally, we provide a case study of a model where 3-body annihilation dominates the freezeout process, and in particular the resonant regime where a large low-velocity enhancement is naturally generated.
Rapidity correlations test stochastic hydrodynamics

We show that measurements of the rapidity dependence of transverse momentum correlations can be used to determine the characteristic time τπ that dictates the rate of isotropization of the stress energy tensor, as well as the shear viscosity ν = η/sT. We formulate methods for computing these correlations using second order dissipative hydrodynamics with noise. Current data are consistent with τπ/ν ~ 10 but targeted measurements can improve this precision.
Two roads to the null energy condition

The null energy condition has sweeping consequences in general relativity. I argue here that it has been misunderstood as a property exclusively of matter, when in fact it arises only in a theory of both matter and gravity. I then derive an equivalent geometric formulation of the null energy condition from worldsheet string theory, where it arises beautifully as simple Einstein’s equations in two dimensions. But further, I show that this condition also has a thermodynamic origin, following from a local version of the second law of thermodynamics, applied to gravitational entropy. Thus, far from being an incidental property of matter, the validity of the null energy condition hints at the deep dual origins of gravity.
Semantic Role Labeling as Syntactic Dependency Parsing

We reduce the task of (span-based) PropBank-style semantic role labeling (SRL) to syntactic dependency parsing. Our approach is motivated by our empirical analysis that shows three common syntactic patterns account for over 98% of the SRL annotations for both English and Chinese data. Based on this observation, we present a conversion scheme that packs SRL annotations into dependency tree representations through joint labels that permit highly accurate recovery back to the original format. This representation allows us to train statistical dependency parsers to tackle SRL and achieve competitive performance with the current state of the art. Our findings show the promise of syntactic dependency trees in encoding semantic role relations within their syntactic domain of locality, and point to potential further integration of syntactic methods into semantic role labeling in the future.
SOLAR WAVE-FIELD SIMULATION FOR TESTING PROSPECTS OF HELIOSEISMIC MEASUREMENTS OF DEEP MERIDIONAL FLOWS

The meridional flow in the Sun is an axisymmetric flow that is generally directed poleward at the surface, and is presumed to be of fundamental importance in the generation and transport of magnetic fields. Its true shape and strength, however, are debated. We present a numerical simulation of helioseismic wave propagation in the whole solar interior in the presence of a prescribed, stationary, single-cell, deep meridional circulation serving as synthetic data for helioseismic measurement techniques. A deep-focusing time-distance helioseismology technique is applied to the synthetic data, showing that it can in fact be used to measure the effects of the meridional flow very deep in the solar convection zone. It is shown that the ray approximation that is commonly used for interpretation of helioseismology measurements remains a reasonable approximation even for very long distances between 12° and 42° corresponding to depths between 52 and 195 Mm. From the measurement noise, we extrapolate that time-resolved observations on the order of a full solar cycle may be needed to probe the flow all the way to the base of the convection zone.