cssi/SciSciGPT-SciSciNet huggingface dataset:
Atomic chemistry in turbulent astrophysical media II: Effect of the redshift zero metagalactic background

We carry out direct numerical simulations of turbulent astrophysical media exposed to the redshift zero metagalactic background. The simulations assume solar composition and explicitly track ionizations, recombinations, and ion-by-ion radiative cooling for hydrogen, helium, carbon, nitrogen, oxygen, neon, sodium, magnesium, silicon, sulfur, calcium, and iron. Each run reaches a global steady state that not only depends on the ionization parameter, $U,$ and mass-weighted average temperature, $T_{\rm MW},$ but also on the the one-dimensional turbulent velocity dispersion, \soned. We carry out runs that span a grid of models with $U$ ranging from 0 to 10$^{-1}$ and \soned\ ranging from 3.5 to 58 km s$^{-1}$, and we vary the product of the mean density and the driving scale of the turbulence, $nL,$ which determines the average temperature of the medium, from $nL =10^{16}$ to $nL =10^{20}$ cm$^{-2}$. The turbulent Mach numbers of our simulations vary from $M \approx 0.5$ for the lowest velocity dispersions cases to $M \approx 20$ for the largest velocity dispersion cases. When $M \lesssim1,$ turbulent effects are minimal, and the species abundances are reasonably described as those of a uniform photoionized medium at a fixed temperature. On the other hand, when $M \gtrsim 1,$ dynamical simulations such as the ones carried out here are required to accurately predict the species abundances. We gather our results into a set of tables, to allow future redshift zero studies of the intergalactic medium to account for turbulent effects.
Solar neutrino variability and its implications for solar physics and neutrino physics

Recent coordinated power-spectrum analyses of radiochemical solar neutrino data and the solar irradiance have revealed a highly significant, high-Q common modulation at 11.85 yr−1. Since the stability of this frequency points to an explanation in terms of rotation, this result may be attributable to non-spherically-symmetric nuclear burning in a solar core with sidereal rotation frequency 12.85 yr−1. The variability of the amplitude (on a timescale of years) suggests that the relevant nuclear burning is variable as well as asymmetric. Recent analysis of Super-Kamiokande solar neutrino data has revealed r-mode-type modulations with frequencies corresponding to a region with sidereal rotation frequency 13.97 yr−1. If this modulation is attributed to the RSFP (resonant spin flavor precession) process, it provides a measurement of the rotation rate deep in the radiative zone. These two results suggest that the core rotates significantly more slowly than the radiative zone. If one accepts an upper limit of 7 MG for the Sun's internal magnetic field, an RSFP interpretation of the Super-Kamiokande results leads to a lower limit of 10−12 Bohr magnetons for the neutrino transition magnetic moment.
Complete Coherent Control of a Quantum Dot Strongly Coupled to a Nanocavity

Strongly coupled quantum dot-cavity systems provide a non-linear configuration of hybridized light-matter states with promising quantum-optical applications. Here, we investigate the coherent interaction between strong laser pulses and quantum dot-cavity polaritons. Resonant excitation of polaritonic states and their interaction with phonons allow us to observe coherent Rabi oscillations and Ramsey fringes. Furthermore, we demonstrate complete coherent control of a quantum dot-photonic crystal cavity based quantum-bit. By controlling the excitation power and phase in a two-pulse excitation scheme we achieve access to the full Bloch sphere. Quantum-optical simulations are in good agreement with our experiments and provide insight into the decoherence mechanisms.
Cry Wolf: Toward an Experimentation Platform and Dataset for Human Factors in Cyber Security Analysis

Computer network defense is a partnership between automated systems and human cyber security analysts. The system behaviors, for example raising a high proportion of false alarms, likely impact cyber analyst performance. Experimentation in the analyst-system domain is challenging due to lack of access to security experts, the usability of attack datasets, and the training required to use security analysis tools. This paper describes Cry Wolf, an open source web application for user studies of cyber security analysis tasks. This paper also provides an open-access dataset of 73 true and false Intrusion Detection System (IDS) alarms derived from real-world examples of impossible travel scenarios. Cry Wolf and the impossible travel dataset were used in an experiment on the impact of IDS false alarm rate on analysts' abilities to correctly classify IDS alerts as true or false alarms. Results from that experiment are used to evaluate the quality of the dataset using difficulty and discrimination index measures drawn from classical test theory. Many alerts in the dataset provide good discrimination for participants' overall task performance.
The Trojan Color Conundrum

The Trojan asteroids of Jupiter and Neptune are likely to have been captured from original heliocentric orbits in the dynamically excited ("hot") population of the Kuiper belt. However, it has long been known that the optical color distributions of the Jovian Trojans and the hot population are not alike. This difference has been reconciled with the capture hypothesis by assuming that the Trojans were resurfaced (for example, by sublimation of near-surface volatiles) upon inward migration from the Kuiper belt (where blackbody temperatures are $\sim$40 K) to Jupiter's orbit ($\sim$125 K). Here, we examine the optical color distribution of the \textit{Neptunian} Trojans using a combination of new optical photometry and published data. We find a color distribution that is statistically indistinguishable from that of the Jovian Trojans but unlike any sub-population in the Kuiper belt. This result is puzzling, because the Neptunian Trojans are very cold (blackbody temperature $\sim$50 K) and a thermal process acting to modify the surface colors at Neptune's distance would also affect the Kuiper belt objects beyond, where the temperatures are nearly identical. The distinctive color distributions of the Jovian and Neptunian Trojans thus present us with a conundrum: they are very similar to each other, suggesting either capture from a common source or surface modification by a common process. However, the color distributions differ from any plausible common source population, and there is no known modifying process that could operate equally at both Jupiter and Neptune.
On the equivalence of local and global area-constraint formulations for lipid bilayer vesicles

Lipid bilayer membranes are commonly modeled as area-preserving fluid surfaces that resist bending. There appear to be two schools of thought in the literature concerning the actual area constraint. In some works the total or global area of the vesicle is a prescribed constant, while in others the local area ratio is assigned to unity. In this work we demonstrate the equivalence of these ostensibly distinct approaches in the specific case when the equilibrium configuration is a smooth, closed surface of genus zero. We accomplish this in the context of the Euler–Lagrange equilibrium equations, constraint equations and the second variation with admissibility conditions, for a broad class of models—including the phase-field type. In particular, the two formulations have equivalent equilibria characterized by the same local-energy properties.
Topological concordance of knots in homology spheres and the solvable filtration

In 2016 Levine showed that there exists a knot in a homology 3-sphere which is not smoothly concordant to any knot in the 3-sphere where one allows concordances in any smooth homology cobordism. Whether the same is true if one allows topological concordances is not known. One might hope that such an example might be detected by the powerful filtration of knot concordance introduced by Cochran-Orr-Teichner. We prove that this is not the case, demonstrating that for any knot in any homology sphere there is a knot in the 3-sphere equivalent to the original knot modulo any term of this filtration. Our results apply equally well to link concordance. As an application we prove that every winding number +/-1 satellite operator acts bijectively on knot concordance, modulo any term of the solvable filtration.
Gender Detection on Social Networks using Ensemble Deep Learning

Analyzing the ever-increasing volume of posts on social media sites, such as Facebook and Twitter requires improved information processing methods for profiling authorship. Document classification is central to this task, but the performance of traditional supervised classifiers has degraded as the volume of social media has increased. This paper addresses this problem in the context of gender detection through ensemble classification that employs multi-model deep learning architectures to generate specialized understanding from different feature spaces.
The emergence of modularity in biological systems.

Abstract In this review, we discuss modularity and hierarchy in biological systems. We review examples from protein structure, genetics, and biological networks of modular partitioning of the geometry of biological space. We review theories to explain modular organization of biology, with a focus on explaining how biology may spontaneously organize to a structured form. That is, we seek to explain how biology nucleated from among the many possibilities in chemistry. The emergence of modular organization of biological structure will be described as a symmetry-breaking phase transition, with modularity as the order parameter. Experimental support for this description will be reviewed. Examples will be presented from pathogen structure, metabolic networks, gene networks, and protein–protein interaction networks. Additional examples will be presented from ecological food networks, developmental pathways, physiology, and social networks.
Stellar Properties of Active G and K Stars: Exploring the Connection between Starspots and Chromospheric Activity

We gathered high resolution spectra for an ensemble of 55 bright active and inactive stars using the ARC 3.5 m Telescope Echelle Spectrograph at Apache Point Observatory ($R\approx$31,500). We measured spectroscopic effective temperatures, surface gravities and metallicities for most stars in the sample with SME and MOOG. Our stellar property results are consistent with the photometric effective temperatures from the Gaia DR2 pipeline. We also measured their chromospheric $S$ and $\log R^\prime_\mathrm{HK}$ indices to classify the stars as active or inactive and study the connection between chromospheric activity and starspots. We then attempted to infer the starspot covering fractions on the active stars by modeling their spectra as a linear combination of hot and cool inactive stellar spectral templates. We find that it is critical to use precise colors of the stars to place stringent priors on the plausible spot covering fractions. The inferred spot covering fractions generally increase with the chromospheric activity indicator $\log R^\prime_\mathrm{HK}$, though we are largely insensitive to spot coverages smaller than $f_S \lesssim 20$%. We find a dearth of stars with small $\log R^\prime_\mathrm{HK}$ and significant spot coverages.
The Lifetime of Axion Stars

We investigate the decay of condensates of scalars in a field theory defined by V (&#x1d49c;) = m2f2[1 −cos(&#x1d49c;/f)], where m and f are the mass and decay constant of the scalar field. An example of such a theory is that of the axion, in which case the condensates are called axion stars. The axion field, &#x1d49c;, is self-adjoint. As a result, the axion number is not an absolutely conserved quantity. Therefore, axion stars are not stable and have finite lifetimes. Bound axions, localized on the volume of the star, have a coordinate uncertainty δx ∼ R ∼ 1/(maΔ), where R is the radius of the star and Δ = 1 − E0 2/ma 2. Here ma and E0 are the mass, and the ground state energy of the bound axion. Then the momentum distribution of axions has a width of δp ∼ maΔ. At strong binding, Δ = &#x1d4aa;(1), bound axions can easily transfer a sufficient amount of momentum to create and emit a free axion, leading to fast decay of the star with a transition rate Γ ∼ ma. However, when Δ ≪ 1, the momentum distribution is more restricted, and as show...
Stellar tidal disruption events in general relativity

A tidal disruption event (TDE) ensues when a star passes too close to a supermassive black hole (SMBH) in a galactic center, and is ripped apart by its tidal field. The gaseous debris produced in a TDE can power a bright electromagnetic flare as it is accreted by the SMBH; so far, several dozen TDE candidates have been observed. For SMBHs with masses above $$\sim 10^7 M_\odot $$ , the tidal disruption of solar-type stars occurs within ten gravitational radii of the SMBH, implying that general relativity (GR) is needed to describe gravity. Three promising signatures of GR in TDEs are: (1) a super-exponential cutoff in the volumetric TDE rate for SMBH masses above $$\sim 10^8 M_\odot $$ due to direct capture of tidal debris by the event horizon, (2) delays in accretion disk formation (and a consequent alteration of the early-time light curve) caused by the effects of relativistic nodal precession on stream circularization, and (3) quasi-periodic modulation of X-ray emission due to global precession of misaligned accretion disks and the jets they launch. We review theoretical models and simulations of TDEs in Newtonian gravity, then describe how relativistic modifications give rise to these proposed observational signatures, as well as more speculative effects of GR. We conclude with a brief summary of TDE observations and the extent to which they show indications of these predicted relativistic signatures.
Scattering of low-energy electrons and positrons by atomic beryllium: Ramsauer–Townsend effect

Total cross sections for the scattering of low-energy electrons and positrons by atomic beryllium in the energy range below the first inelastic thresholds are calculated. A Ramsauer–Townsend minimum is seen in the electron scattering cross sections, while no such effect is found in the case of positron scattering. A minimum total cross section of 0.016 a02 at 0.0029 eV is observed for the electron case. In the limit of zero energy, the cross sections yield a scattering length of −0.61 a0 for electron and a0 for positron scattering.
THREE-DIMENSIONAL ATMOSPHERIC CIRCULATION MODELS OF HD 189733b AND HD 209458b WITH CONSISTENT MAGNETIC DRAG AND OHMIC DISSIPATION

We present the first three-dimensional circulation models for extrasolar gas giant atmospheres with geometrically and energetically consistent treatments of magnetic drag and ohmic dissipation. Atmospheric resistivities are continuously updated and calculated directly from the flow structure, strongly coupling the magnetic effects with the circulation pattern. We model the hot Jupiters HD 189733b (T eq 1200?K) and HD 209458b (T eq 1500?K) and test planetary magnetic field strengths from 0 to 30?G. We find that even at B = 3?G the atmospheric structure and circulation of HD 209458b are strongly influenced by magnetic effects, while the cooler HD 189733b remains largely unaffected, even in the case of B = 30?G and super-solar metallicities. Our models of HD 209458b indicate that magnetic effects can substantially slow down atmospheric winds, change circulation and temperature patterns, and alter observable properties. These models establish that longitudinal and latitudinal hot spot offsets, day-night flux contrasts, and planetary radius inflation are interrelated diagnostics of the magnetic induction process occurring in the atmospheres of hot Jupiters and other similarly forced exoplanets. Most of the ohmic heating occurs high in the atmosphere and on the dayside of the planet, while the heating at depth is strongly dependent on the internal heat flux assumed for the planet, with more heating when the deep atmosphere is hot. We compare the ohmic power at depth in our models, and estimates of the ohmic dissipation in the bulk interior (from general scaling laws), to evolutionary models that constrain the amount of heating necessary to explain the inflated radius of HD 209458b. Our results suggest that deep ohmic heating can successfully inflate the radius of HD 209458b for planetary magnetic field strengths of B ? 3-10?G.
NON-EXISTENCE OF LOCAL INTEGRALS OF MOTION IN THE MULTI-DEFORMED ISING MODEL

We confirm the non-integrability of the multi-deformed Ising model — an already expected result. After deforming with the energy operator ϕ1,3, we use the Majorana free fermionic representation for the massive theory to show that, besides the trivial one, no local integrals of motion can be built in the theory arising from perturbing with both energy and spin operators.
Topology Dependent Bounds For FAQs

In this paper, we prove topology dependent bounds on the number of rounds needed to compute Functional Aggregate Queries ($\FAQ$s) studied by Abo Khamis et al. [PODS 2016] in a synchronous distributed network under the model considered by Chattopadhyay et al. [FOCS 2014, SODA 2017]. Unlike the recent work on computing database queries in the Massively Parallel Computation model, in the model of Chattopadhyay et al., nodes can communicate only via private point-to-point channels and we are interested in bounds that work over an \em arbitrary communication topology. This model, which is closer to the well-studied $\congest$ model in distributed computing and generalizes Yao's two party communication complexity model, has so far only been studied for problems that are common in the two-party communication complexity literature. This is the first work to consider more practically motivated problems in this distributed model. For the sake of exposition, we focus on two specific problems in this paper: Boolean Conjunctive Query ($\BCQ$) and computing variable/factor marginals in Probabilistic Graphical Models (PGMs). We obtain tight bounds on the number of rounds needed to compute such queries as long as the underlying hypergraph of the query is $O(1)$-degenerate and has $O(1)$-arity. In particular, the $O(1)$-degeneracy condition covers most well-studied queries that are efficiently computable in the centralized computation model like queries with constant treewidth. These tight bounds depend on a new notion of 'width' (namely \em internal-node-width ) for Generalized Hypertree Decompositions (GHDs) of acyclic hypergraphs, which minimizes the number of internal nodes in a sub-class of GHDs. To the best of our knowledge, this width has not been studied explicitly in the theoretical database literature. Finally, we consider the problem of computing the product of a vector with a chain of matrices and prove tight bounds on its round complexity (over a finite field of two elements) using a novel min-entropy based argument.
STRUCTURE OF STATIONARY STRONG IMBALANCED TURBULENCE

In this paper we systematically study the spectrum and structure of incompressible MHD turbu- lence by means of high resolution direct numerical simulations. We considered both balanced and imbalanced (cross-helical) cases and simulated sub-Alfvenic as well as trans-Alfvenic turbulence. This paper extends numerics preliminarily reported in Beresnyak & Lazarian 2008. We confirm that driven imbalanced turbulence has a stationary state even for high degrees of imbalance. Our major finding is that the structure of the dominant and subdominant Alfvenic components are notably different. Using the most robust observed quantities, such as the energy ratio, we believe we can reject several existing models of strong imbalanced turbulence. Subject headings: MHD - turbulence - ISM: kinematics and dynamics
Time Global Finite-Energy Weak Solutions to the Many-Body Maxwell–Pauli Equations

We study the quantum mechanical many-body problem of $$N \ge 1$$ non-relativistic electrons with spin interacting with their self-generated classical electromagnetic field and $$K \ge 0$$ static nuclei. We model the dynamics of the electrons and their self-generated electromagnetic field with the so-called many-body Maxwell–Pauli equations. Here we construct time global, finite-energy, weak solutions to the many-body Maxwell–Pauli equations under the assumption that the fine structure constant $$\alpha $$ and the nuclear charges are not too large. The particular assumptions on the size of $$\alpha $$ and the nuclear charges ensure that we have energetic stability of the many-body Pauli Hamiltonian, i.e., the ground state energy is finite and uniformly bounded below with lower bound independent of the magnetic field and the positions of the nuclei. This work serves as an initial step towards understanding the connection between the energetic stability of matter and the well-posedness of the corresponding dynamical equations.
High energy scattering amplitudes in Matrix string theory

Abstract High energy fixed angle scattering is studied in Matrix string theory. The saddle-point world-sheet configurations, which give the dominant contributions to the string theory amplitude, are taken as classical backgrounds in Matrix string theory. A one loop fluctuation analysis about the classical background is performed. An exact treatment of the fermionic and bosonic zero modes is shown to lead to all of the expected structure of the scattering amplitude. The ten-dimensional Lorentz invariant kinematical structure is obtained from the fermion zero modes, and the correct factor of the string coupling constant is obtained from the Abelian gauge field zero modes. Up to a numerical factor we reproduce, from Matrix string theory, the high energy limit of the tree level, four graviton scattering amplitude.
THE DISTRIBUTION OF r-FREE NUMBERS IN ARITHMETIC PROGRESSIONS

Let r ≥ 2. A positive integer n is called r-free if n is not divisible by the rth power of a prime. Generalizing an earlier work of Orr, we provide an upper bound of Bombieri–Vinogradov type for the r-free numbers in arithmetic progressions.
Luminosities of Radio Pulsars

Luminosity is an intrinsic property of radio pulsars related to the properties of the magnetospheric plasma and the beam geometry, and inversely proportional to the observing frequency. In traditional models, luminosity has been considered as a function of the spin parameters of pulsars. On the other hand, parameter independent models like power law and lognormal have been also used to fit the observed luminosities. Some of the older studies on pulsar luminosities neglected observational biases, but all of the recent studies tried to model observational effects as accurately as possible. Luminosities of pulsars in globular clusters (GCs) and in the Galactic disk have been studied separately. Older studies concluded that these two categories of pulsars have different luminosity distributions, but the most recent study concluded that those are the same. This paper reviews all significant works on pulsar luminosities and discusses open questions.
Breaking local baryon and lepton number at the TeV scale

Simple models are proposed where the baryon and lepton number are gauged and spontaneously broken near the weak scale. The models use a fourth generation that is vector-like with respect to the strong, weak and electromagnetic interactions to cancel anomalies. One does not need large Yukawa couplings to be consistent with the experimental limits on fourth generation quark masses and hence the models are free of coupling constants with Landau poles near the weak scale. We discuss the main features of simple non-supersymmetric and supersymmetric models. In these models the light neutrino masses are generated through the seesaw mechanism and proton decay is forbidden even though B and L are broken near the weak scale. For some values of the parameters in these models baryon and/or lepton number violation can be observed at the Large Hadron Collider.
The Puzzle of the Bottom Quark Production Cross Section

The production rate of bottom quarks at hadron colliders exceeds the expectations of next-to-leading order perturbative quantum chromodynamics. An additional contribution from pair-production of light gluinos, of mass 12 to 16 GeV, with two-body decays into bottom quarks and light bottom squarks, yields a differential cross section for bottom quarks in better agreement with data. The masses of the gluino and bottom squark are restricted further by the ratio of like-sign to opposite-sign leptons at hadron colliders. Restrictions on this scenario from other data are summarized, and predictions are made for other processes such as Upsilon decay into a pair of bottom squarks.
UltraViolet Freeze-in

If dark matter is thermally decoupled from the visible sector, the observed relic density can potentially be obtained via freeze-in production of dark matter. Typically in such models it is assumed that the dark matter is connected to the thermal bath through feeble renormalisable interactions. Here, rather, we consider the case in which the hidden and visible sectors are coupled only via non-renormalisable operators. This is arguably a more generic realisation of the dark matter freeze-in scenario, as it does not require the introduction of diminutive renormalisable couplings. We examine general aspects of freeze-in via non-renormalisable operators in a number of toy models and present several motivated implementations in the context of Beyond the Standard Model (BSM) physics. Specifically, we study models related to the Peccei-Quinn mechanism and Z ′ portals.
The epidemiology of lateral movement: exposures and countermeasures with network contagion models

An approach is developed for analyzing computer networks to identify systems and accounts that are at particular risk of compromise by an adversary seeking to move laterally through the network via...
Topological structure in the SU(2) vacuum

We study the topological content of the vacuum of SU(2) pure gauge theory using lattice simulations. We use a smoothing process based on the renormalization group equation which removes short distance fluctuations but preserves long distance structure. The action of the smoothed configurations is dominated by instantons, but they still show an area law for Wilson loops with a string tension equal to the string tension on the original configurations. Yet it appears that instantons are not directly responsible for confinement. The average radius of an instanton is about 0.2 fm, at a density of about 2 fm 4 . This is a much smaller average size than other lattice studies have indicated. The instantons appear not to be randomly distributed in space, but are clustered.
Locality in free string field theory: II

We study the covariant free bosonic string field theory and explore its locality (causality) properties. We find string fields which are strictly local and covariant, but act on an unconstrained Hilbert space with an indefinite inner product. From these we construct observable fields which act on the physical Hilbert space with a definite inner product. These are shown to be approximately local.
Classification of \({{\mathfrak{sl}}_3}\) Relations in the Witt Group of Nondegenerate Braided Fusion Categories

The Witt group of nondegenerate braided fusion categories \({{\mathcal{W}}}\) contains a subgroup \({{\mathcal{W}}_{\rm un}}\) consisting of Witt equivalence classes of pseudo-unitary nondegenerate braided fusion categories. For each finite dimensional simple Lie algebra \({{\mathfrak{g}}}\) and positive integer k there exists a pseudo-unitary category \({{\mathcal{C}}({\mathfrak{g}},k)}\) consisting of highest weight integrable \({{\hat{g}}}\)-modules of level k where \({\hat{{\mathfrak{g}}}}\) is the corresponding affine Lie algebra. Relations between the classes \({[{\mathcal{C}}({\mathfrak{sl}}_2,k)]}\), \({k\geq1}\) have been completely described in the work of Davydov, Nikshych, and Ostrik. Here we give a complete classification of relations between the classes \({[{\mathcal{C}}({\mathfrak{sl}}_3,k)]}\), \({k\geq1}\) with a view toward extending these methods to arbitrary simple finite dimensional Lie algebras \({{\mathfrak{g}}}\) and positive integer levels k.
Low-Degree Testing for Quantum States, and a Quantum Entangled Games PCP for QMA

We show that given an explicit description of a multiplayer game, with a classical verifier and a constant number of players, it is QMA-hard, under randomized reductions, to distinguish between the cases when the players have a strategy using entanglement that succeeds with probability 1 in the game, or when no such strategy succeeds with probability larger than 1/2. This proves the "games quantum PCP conjecture" of Fitzsimons and the second author (ITCS'15), albeit under randomized reductions. The core component in our reduction is a construction of a family of two-player games for testing n-qubit maximally entangled states. For any integer n >= 2, we give such a game in which questions from the verifier are O(log n) bits long, and answers are poly(log log n) bits long. We show that for any constant eps >= 0, any strategy that succeeds with probability at least 1-eps in the test must use a state that is within distance δ(eps) = O(eps^c) from a state that is locally equivalent to a maximally entangled state on n qubits, for some universal constant c > 0. The construction is based on the classical plane-vs-point test for multivariate low-degree polynomials of Raz and Safra. We extend the classical test to the quantum regime by executing independent copies of the test in the generalized Pauli X and Z bases over F_q, where q is a sufficiently large prime power, and combine the two through a test for the Pauli twisted commutation relations. Our main complexity-theoretic result is obtained by combining this game with techniques from the classical PCP literature. More specifically, we use constructions of PCPs of proximity introduced by Ben-Sasson et al. (CCC'05), and crucially rely on a linear property of such PCPs. Another consequence of our reduction is a deterministic reduction from the games quantum PCP conjecture to a suitable formulation of the constraint satisfaction quantum PCP conjecture.
Delocalization of boundary states in disordered topological insulators

We use the method of bulk-boundary correspondence of topological invariants to show that disordered topological insulators have at least one delocalized state at their boundary at zero energy. Those insulators which do not have chiral (sublattice) symmetry have in addition the whole band of delocalized states at their boundary, with the zero energy state lying in the middle of the band. This result was previously conjectured based on the anticipated properties of the supersymmetric (or replicated) sigma models with WZW-type terms, as well as verified in some cases using numerical simulations and a variety of other arguments. Here we derive this result generally, in arbitrary number of dimensions, and without relying on the description in the language of sigma models.
Analysis of High Cadence In Situ Solar Wind Ionic Composition Data Using Wavelet Power Spectra Confidence Levels

The variability inherent in solar wind composition has implications for the variability of the physical conditions in its coronal source regions, providing constraints on models of coronal heating and solar wind generation. We present a generalized prescription for constructing a wavelet power significance measure (confidence level) for the purpose of characterizing the effects of missing data in high cadence solar wind ionic composition measurements. We describe the data gaps present in the 12 minute Advanced Composition Explorer/Solar Wind Ionic Composition Spectrometer observations of O7 +/O6 + during 2008. The decomposition of the in situ observations into good measurement and no-measurement signals allows us to evaluate the performance of a filler signal, i.e., various prescriptions for filling the data gaps. We construct Monte Carlo simulations of synthetic O7 +/O6 + composition data and impose the actual data gaps that exist in the observations in order to investigate two different filler signals: one, a linear interpolation between neighboring good data points, and two, the constant mean value of the measured data. Applied to these synthetic data plus filler signal combinations, we quantify the ability of the power spectra significance level procedure to reproduce the ensemble-averaged time-integrated wavelet power per scale of an ideal case, i.e., the synthetic data without imposed data gaps. Finally, we present the wavelet power spectra for the O7 +/O6 + data using the confidence levels derived from both the mean value and linear interpolation data gap filling signals and discuss the results.
On Zero Forcing Number of Graphs and Their Complements

The zero forcing number, Z(G), of a graph G is the minimum cardinality of a set S of black vertices (whereas vertices in V(G)\S are colored white) such that V(G) is turned black after finitely many applications of "the color-change rule": a white vertex is converted to a black vertex if it is the only white neighbor of a black vertex. Zero forcing number was introduced and used to bound the minimum rank of graphs by the "AIM Minimum Rank-Special Graphs Work Group". It is known that Z(G) ≥ δ(G), where δ(G) is the minimum degree of G. We show that Z(G) ≤ n - 3 if a connected graph G of order n has a connected complement graph . Further, we characterize a tree or a unicyclic graph G which satisfies either or .
Landau Quasiparticles in Weak Power-Law Liquids

The failure of Landau-Fermi liquid theory is often considered a telltale sign of universal, scale-invariant behavior in the emergent field theory of interacting fermions. Nevertheless, there exist borderline cases where weak scale invariance coupled with particle-hole asymmetry can coexist with the Landau quasiparticle paradigm. In this letter, I show explicitly that a Landau-Fermi liquid can exist for weak power-law scaling of the retarded Green’s function. Such an exotic variant of the traditional Fermi liquid is shown to always be incompatible with Luttinger’s theorem for any non-trivial scaling. This result yields evidence for a Fermi liquid-like ground state in the high-field, underdoped pseudogap phase of the high-temperature cuprate superconductors.
Quantum characteristic classes and the Hofer metric

Given a closed monotone symplectic manifold M , we define certain characteristic cohomology classes of the free loop space LHam.M; !/ with values in QH .M / , and their S equivariant version. These classes generalize the Seidel representation and satisfy versions of the axioms for Chern classes. In particular there is a Whitney sum formula, which gives rise to a graded ring homomorphism from the ring H .Ham.M; !/;Q/ , with its Pontryagin product to QH2nC .M / with its quantum product. As an application we prove an extension to higher dimensional geometry of the loop space LHam.M; !/ of a theorem of McDuff and Slimowitz on minimality in the Hofer metric of a semifree Hamiltonian circle action.
Efficient photon coupling from a diamond nitrogen vacancy center by integration with silica fiber

A central goal in quantum information science is to efficiently interface photons with single optical modes for quantum networking and distributed quantum computing. Here, we introduce and experimentally demonstrate a compact and efficient method for the low-loss coupling of a solid-state qubit, the nitrogen vacancy (NV) center in diamond, with a single-mode optical fiber. In this approach, single-mode tapered diamond waveguides containing exactly one high quality NV memory are selected and integrated on tapered silica fibers. Numerical optimization of an adiabatic coupler indicates that near-unity-efficiency photon transfer is possible between the two modes. Experimentally, we find an overall collection efficiency between 16% and 37% and estimate a single photon count rate at saturation above 700 kHz. This integrated system enables robust, alignment-free, and efficient interfacing of single-mode optical fibers with single photon emitters and quantum memories in solids. A compact way to efficiently couple a solid-state qubit, the nitrogen vacancy center in diamond, with a single-mode optical fiber is shown. The ability to efficiently couple stationary quantum memories to a single spatial mode in a silica fiber is highly desired for various applications in quantum information processing. Now, Rishi Patel and co-workers, working in the group of Dirk Englund at the Massachusetts Institute of Technology have proposed and experimentally demonstrated an approach involving adiabatic power transfer between a tapered silica fiber and a single-mode micro-waveguide made from high-quality diamond. This integrated diamond–silica waveguide system enables optical collection from nitrogen vacancy centers with overall efficiencies in the range 16%–37%—a roughly four-fold improvement over previous approaches that employed diamond point emitters rather than waveguiding structures. Numerical optimization analysis suggests that near-unity efficiencies are theoretically feasible.
Transport Effects on Multiple-Component Reactions in Optical Biosensors

Optical biosensors are often used to measure kinetic rate constants associated with chemical reactions. Such instruments operate in the surface-volume configuration, in which ligand molecules are convected through a fluid-filled volume over a surface to which receptors are confined. Currently, scientists are using optical biosensors to measure the kinetic rate constants associated with DNA translesion synthesis-a process critical to DNA damage repair. Biosensor experiments to study this process involve multiple interacting components on the sensor surface. This multiple-component biosensor experiment is modeled with a set of nonlinear integrodifferential equations (IDEs). It is shown that in physically relevant asymptotic limits these equations reduce to a much simpler set of ordinary differential equations (ODEs). To verify the validity of our ODE approximation, a numerical method for the IDE system is developed and studied. Results from the ODE model agree with simulations of the IDE model, rendering our ODE model useful for parameter estimation.
Static and dynamic critical phenomena at a second order QCD phase transition

Abstract In QCD with two flavors of massless quarks, the chiral phase transition is plausibly in the same universality class as the classical four-component Heisenberg antiferromagnet. Therefore, renormalization group techniques developed in the study of phase transitions can be applied to calculate the critical exponents which characterize the scaling behaviour of universal quantities near the critical point. This approach to the QCD phase transition has implications both for lattice gauge theory and for heavy ion collisions. Future lattice simulations with longer correlation lengths will be able to measure the various exponents and the equation of state for the order parameter as a function of temperature and quark mass which we describe. In a heavy ion collision, the consequence of a long correlation length would be large fluctuations in the number ratio of neutral to charged pions. Unfortunately, we show that this phenomenon will not occur if the plasma stays close to equilibrium as it cools. If the transition is far out of equilibrium and can be modelled as a quench, it is possible that large volumes of the plasma with the pion field oscillating coherently will develop, with dramatic phenomenological consequences.
Optical Parametric Generation in a Lithium Niobate Microring with Modal Phase Matching

Optical parametric generation is important for the creation and control of classical and quantum light. Here LiNbO${}_{3}$ microresonators have not yet lived up to their potential, due to the need for careful design of both phase matching and light extraction in high-$Q$ resonators. This study achieves cavity-enhanced second-harmonic generation with a conversion efficiency of 1500% W${}^{\ensuremath{-}1}$, by using a high-$Q$ Z-cut LiNbO${}_{3}$ microring resonator with a single bus waveguide to couple the phase-matched modes. Difference-frequency generation is also observed. This work is an important step toward efficient wavelength conversion and optical signal processing in integrated photonic circuits.
The fundamental group and Betti numbers of toric origami manifolds

Toric origami manifolds are characterized by origami templates, which are combinatorial models built by gluing polytopes together along facets. In this paper, we examine the topology of orientable toric origami manifolds with coorientable folding hypersurface. We determine the fundamental group. In our previous paper, we studied the ordinary and equivariant cohomology rings of simply connected toric origami manifolds. We conclude this paper by computing some Betti numbers and cohomology rings in the non-simply connected case. 53D20; 55N91, 57R91
The mass dependence of dwarf satellite galaxy quenching

We combine observations of the Local Group with data from the NASA-Sloan Atlas to show the variation in the quenched fraction of satellite galaxies from low-mass dwarf spheroidals and dwarf irregulars to more massive dwarfs similar to the Magellanic Clouds. While almost all of the low-mass (M 107 M ☉) dwarfs are quenched, at higher masses the quenched fraction decreases to approximately 40%-50%. This change in the quenched fraction is large and suggests a sudden change in the effectiveness of quenching that correlates with satellite mass. We combine this observation with models of satellite infall and ram pressure stripping to show that the low-mass satellites must quench within 1-2 Gyr of pericenter passage to maintain a high quenched fraction, but that many more massive dwarfs must continue to form stars today even though they likely fell into their host >5 Gyr ago. We also characterize how the susceptibility of dwarfs to ram pressure must vary as a function of mass if it is to account for the change in quenched fractions. Though neither model predicts the quenching effectiveness a priori, this modeling illustrates the physical requirements that the observed quenched fractions place on possible quenching mechanisms.
Short-Timescale Variability in the External Shock Model of Gamma-Ray Bursts

We have developed a computer model to calculate gamma-ray burst (GRB) light curves and efficiencies from the interaction of a single, thin blast wave with clouds in the external medium. Large-amplitude, short-timescale variability occurs when the clouds have radii rR/Γ, where R is the mean distance of a cloud from the GRB source and Γ is the blast-wave Lorentz factor. Efficiencies 10% require a large number of small clouds, each with sufficiently large column densities to extract most of the available blast-wave energy in the region of interaction. The number and duration of pulses in the simulated GRB light curves are compared with the respective properties found in GRB light curves. If GRB sources are surrounded by clouds with such properties, then short-timescale variability of GRBs can be obtained in the external shock model.
Performance of the HgCdTe detector for MOSFIRE, an imager and multi-object spectrometer for Keck Observatory

MOSFIRE is a new multi-object near-infrared spectrometer for the Keck 1 telescope with a spectral resolving power of R~3500 for a 0.7″ slit (2.9 pixels). The detector is a substrate-removed 2K × 2K HAWAII 2-RG HgCdTe array from Teledyne Imaging Sensors with a cut-off wavelength of 2.5 μm and an operational temperature of 77K. Spectroscopy of faint objects sets the requirement for low dark current and low noise. MOSFIRE is also an infrared camera with a 6.9′ field of view projected onto the detector with 0.18″ pixel sampling. Broad-band imaging drives the requirement for 32-channel readout and MOSFIREs fast camera optics implies the need for a very at detector. In this paper we report the final performance of the detector selected for MOSFIRE. The array is operated using the SIDECAR ASIC chip inside the MOSFIRE dewar and v2.3 of the HxRG software. Dark current plus instrument background is measured at <0.008 ē s^(−1) pixel^−1 on average. Multiple Correlated Double Sampling (MCDS) and Up-The-Ramp (UTR) sampling are both available. A read noise of <5ē rms is achieved with MCDS 16 and the lowest noise of 3ē rms occurs for 64 samples. Charge persistence depends on exposure level and shows a large gradient across this detector. However, the decay time constant is always ~660 seconds. Linearity and stability are also discussed.
Effective unidirectional pumping for steady-state amplification without inversion

We discuss an opportunity to achieve amplification without inversion in a three-level cascade scheme using an effective unidirectional pumping via bidirectional incoherent pump. Analytical solution to the population and the coherence are obtained in the steady-state regime. With a proper choice of the parameters, obtained here, the possibility for amplification without inversion is presented.
Predicting Specificity in Classroom Discussion

High quality classroom discussion is important to student development, enhancing abilities to express claims, reason about other students’ claims, and retain information for longer periods of time. Previous small-scale studies have shown that one indicator of classroom discussion quality is specificity. In this paper we tackle the problem of predicting specificity for classroom discussions. We propose several methods and feature sets capable of outperforming the state of the art in specificity prediction. Additionally, we provide a set of meaningful, interpretable features that can be used to analyze classroom discussions at a pedagogical level.
Existence of Two-Step Replica Symmetry Breaking for the Spherical Mixed p -Spin Glass at Zero Temperature

We provide the first examples of two-step replica symmetry breaking (2-RSB) models for the spherical mixed p-spin glass at zero temperature. Precisely, we show that for a certain class of mixtures, the Parisi measure at zero temperature is purely atomic and has exactly three distinct points in its support. We then derive a few consequences for the topology of the random landscape in these cases. Our main result also provides a negative answer to a question raised in 2011 by Auffinger and Ben Arous about the classification of pure-like and full mixture models.
The most irrational rational theories

We propose a two-parameter family of modular invariant partition functions of two-dimensional conformal field theories (CFTs) holographically dual to pure three-dimensional gravity in anti de Sitter space. Our two parameters control the central charge, and the representation of SL(2, ℤ). At large central charge, the partition function has a gap to the first nontrivial primary state of $$ \frac{c}{24} $$ . As the SL(2, ℤ) representation dimension gets large, the partition function exhibits some of the qualitative features of an irrational CFT. This, for instance, is captured in the behavior of the spectral form factor. As part of these analyses, we find similar behavior in the minimal model spectral form factor as c approaches 1.
Three-body unitarity with isobars revisited

The particle exchange model of hadron interactions can be used to describe three-body scattering under the isobar assumption. In this study we start from the $3\rightarrow 3$ scattering amplitude for spinless particles, which contains an isobar-spectator scattering amplitude. Using a Bethe-Salpeter Ansatz for the latter, we derive a relativistic three-dimensional scattering equation that manifestly fulfills three-body unitarity and two-body unitarity for the sub-amplitudes. This property holds for energies above breakup and also in the presence of resonances in the sub-amplitudes.
Schwinger-Dyson = Wheeler-DeWitt: gauge theory observables as bulk operators

We argue that the second-order gauge-invariant Schwinger-Dyson operator of a gauge theory is the Wheeler-DeWitt operator in the dual string theory. Using this identification, we construct a set of operators in the gauge theory that correspond to excitations of gravity in the bulk. We show that these gauge theory operators have the expected properties for describing the semi-classical local gravity theory.