cssi/SciSciGPT-SciSciNet huggingface dataset:
Implications of Captured Interstellar Objects for Panspermia and Extraterrestrial Life

We estimate the capture rate of interstellar objects by means of three-body gravitational interactions. We apply this model to the Sun-Jupiter system and the Alpha Centauri A\&B binary system, and find that the radius of the largest captured object is a few tens of km and Earth-sized respectively. We explore the implications of our model for the transfer of life by means of rocky material. The interstellar comets captured by the "fishing net" of the Solar system can be potentially distinguished by their differing orbital trajectories and ratios of oxygen isotopes through high-resolution spectroscopy of water vapor in their tails.
Coding for memory with stuck-at defects

In this paper, we propose an encoding scheme for partitioned linear block codes (PLBC) which mask the stuck-at defects in memories. In addition, we derive an upper bound and the estimate of the probability that masking fails. Numerical results show that PLBC can efficiently mask the defects with the proposed encoding scheme. Also, we show that our upper bound is very tight by using numerical results.
On Calabi–Yau generalized complete intersections from Hirzebruch varieties and novel $K3$-fibrations

We consider the construction of Calabi-Yau varieties recently generalized to where the defining equations may have negative degrees over some projective space factors in the embedding space. Within such "generalized complete intersection" Calabi-Yau ("gCICY") three-folds, we find several sequences of distinct manifolds. These include both novel elliptic and K3-fibrations and involve Hirzebruch surfaces and their higher dimensional analogues. En route, we generalize the standard techniques of cohomology computation to these generalized complete intersection Calabi-Yau varieties.
Did Mali benefit from joining the CFA zone? An analysis using the synthetic control method

This article examines the benefits of CFA zone membership by estimating the effects of joining the CFA zone on short‐run business cycle indicators such as income per capita and inflation as well as long‐term economic indicators such as trade relations with France and foreign direct investment (FDI) in Mali. Using the synthetic control method, we show that Mali’s CFA membership has a positive effect on its income, inflation, and FDI but no discernible effect on trade relations with France. We conclude that joining the CFA zone can generate potential economic gains for countries seeking membership by fostering growth and providing price stability but does not necessarily increase trade relations with France even though the CFA is a former French colonial currency.
Translating video recordings of mobile app usages into replayable scenarios

Screen recordings of mobile applications are easy to obtain and capture a wealth of information pertinent to software developers (e.g., bugs or feature requests), making them a popular mechanism for crowdsourced app feedback. Thus, these videos are becoming a common artifact that developers must manage. In light of unique mobile development constraints, including swift release cycles and rapidly evolving platforms, automated techniques for analyzing all types of rich software artifacts provide benefit to mobile developers. Unfortunately, automatically analyzing screen recordings presents serious challenges, due to their graphical nature, compared to other types of (textual) artifacts. To address these challenges, this paper introduces V2S, a lightweight, automated approach for translating video recordings of Android app usages into replayable scenarios. V2S is based primarily on computer vision techniques and adapts recent solutions for object detection and image classification to detect and classify user actions captured in a video, and convert these into a replayable test scenario. We performed an extensive evaluation of V2S involving 175 videos depicting 3,534 GUI-based actions collected from users exercising features and reproducing bugs from over 80 popular Android apps. Our results illustrate that V2S can accurately replay scenarios from screen recordings, and is capable of reproducing ≈ 89% of our collected videos with minimal overhead. A case study with three industrial partners illustrates the potential usefulness of V2S from the viewpoint of developers.
Heliosheath Properties Measured from a Voyager 2 to Voyager 1 Transient

In mid-2012, a GMIR observed by Voyager 2 crossed through the heliosheath and collided with the heliopause, generating a pressure pulse that propagated into the very local interstellar medium. The effects of the transmitted wave were seen by Voyager 1 just 93 days after its own heliopause crossing. The passage of the transient was accompanied by long-lasting decreases in galactic cosmic ray intensities that occurred from ~2012.55 to ~2013.35 and ~2012.91 to ~2013.70 at Voyager 2 and Voyager 1, respectively. Omnidirectional (>20 MeV) proton-dominated measurements from each spacecraft's Cosmic Ray Subsystem reveal a remarkable similarity between these causally-related events, with a correlation coefficient of 91.2% and a time-lag of 130 days. Knowing the locations of the two spacecraft, we use the observed time-delay to calculate the GMIR's average speed through the heliosheath (inside the heliopause) as a function of temperature in the very local interstellar medium. This, combined with particle, field, and plasma observations enables us to infer previously unmeasured properties of the heliosheath, including a range of sound speeds and total effective pressures. For a nominal temperature of ~20,000 K just outside the heliopause, we find a sound speed of 314 (+/-) 32 km/s and total effective pressure of 267 (+/-) 55 fPa inside the heliopause. We compare these results with the Interstellar Boundary Explorer's data-driven models of heliosheath pressures derived from energetic neutral atom fluxes (the globally distributed flux) and present them as additional evidence that the heliosheath's dynamics are driven by suprathermal energetic processes.
A general Schwarz lemma for almost-Hermitian manifolds

We prove a version of Yau's Schwarz Lemma for general almost-complex manifolds equipped with Hermitian metrics. This requires an extension to this setting of the Laplacian comparison theorem. As an application we show that the product of two almost-complex manifolds does not admit any complete Hermitian metric with bisectional curvature bounded between two negative constants that satisfies some additional mild assumptions.
The Effective Surface Area of Amorphous Solid Water Measured by the Infrared Absorption of Carbon Monoxide

The need to characterize ices coating dust grains in dense interstellar clouds arises from the importance of ice morphology in facilitating the diffusion and storage of radicals and reaction products in ices, a well-known place for the formation of complex molecules. Yet, there is considerable uncertainty about the structure of ISM ices, their ability to store volatiles and under what conditions. We measured the infrared absorption spectra of CO on the pore surface of porous amorphous solid water (ASW), and quantified the effective pore surface area of ASW. Additionally, we present results obtained from a Monte Carlo model of ASW in which the morphology of the ice is directly visualized and quantified. We found that 200 ML of ASW annealed to 20 K has a total pore surface area that is equivalent to 46 ML. This surface area decreases linearly with temperature to about 120 K. We also found that (1) dangling OH bonds only exist on the surface of pores; (2) almost all of the pores in the ASW are connected to the vacuum--ice interface, and are accessible for adsorption of volatiles from the gas phase; there are few closed cavities inside ASW at least up to a thickness of 200 ML; (3) the total pore surface area is proportional to the total 3-coordinated water molecules in the ASW in the temperature range 60--120 K. We also discuss the implications on the structure of ASW and surface reactions in the ice mantle in dense clouds.
Modelling a hydrodynamic instability in freely settling colloidal gels

Attractive colloidal dispersions, suspensions of fine particles which aggregate and frequently form a space-spanning elastic gel are ubiquitous materials in society with a wide range of applications. The colloidal networks in these materials can exist in a mode of free settling when the network weight exceeds its compressive yield stress. An equivalent state occurs when the network is held fixed in place and used as a filter through which the suspending fluid is pumped. In either scenario, hydrodynamic instabilities leading to loss of network integrity occur. Experimental observations have shown that the loss of integrity is associated with the formation of eroded channels, so-called streamers, through which the fluid flows rapidly. However, the dynamics of growth and subsequent mechanism of collapse remain poorly understood. Here, a phenomenological model is presented that describes dynamically the radial growth of a streamer due to erosion of the network by rapid fluid back flow. The model exhibits a finite-time blowup – the onset of catastrophic failure in the gel – due to activated breaking of the inter-colloid bonds. Brownian dynamics simulations of hydrodynamically interacting and settling colloids in dilute gels are employed to examine the initiation and propagation of this instability, which are in good agreement with the theory. The model dynamics is also shown to accurately replicate measurements of streamer growth in two different experimental systems. The predictive capabilities and future improvements of the model are discussed and a stability-state diagram is presented providing insight into engineering strategies for avoiding settling instabilities in networks meant to have long shelf lives.
Gauge structures: From stabilizer codes to continuum models

Abstract Stabilizer codes are a powerful method for implementing fault-tolerant quantum memory and in the case of topological codes, they form useful models for topological phases of matter. In this paper, we discuss the theory of stabilizer codes as a discrete version of a linear gauge structure, a concept we introduce here. A linear gauge structure captures all the familiar ingredients of U ( 1 ) gauge theory including a generalization of charge conservation, Maxwell equations and topological terms. Using this connection, we prove some important results for stabilizer codes which can be used to characterize their error-correction properties. However, this perspective does not depend on any particular Hamiltonian or Lagrangian, which as a consequence is agnostic to the source of the gauge redundancy. Based upon the connection to stabilizer codes, we view the source of the gauge redundancy as an ambiguity in the tensor product structure of the Hilbert space. That is, the gauge provides a set of equivalent but arbitrary ways to factorize the Hilbert space. We apply this formalism to the d = 2 and 3 toric code as well as the paradigm fracton models, X-Cube and Haah’s cubic code. From this perspective, we are able to map all these models to some continuum version which captures all or some of the fractonic and topological features of their parent discrete models.
Bayesian neural networks at scale: a performance analysis and pruning study

Bayesian neural networks (BNNs) are a promising method of obtaining statistical uncertainties for neural network predictions but with a higher computational overhead which can limit their practical usage. This work explores the use of high-performance computing with distributed training to address the challenges of training BNNs at scale. We present a performance and scalability comparison of training the VGG-16 and Resnet-18 models on a Cray-XC40 cluster. We demonstrate that network pruning can speed up inference without accuracy loss and provide an open-source software package, BPrune, to automate this pruning. For certain models we find that pruning up to 80% of the network results in only a 7.0% loss in accuracy. With the development of new hardware accelerators for deep learning, BNNs are of considerable interest for benchmarking performance. This analysis of training a BNN at scale outlines the limitations and benefits compared to a conventional neural network.
Emergent Dark Matter, Baryon, and Lepton Numbers

We present a new mechanism for transferring a pre-existing lepton or baryon asymmetry to a dark matter asymmetry that relies on mass mixing which is dynamically induced in the early universe. Such mixing can succeed with only generic scales and operators and can give rise to distinctive relationships between the asymmetries in the two sectors. The mixing eliminates the need for the type of additional higher-dimensional operators that are inherent to many current asymmetric dark matter models. We consider several implementations of this idea. In one model, mass mixing is temporarily induced during a two-stage electroweak phase transition in a two Higgs doublet model. In the other class of models, mass mixing is induced by large field vacuum expectation values at high temperatures — either moduli fields or even more generic kinetic terms. Mass mixing models of this type can readily accommodate asymmetric dark matter masses ranging from 1 GeV to 100TeV and expand the scope of possible relationships between the dark and visible sectors in such models.
Chandra Identification of 26 New Black Hole Candidates in the Central Region of M31

We have previously identified 10 M31 black hole candidates (BHCs) in M31, from their X-ray properties alone. They exhibit “hard state” emission spectra that are seen at luminosities .10% Eddington in X-ray binaries (XBs) containing a neutron star (NS) or black hole (BH), at luminosities that significantly exceed the NS threshold. Nine of these are associated with globular clusters (GCs); hence, these are most likely low mass X-ray binaries (LMXBs); eight are included in this survey. We have recently discovered that analysis of the long term 0.5–4.5 keV variability of XBs via structure functions allows us to separate XBs from AGN, even though the emission spectra are often similar; this has enabled us to search for BHCs outside of GCs. We have identified 26 new BHCs (12 strong, 14 plausible) within 20 ′ of the M31 nucleus (M31*), using 152 Chandra observations spaced over ∼13 years; some of our classifications were enhanced with XMM-Newton observations. Of these, 7 appear within 100 ′′ of M31*; this supports the theory suggesting that this region experiences enhanced XB production via dynamical processes similar to those seen in GCs. We have found a parameter space where our black hole candidates are separated from Galactic neutron star binaries: we show that modelling a simulated hard state spectrum with a disk blackbody + blackbody model yields parameters that lie outside the space occupied by neutron star binaries that are modeled this way. The probability that our BHCs all lie within the NS parameter space is ∼ 3 × 10 −29 . Subject headings: x-rays: general — x-rays: binaries — black hole physics
Using deformable particles for single-particle measurements of velocity gradient tensors

We measure the deformation of particles made of several slender arms in a two-dimensional (2D) linear shear and a three-dimensional (3D) turbulent flow. We show how these measurements of arm deformations along with the rotation rate of the particle allow us to extract the velocity gradient tensor of the flow. The particles used in the experiments have three symmetric arms in a plane (triads) and are fabricated using 3D printing of a flexible polymeric material. Deformation measurements of a particle free to rotate about a fixed axis in a 2D simple shear flow are used to validate our model relating particle deformations to the fluid strain. We then examine deformable particles in a 3D turbulent flow created by a jet array in a vertical water tunnel. Particle orientations and deformations are measured with high precision using four high-speed cameras and have an uncertainty on the order of $$10^{-4}$$ radians. Measured deformations in 3D turbulence are small and only slightly larger than our orientation measurement uncertainty. Simulation results for triads in turbulence show deformations similar to the experimental observations. Deformable particles offer a promising method for measuring the full local velocity gradient tensor from measurements of a single particle where traditionally a high concentration of tracer particles would be required.
Chern–Simons and WZW anomaly cancelations across dimensions

Abstract The WZW functional in D = 4 can be derived directly from the Chern–Simons functional of a compactified D = 5 gauge theory and the boundary fermions it supplants. A simple pedagogical model based on U ( 1 ) gauge groups illustrates how this works. A bulk-boundary system with the fermions eliminated manifestly evinces anomaly cancelations between CS and WZW terms.
THE SPECTRAL EVOLUTION OF CONVECTIVE MIXING WHITE DWARFS, THE NON-DA GAP, AND WHITE DWARF COSMOCHRONOLOGY

The spectral distribution of field white dwarfs shows a feature called the "non-DA gap." As defined by Bergeron et al., this is a temperature range (5100-6100 K) where relatively few non-DA stars are found, even though such stars are abundant on either side of the gap. It is usually viewed as an indication that a significant fraction of white dwarfs switch their atmospheric compositions back and forth between hydrogen-rich and helium-rich as they cool. In this Letter, we present a Monte Carlo model of the Galactic disk white dwarf population, based on the spectral evolution model of Chen and Hansen. We find that the non-DA gap emerges naturally, even though our model only allows white dwarf atmospheres to evolve monotonically from hydrogen-rich to helium-rich through convective mixing. We conclude by discussing the effects of convective mixing on the white dwarf luminosity function and the use thereof for Cosmochronology.
Obscured Starburst Activity in High-redshift Clusters and Groups

Using Spitzer-Multiband Imaging Photometer 24 μm imaging and extensive Keck spectroscopy, we examine the nature of the obscured star-forming population in three clusters and three groups at z ~ 0.9. These six systems are the primary components of the Cl1604 supercluster, the largest structure imaged by Spitzer at redshifts approaching unity. We find that the average density of 24 μm detected galaxies within the Cl1604 clusters is nearly twice that of the surrounding field and that this overdensity scales with the cluster's dynamical state. The 24 μm bright members often appear optically unremarkable and exhibit only moderate [O II] line emission due to severe obscuration. Their spatial distribution suggests that they are an infalling population, but an examination of their spectral properties, morphologies, and optical colors indicates that they are not simply analogs of the field population that have yet to be quenched. Using stacked composite spectra, we find that the 24 μm detected cluster and group galaxies exhibit elevated levels of Balmer absorption compared with galaxies undergoing normal, continuous star formation. A similar excess is not observed in field galaxies with equivalent infrared luminosities, indicating a greater fraction of the detected cluster and group members have experienced a burst of star formation in the recent past compared to their counterparts in the field. Our results suggest that gas-rich galaxies at high redshift experience a temporary increase in their star formation activity as they assemble into denser environments. Using Hubble Space Telescope Advanced Camera for Surveys imaging, we find that disturbed morphologies are common among the 24 μm detected cluster and group members and become more prevalent in regions of higher galaxy density. We conclude that mergers are the dominant triggering mechanism responsible for the enhanced star formation found in the Cl1604 groups, while a mix of harassment and mergers are likely driving the activity of the cluster galaxies.
A May-type spectral sequence for higher topological Hochschild homology

Given a filtration of a commutative monoid A in a symmetric monoidal stable model category C , we construct a spectral sequence analogous to the May spectral sequence whose input is the higher order topological Hochschild homology of the associated graded commutative monoid of A , and whose output is the higher order topological Hochschild homology of A . We then construct examples of such filtrations and derive some consequences: for example, given a connective commutative graded ring R , we get an upper bound on the size of the THH –groups of E ∞ –ring spectra A such that π ∗ ( A ) ≅ R .
Limits of Calabi–Yau metrics when the Kähler class degenerates

We study the behavior of families of Ricci-flat Kahler metrics on a projective Calabi- Yau manifold when the Kahler classes degenerate to the boundary of the ample cone. We prove that if the limit class is big and nef the Ricci-flat metrics converge smoothly on compact sets outside a subvariety to a limit incomplete Ricci-flat metric. The limit can also be understood from algebraic geometry. Einstein metrics, namely metrics with constant Ricci curvature, have been an important subject of study in the field of differential geometry since the early days. The solution of the Calabi Conjecture given by Yau (Y1) in 1976 provided a very powerful existence theorem for Kahler-Einstein metrics with negative or zero Ricci curvature (the negative case was also done independently by Aubin (Au)). This produced a number of nonho- mogeneous examples of Ricci-flat manifolds. These spaces have been named Calabi-Yau manifolds by the physicists in the eighties, and have been thoroughly studied in several different areas of mathematics and physics. Prompted by the physical intuition of mirror symmetry, mathematicians have studied the ways in which Calabi-Yau manifolds can de- generate when they are moving in families. In general both the complex and symplectic (Kahler) structures are changing, and the behavior is not well understood. In this paper we will consider the case when the complex structure is fixed, and so we will be looking at a single compact projective Calabi-Yau manifold. The Kahler class is then allowed to vary inside the ample cone. As long as the class stays inside the cone, the corresponding Ricci-flat metrics vary smoothly, but they will degenerate when the class approaches the boundary of the cone. We will try to understand this degeneration process and see what the limiting space looks like. To introduce our results, let us fix some notation first. LetX be a compact projective Calabi-Yau manifold, of complex dimensionn. This is by definition a projective manifold
Continuous-time Gaussian process motion planning via probabilistic inference

We introduce a novel formulation of motion planning, for continuous-time trajectories, as probabilistic inference. We first show how smooth continuous-time trajectories can be represented by a smal...
Differential Privacy for Power Grid Obfuscation

The availability of high-fidelity energy networks brings significant value to academic and commercial research. However, such releases also raise fundamental concerns related to privacy and security as they can reveal sensitive commercial information and expose system vulnerabilities. This paper investigates how to release the data for power networks where the parameters of transmission lines and transformers are obfuscated . It does so by using the framework of Differential Privacy (DP), that provides strong privacy guarantees and has attracted significant attention in recent years. Unfortunately, simple DP mechanisms often result in AC-infeasible networks. To address these concerns, this paper presents a novel differentially private mechanism that guarantees AC-feasibility and largely preserves the fidelity of the obfuscated power network. Experimental results also show that the obfuscation significantly reduces the potential damage of an attack carried by exploiting the released dataset.
New exotic 4-manifolds via Luttinger surgery on Lefschetz fibrations

In [Small exotic 4-manifolds, Algebr. Geom. Topol.8 (2008) 1781–1794], the first author constructed the first known example of exotic minimal symplectic and minimal symplectic 4-manifold that is homeomorphic but not diffeomorphic to . The construction in [Small exotic 4-manifolds, Algebr. Geom. Topol.8 (2008) 1781–1794] uses Yukio Matsumoto's genus two Lefschetz fibrations on over &#x1d54a;2 along with the fake symplectic &#x1d54a;2 × &#x1d54a;2 construction given in [Construction of symplectic cohomology &#x1d54a;2 × &#x1d54a;2, Proc. Gokova Geom. Topol. Conf.14 (2007) 36–48]. The main goal in this paper is to generalize the construction in [Small exotic 4-manifolds, Algebr. Geom. Topol.8 (2008) 1781–1794] using the higher genus versions of Matsumoto's fibration constructed by Mustafa Korkmaz and Yusuf Gurtas on for any k ≥ 2 and n = 1, and k ≥ 1 and n ≥ 2, respectively. Using our symplectic building blocks, we also construct new symplectic 4-manifolds with the free group of rank s ≥ 1, the free product of the finite cyclic groups, and various other finitely generated groups as the fundamental group.
Diffusion of neutrinos in proto-neutron star matter with quarks

Abstract Neutrino opacities important in the evolution of a proto-neutron star containing quark matter are studied. The results for pure quark matter are compared with limiting expressions previously derived, and are generalized to the temperatures, neutrino degeneracies and lepton contents encountered in a proto-neutron star's evolution. We find that the appearance of quarks in baryonic matter drastically reduces the neutrino opacity for a given entropy, the reduction being sensitive to the thermodynamic conditions in the mixed quark–hadron phase.
A framework for covariate balance using Bregman distances

A common goal in observational research is to estimate marginal causal effects in the presence of confounding variables. One solution to this problem is to use the covariate distribution to weight the outcomes such that the data appear randomized. The propensity score is a natural quantity that arises in this setting. Propensity score weights have desirable asymptotic properties, but they often fail to adequately balance covariate data in finite samples. Empirical covariate balancing methods pose as an appealing alternative by exactly balancing the sample moments of the covariate distribution. With this objective in mind, we propose a framework for estimating balancing weights by solving a constrained convex program where the criterion function to be optimized is a Bregman distance. We then show that the different distances in this class render identical weights to those of other covariate balancing methods. A series of numerical studies are presented to demonstrate these similarities.
High-temperature asymptotics of supersymmetric partition functions

We study the supersymmetric partition function of 4d supersymmetric gauge theories with a U(1) R-symmetry on Euclidean S 3 × S 1 , with S 3 the unit-radius squashed three-sphere, and β the circumference of the circle. For superconformal theories, this partition function coincides (up to a Casimir energy factor) with the 4d superconformal index. The partition function can be computed exactly using the supersymmetric localization of the gauge theory path-integral. It takes the form of an elliptic hypergeometric integral, which may be viewed as a matrix-integral over the moduli space of the holonomies of the gauge fields around S 1 . At high temperatures (β → 0, corresponding to the hyperbolic limit of the elliptic hypergeometric integral) we obtain from the matrix-integral a quantum effective potential for the holonomies. The effective potential is proportional to the temperature. Therefore the high-temperature limit further localizes the matrix-integral to the locus of the minima of the potential. If the effective potential is positive semi-definite, the leading high-temperature asymptotics of the partition function is given by the formula of Di Pietro and Komargodski, and the subleading asymptotics is connected to the Coulomb branch dynamics on R 3 × S 1. In theories where the effective potential is not positive semi-definite, the Di Pietro-Komargodski formula needs to be modified. In particular, this modification occurs in the SU(2) theory of Intriligator-Seiberg-Shenker, and the SO(N ) theory of Brodie-Cho-Intriligator, both believed to exhibit “misleading” anomaly matchings, and both believed to yield interacting superconformal field theories with c < a. Two new simple tests for dualities between 4d supersymmetric gauge theories emerge as byproducts of our analysis.
Discrete Bethe–Sommerfeld Conjecture

In this paper, we prove a discrete version of the Bethe–Sommerfeld conjecture. Namely, we show that the spectra of multi-dimensional discrete periodic Schrodinger operators on $${\mathbb{Z}^d}$$ lattice with sufficiently small potentials contain at most two intervals. Moreover, the spectrum is a single interval, provided at least one of the periods is odd, and can have a gap whenever all periods are even.
TEMPERATURE-BASED METALLICITY MEASUREMENTS at z = 0.8: DIRECT CALIBRATION of STRONG-LINE DIAGNOSTICS at INTERMEDIATE REDSHIFT

Author(s): Jones, T; Martin, C; Cooper, MC | Abstract: We present the first direct calibration of strong-line metallicity diagnostics at significant cosmological distances using a sample at z ≃ 0.8 drawn from the DEEP2 Galaxy Redshift Survey. Oxygen and neon abundances are derived from measurements of electron temperature and density. We directly compare various commonly used relations between gas-phase metallicity and strong line ratios of O, Ne, and H at z ≃ 0.8 and z = 0. There is no evolution with redshift at high precision (δ log O H = -0.01 ± 0.03, D log Ne O = 0.01 ± 0.01). O, Ne, and H line ratios follow the same locus at z ≃ 0.8 as at z = 0, with ≲0.02 dex evolution and low scatter (≲0.04 dex). This suggests little or no evolution in physical conditions of H II regions at fixed oxygen abundance, in contrast to models which invoke more extreme properties at high redshifts. We speculate that offsets observed in the [N II]/Ha versus [O III]/Hβ diagram at high redshift are therefore due to [N II] emission, likely as a result of relatively high N/O abundance. If this is indeed the case, then nitrogen-based metallicity diagnostics suffer from systematic errors at high redshift. Our findings indicate that locally calibrated abundance diagnostics based on α-capture elements can be reliably applied at z ≃ 1 and possibly at much higher redshifts. This constitutes the first firm basis for the widespread use of empirical calibrations in high redshift metallicity studies.
PROSPECTS FOR MEASURING THE MASS OF BLACK HOLES AT HIGH REDSHIFTS WITH RESOLVED KINEMATICS USING GRAVITATIONAL LENSING

Application of the most robust method of measuring black hole masses, spatially resolved kinematics of gas and stars, is presently limited to nearby galaxies. The Atacama Large Millimeter/sub-millimeter Array (ALMA) and 30m class telescopes (the Thirty Meter Telescope, the Giant Magellan Telescope, and the European Extremely Large Telescope) with milli-arcsecond resolution are expected to extend such measurements to larger distances. Here, we study the possibility of exploiting the angular magnification provided by strong gravitational lensing to measure black hole masses at high redshifts (z ~ 1-6), using resolved gas kinematics with these instruments. We show that in ~15% and ~20% of strongly lensed galaxies, the inner 25 and 50 pc could be resolved, allowing the mass of 108 M ☉ black holes to be dynamically measured with ALMA, if moderately bright molecular gas is present at these small radii. Given the large number of strong lenses discovered in current millimeter surveys and future optical surveys, this fraction could constitute a statistically significant population for studying the evolution of the M-σ relation at high redshifts.
Center-to-Limb Variability of Hot Coronal EUV Emissions During Solar Flares

It is generally accepted that densities of quiet-Sun and active region plasma are sufficiently low to justify the optically thin approximation, and this is commonly used in the analysis of line emissions from plasma in the solar corona. However, the densities of solar flare loops are substantially higher, compromising the optically thin approximation. This study begins with a radiative transfer model that uses typical solar flare densities and geometries to show that hot coronal emission lines are not generally optically thin. Furthermore, the model demonstrates that the observed line intensity should exhibit center-to-limb variability (CTLV), with flares observed near the limb being dimmer than those occurring near disk center. The model predictions are validated with an analysis of over 200 flares observed by the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory (SDO), which uses six lines, with peak formation temperatures between 8.9 and 15.8 MK, to show that limb flares are systematically dimmer than disk-center flares. The data are then used to show that the electron column density along the line of sight typically increases by $1.76 \times 10^{19}~\mbox{cm}^{-2}$ for limb flares over the disk-center flare value. It is shown that the CTLV of hot coronal emissions reduces the amount of ionizing radiation propagating into the solar system, and it changes the relative intensities of lines and bands commonly used for spectral analysis.
Inhomogeneous Diophantine approximation of some Hurwitzian numbers

We continue the work of Takao Komatsu, and consider the inhomogeneous approximation constant L(θ,φ) for Hurwitzian θ and φ∈Q(θ)+Q. The current work uses a compactness theorem to relate such inhomogeneous constants to the homogeneous approximation constants. Among the new results are: a characterization of such pairs θ,φ for which L(θ,φ) = 0, consideration of small values of n2L(e2/s,φ) for φ = (rθ+m)/n, and the proof of a conjecture of Komatsu.
Hubble Space Telescope Imaging of the Active Dwarf Galaxy RGG 118

RGG 118 (SDSS 1523+1145) is a nearby ($z=0.0243$), dwarf disk galaxy ($M_{\ast}\approx2\times10^{9} M_{\odot}$) found to host an active $\sim50,000$ solar mass black hole at its core (Baldassare et al. 2015). RGG 118 is one of a growing collective sample of dwarf galaxies known to contain active galactic nuclei -- a group which, until recently, contained only a handful of objects. Here, we report on new \textit{Hubble Space Telescope} Wide Field Camera 3 UVIS and IR imaging of RGG 118, with the main goal of analyzing its structure. Using 2-D parametric modeling, we find that the morphology of RGG 118 is best described by an outer spiral disk, inner component consistent with a pseudobulge, and central PSF. The luminosity of the PSF is consistent with the central point source being dominated by the AGN. We measure the luminosity and mass of the "pseudobulge" and confirm that the central black hole in RGG 118 is under-massive with respect to the $M_{BH}-M_{\rm bulge}$ and $M_{BH}-L_{\rm bulge}$ relations. This result is consistent with a picture in which black holes in disk-dominated galaxies grow primarily through secular processes.
Diamond-kite adaptive quadrilateral meshing

We describe a family of quadrilateral meshes based on diamonds, rhombi with 60° and 120° angles, and kites with 60°, 90°, and 120° angles, that can be adapted to a local size function by local subdivision operations. Our meshes use a number of elements that is within a constant factor of the minimum possible for any mesh of bounded aspect ratio elements, graded by the same local size function, and is invariant under Laplacian smoothing. The vertices of our meshes form the centers of the circles in a pair of dual circle packings. The same vertex placement algorithm but a different mesh topology gives a pair of dual well-centered meshes adapted to the given size function.
On the reach of perturbative descriptions for dark matter displacement fields

We study Lagrangian Perturbation Theory (LPT) and its regularization in the Eective Field Theory (EFT) approach. We evaluate the LPT displacement with the same phases as a correspondingN-body simulation, which allows us to compare perturbation theory to the non-linear simulation with significantly reduced cosmic variance, and provides a more stringent test than simply comparing power spectra. We reliably detect a non-vanishing leading order EFT coecient and a stochastic displacement term, uncorrelated with the LPT terms. This stochastic term is expected in the EFT framework, and, to the best of our understanding, is not an artifact of numerical errors or transients in our simulations. This term constitutes a limit to the accuracy of perturbative descriptions of the displacement field and its phases, corresponding to a 1% error on the non-linear power spectrum atk = 0:2hMpc 1 at z = 0. Predicting the displacement power spectrum to higher accuracy or larger wavenumbers thus requires a model for the stochastic displacement.
Uniform dilations in higher dimensions

A theorem of Glasner says that if X is an infinite subset of the torus T, then for any > 0, there exists an integer n such that the dilation nX = {nx : x ∈ T} is -dense (i.e, it intersects any interval of length 2 in T). Alon and Peres provided a general framework for this problem, and showed quantitatively that one can restrict the dilation to be of the form f(n)X where f ∈ Z[x] is not constant. Building upon the work of Alon and Peres, we study this phenomenon in higher dimensions. Let A(x) be an L × N matrix whose entries are in Z[x], and X be an infinite subset of T . Contrarily to the case N = L = 1, it’s not always true that there is an integer n such that A(n)X is -dense in a translate of a subtorus of T. We give a necessary and sufficient condition for matrices A for which this is true. We also prove an effective version of the result.
Adaptive 3D convolutional neural network-based reconstruction method for 3D coherent diffraction imaging

We present a novel adaptive machine-learning based approach for reconstructing three-dimensional (3D) crystals from coherent diffraction imaging. We represent the crystals using spherical harmonics (SH) and generate the corresponding synthetic diffraction patterns. We utilize 3D convolutional neural networks (CNNs) to learn a mapping between 3D diffraction volumes and the SH, which describe the boundary of the physical volumes from which they were generated. We use the 3D CNN-predicted SH coefficients as the initial guesses, which are then fine-tuned using adaptive model-independent feedback for improved accuracy. We also adaptively tune the locations, intensities, and decay rates of collections of radial basis functions in order to reproduce the non-uniform internal structure of 3D objects and demonstrate the method for a synthetic volume that has an internal void and a density ramp.
Formal results regarding metric space techniques for the study of astrophysical maps

We extend a newly developed formal system for the description of astrophyscial maps. In this formalism, we consider the difference between maps to be the distance between elements of a pseudometric space (the space of all such maps). This Ansatz allows us to measure quantitatively the difference between any two maps and to order the space of all maps. For each physical characteristic of interest, this technique assigns an 'output' function to each map; the difference between the maps is then determined from the difference between their corresponding output functions. In this present study, we show that the results of this procedure are invariant under a class of transformations of the maps and the domains of the maps. In addition, we study the propagation of errors (observational uncertainties) through this formalism. We show that the uncertainties in the output functions can be controlled provided that the signal to noise ratios in the original astrophysical maps are sufficiently high. The results of this paper thus increase the effectiveness of this formal system for the description, classification, and analysis of astrophysical maps.
Heterogeneous quantum computing for satellite constellation optimization: solving the weighted k-clique problem

NP-hard optimization problems scale very rapidly with problem size, becoming unsolvable with brute force methods, even with supercomputing resources. Typically, such problems have been approximated with heuristics. However, these methods still take a long time and are not guaranteed to find an optimal solution. Quantum computing offers the possibility of producing significant speed-up and improved solution quality. Current quantum annealing (QA) devices are designed to solve difficult optimization problems, but they are limited by hardware size and qubit connectivity restrictions. We present a novel heterogeneous computing stack that combines QA and classical machine learning, allowing the use of QA on problems larger than the hardware limits of the quantum device. These results represent experiments on a real-world problem represented by the weighted k-clique problem. Through this experiment, we provide insight into the state of quantum machine learning.
Charge-pumping with finger capacitance in a custom electrostatic energy harvesting ASIC

We present an integrated circuit capable of scavenging energy from repetitive changes in finger touch capacitance. A finger tapping on this application-specific integrated circuit generates a capacitive change of approximately 770 pF. This change feeds into a charge-pump circuit that stores 320 pJ of energy on a 1 nF storage capacitor. We present measurement results and simulations that demonstrate operation. As a proof-of-concept, we also demonstrate that the harvested energy can power a ring oscillator that outputs a series of chirps with frequencies ranging from 80 Hz to 30 kHz as the storage capacitor voltage charges and discharges.
Flavour dynamics and CP violation in the SM*: A tale in five parts of great successes, little understanding and promise for the future!

Our knowledge of flavour dynamics has undergone a “quantum jump” since just before the turn of the millenium: direct CP violation has been firmly established in KL → ππ decays in 1999; the first CP asymmetry outside KL decays has been discovered in 2001 in Bd → ψKs, followed by Bd → π+π−, Bd → η'Ks and B → K±π±, the latter establishing direct CP violation also in the beauty sector. Furthermore CKM dynamics allows a description of CP insensitive and sensitive B, K and D transitions that is impressively consistent also on the quantitative level. Theories of flavour dynamics that could serve as alternatives to CKM have been ruled out. Yet these novel successes of the Standard Model (SM) do not invalidate any of the theoretical arguments for the incompleteness of the SM. In addition we have also more direct evidence for New Physics, namely neutrino oscillations, the observed baryon number of the Universe, dark matter and dark energy. While the New Physics anticipated at the TeV scale is not likely to shed any light on the SM’s mysteries of flavour, detailed and comprehensive studies of heavy flavour transitions will be essential in diagnosing salient features of that New Physics. Strategic principles for such studies will be outlined. These lectures delivered in 2005 have been updated in particular with respect to the discovery of % MathType!MTEF!2!1!+- % feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqr1ngB % PrgifHhDYfgasaacH8srps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr0x % c9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8fr % Fve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaacaWGcb % WaaSbaaSqaaiaadohaaeqaaOGaeyOeI0Yaa0aaaeaacaWGcbaaamaa % BaaaleaacaWGZbaabeaaaaa!3C89! $${B_s} - {\overline B _s}$$ and the strong evidence for % MathType!MTEF!2!1!+- % feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqr1ngB % PrgifHhDYfgasaacH8srps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr0x % c9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8fr % Fve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaacaWGeb % WaaWbaaSqabeaacaaIWaaaaOGaeyOeI0Yaa0aaaeaacaWGebaaamaa % CaaaleqabaGaaGimaaaaaaa!3C13! $${D^0} - {\overline D ^0}$$ oscillations.
A New Theoretical Framework for Curiosity for Learning in Social Contexts

Curiosity is a vital metacognitive skill in educational contexts. Yet, little is known about how social factors influence curiosity in group work. We argue that curiosity is evoked not only through individual, but also interpersonal activities, and present what we believe to be the first theoretical framework that articulates an integrated socio-cognitive account of curiosity based on literature spanning psychology, learning sciences and group dynamics, along with empirical observation of small-group science activity in an informal learning environment. We make a bipartite distinction between individual and interpersonal functions that contribute to curiosity, and multimodal behaviors that fulfill these functions. We validate the proposed framework by leveraging a longitudinal latent variable modeling approach. Findings confirm positive predictive relationship of the latent variables of individual and interpersonal functions on curiosity, with the interpersonal functions exercising a comparatively stronger influence. Prominent behavioral realizations of these functions are also discovered in a data-driven way. This framework is a step towards designing learning technologies that can recognize and evoke curiosity during learning in social contexts.
Finding Distant Galactic HII Regions

The WISE Catalog of Galactic HII Regions contains ∼ 2000 HII region candidates lacking ionized gas spectroscopic observations. All candidates have the characteristic HII region mid-infrared morphology of WISE 12µm emission surrounding 22µm emission, and additionally have detected radio continuum emission. We here report Green Bank Telescope (GBT) hydrogen radio recombination line (RRL) and radio continuum detections at X-band (9GHz; 3cm) of 302 WISE HII region candidates (out of 324 targets observed) in the zone 225 ◦ ≥ l ≥ −20 ◦ , |b | ≤ 6 ◦ . Here we extend the sky coverage of our HII region Discovery Survey (HRDS), which now contains nearly 800 HII regions distributed across the entire northern sky. We provide LSR velocities for the 302 detections and kinematic distances for 131 of these. Of the 302 new detections, five have (l,b,v) coordinates consistent with the Outer Scutum-Centaurus Arm (OSC), the most distant molecular spiral arm of the Milky Way. Due to the Galactic warp, these nebulae are found at Galactic latitudes > 1 ◦ in the first Galactic quadrant, and therefore were missed in previous surveys of the Galactic plane. One additional region has a longitude and velocity consistent with the OSC but lies at a negative Galactic latitude (G039.183−01.422; −54.9 kms −1 ). With Heliocentric distances > 22kpc and Galactocentric distances > 16kpc, the OSC HII regions are the most distant known in the Galaxy. We detect an additional three HII regions near l ≃ 150 ◦ whose LSR velocities place them at Galactocentric radii > 19kpc. If their distances are correct, these nebulae may represent the limit to Galactic massive star formation.
Coding of geodesics on some modular surfaces and applications to odd and even continued fractions

Abstract The connection between geodesics on the modular surface PSL ( 2 , Z ) ∖ H and regular continued fractions, established by Series, is extended to a connection between geodesics on Γ ∖ H and odd and grotesque continued fractions, where Γ ≅ Z 3 ∗ Z 3 is the index two subgroup of PSL ( 2 , Z ) generated by the order three elements 0 − 1 1 1 and 0 1 − 1 1 , and having an ideal quadrilateral as fundamental domain.A similar connection between geodesics on Θ ∖ H and even continued fractions is discussed in our framework, where Θ denotes the Theta subgroup of PSL ( 2 , Z ) generated by 0 − 1 1 0 and 1 2 0 1 .