Results for "Tyler D. Robinson"

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A Theory of Exoplanet Transits with Light ScatteringJan 19 2017Oct 24 2018Exoplanet transit spectroscopy enables the characterization of distant worlds, and will yield key results for NASA's James Webb Space Telescope. However, transit spectra models are often simplified, omitting potentially important processes like refraction ... More
Common 0.1 bar Tropopause in Thick Atmospheres Set by Pressure-Dependent Infrared TransparencyDec 24 2013A minimum atmospheric temperature, or tropopause, occurs at a pressure of around 0.1 bar in the atmospheres of Earth, Titan, Jupiter, Saturn, Uranus and Neptune, despite great differences in atmospheric composition, gravity, internal heat and sunlight. ... More
Stability of CO2 Atmospheres on Desiccated M Dwarf ExoplanetsJan 27 2015May 20 2015We investigate the chemical stability of CO2-dominated atmospheres of desiccated M dwarf terrestrial exoplanets using a 1-dimensional photochemical model. Around Sun-like stars, CO2 photolysis by Far-UV (FUV) radiation is balanced by recombination reactions ... More
Sulfur Hazes in Giant Exoplanet Atmospheres: Impacts on Reflected Light SpectraJan 02 2017Feb 25 2017Recent work has shown that sulfur hazes may arise in the atmospheres of some giant exoplanets due to the photolysis of H$_{2}$S. We investigate the impact such a haze would have on an exoplanet's geometric albedo spectrum and how it may affect the direct ... More
Is the Pale Blue Dot unique? Optimized photometric bands for identifying Earth-like exoplanetsDec 01 2015Jan 29 2016The next generation of ground and space-based telescopes will image habitable planets around nearby stars. A growing literature describes how to characterize such planets with spectroscopy, but less consideration has been given to the usefulness of planet ... More
Influence of Chemisorbed Oxygen on the Growth of Graphene on Cu(100) by Chemical Vapor DepositionMar 14 2014Understanding the influence that copper substrate surface symmetry and oxygen impurities have on the growth of graphene by chemical vapor deposition is important for developing techniques for producing high quality graphene. Therefore, we have studied ... More
Pale Orange Dots: The Impact of Organic Haze on the Habitability and Detectability of Earthlike ExoplanetsFeb 09 2017Hazes are common in known planet atmospheres, and geochemical evidence suggests early Earth occasionally supported an organic haze with significant environmental and spectral consequences. The UV spectrum of the parent star drives organic haze formation ... More
The Center of Light: Spectroastrometric Detection of ExomoonsSep 04 2015Direct imaging of extrasolar planets with future space-based coronagraphic telescopes may provide a means of detecting companion moons at wavelengths where the moon outshines the planet. We propose a detection strategy based on the positional variation ... More
On the Identification of High Mass Star Forming Regions using IRAS: Contamination by Low-Mass ProtostarsApr 22 2005We present the results of a survey of a small sample (14) of low-mass protostars (L_IR < 10^3 Lsun) for 6.7 GHz methanol maser emission performed using the ATNF Parkes radio telescope. No new masers were discovered. We find that the lower luminosity limit ... More
Generalized forms and gravitationDec 03 2013The algebra and calculus of generalized differential forms are reviewed and employed to construct a class of generalized connections and to investigate their properties. The class includes generalized connections which are flat when Einstein's vacuum ... More
Generalized Chern-Simons action principles for gravityJun 30 2015Generalized differential forms are employed to construct generalized connections. Lorentzian four-metrics determined by certain of these connections satisfy Einstein's vacuum field equations when the connections are flat. Generalized Chern-Simons action ... More
Characterizing Exoplanet HabitabilityJan 18 2017Nov 21 2017A habitable exoplanet is a world that can maintain stable liquid water on its surface. Techniques and approaches to characterizing such worlds are essential, as performing a census of Earth-like planets that may or may not have life will inform our understanding ... More
Modeling the Infrared Spectrum of the Earth-Moon System: Implications for the Detection and Characterization of Earthlike Extrasolar Planets and their Moonlike CompanionsOct 17 2011Large surface temperatures on the illuminated hemisphere of the Moon can lead it to contribute a significant amount of flux to spatially unresolved infrared (IR) observations of the Earth-Moon system, especially at wavelengths where Earth's atmosphere ... More
Completely Colorblind: Advances in Gray Techniques and Applications to Planets Near and FarNov 10 2015Gray models, which replace spectrally-resolved opacities with a wavelength independent mean opacity, are currently seeing wide and diverse application. In this brief review, we discuss both the history of gray techniques as well as recent applications ... More
Habitable zone predictions and how to test themMar 09 2019Mar 12 2019The habitable zone (HZ) is the region around a star(s) where standing bodies of water could exist on the surface of a rocky planet. The classical HZ definition makes a number of assumptions common to the Earth, including assuming that the most important ... More
Observing the Atmospheres of Known Temperate Earth-sized Planets with JWSTAug 14 2017Nov 29 2017Nine transiting Earth-sized planets have recently been discovered around nearby late M dwarfs, including the TRAPPIST-1 planets and two planets discovered by the MEarth survey, GJ 1132b and LHS 1140b. These planets are the smallest known planets that ... More
An intermediate value theorem for sequences with terms in a finite setSep 23 2005We prove an intermediate value theorem of an arithmetical flavor, involving the consecutive averages of sequences with terms in a given finite set A. For every such set we completely characterize the numbers x ("intermediate values") with the property ... More
Linearized Flux Evolution (LiFE): A Technique for Rapidly Adapting Fluxes from Full-Physics Radiative Transfer ModelsMar 06 2018Solar and thermal radiation are critical aspects of planetary climate, with gradients in radiative energy fluxes driving heating and cooling. Climate models require that radiative transfer tools be versatile, computationally efficient, and accurate. Here, ... More
Kalman filtering techniques for focal plane electric field estimationJan 16 2013For a coronagraph to detect faint exoplanets, it will require focal plane wavefront control techniques to continue reaching smaller angular separations and higher contrast levels. These correction algorithms are iterative and the control methods need ... More
Kalman Filter Estimation for Focal Plane Wavefront CorrectionAug 16 2012Space-based coronagraphs for future earth-like planet detection will require focal plane wavefront control techniques to achieve the necessary contrast levels. These correction algorithms are iterative and the control methods require an estimate of the ... More
A Simple Model for Radiative and Convective Fluxes in Planetary AtmospheresAug 01 2018One-dimensional (vertical) models of planetary atmospheres typically balance the net solar and internal energy fluxes against the net thermal radiative and convective heat fluxes to determine an equilibrium thermal structure. Thus,simple models of shortwave ... More
Temperature Fluctuations as a Source of Brown Dwarf VariabilityMar 10 2014Apr 23 2014A number of brown dwarfs are now known to be variable with observed amplitudes as large as 10-30% at some wavelengths. While spatial inhomogeneities in cloud coverage and thickness are likely responsible for much of the observed variability, it is possible ... More
Earth as an ExoplanetApr 11 2018The search for habitable and inhabited environments beyond our planet commonly focuses on analogs to Earth, especially in the case of exoplanets. Observations from ground-based facilities, satellites, and spacecraft have yielded a rich collection of data ... More
On the Cool Side: Modeling the Atmospheres of Brown Dwarfs and Giant PlanetsOct 23 2014The atmosphere of a brown dwarf or extrasolar giant planet controls the spectrum of radiation emitted by the object and regulates its cooling over time. While the study of these atmospheres has been informed by decades of experience modeling stellar and ... More
An Analytic Radiative-Convective Model for Planetary AtmospheresSep 09 2012We present an analytic 1-D radiative-convective model of the thermal structure of planetary atmospheres. Our model assumes that thermal radiative transfer is gray and can be represented by the two-stream approximation. Model atmospheres are assumed to ... More
Efficiently Computing Piecewise Flat Embeddings for Data Clustering and Image SegmentationDec 20 2016Image segmentation is a popular area of research in computer vision that has many applications in automated image processing. A recent technique called piecewise flat embeddings (PFE) has been proposed for use in image segmentation; PFE transforms image ... More
Memory Efficient Experience Replay for Streaming LearningSep 16 2018Feb 23 2019In supervised machine learning, an agent is typically trained once and then deployed. While this works well for static settings, robots often operate in changing environments and must quickly learn new things from data streams. In this paradigm, known ... More
Implementing the three-particle quantization condition including higher partial wavesJan 21 2019Mar 04 2019We present an implementation of the relativistic three-particle quantization condition including both $s$- and $d$-wave two-particle channels. For this, we develop a systematic expansion about threshold of the three-particle divergence-free K matrix, ... More
WFPC2 aperture photometry and PSF modellingMar 22 1995Since the WFPC-2 undersamples the PSF, aperture photometry can produce results which are competetive with profile fitting in many situations. This article reports and investigation of aperture corrections using both real data and PSF models.
Support Vector Machine Application for Multiphase Flow Pattern PredictionJun 12 2018In this paper a data analytical approach featuring support vector machines (SVM) is employed to train a predictive model over an experimentaldataset, which consists of the most relevant studies for two-phase flow pattern prediction. The database for this ... More
Maximizing the ExoEarth Candidate Yield from a Future Direct Imaging MissionSep 17 2014Oct 28 2014ExoEarth yield is a critical science metric for future exoplanet imaging missions. Here we estimate exoEarth candidate yield using single visit completeness for a variety of mission design and astrophysical parameters. We review the methods used in previous ... More
Multi-Switch: a Tool for Finding Potential Edge-Disjoint $1$-factorsAug 01 2015Let $n$ be even, let $\pi = (d_1, \ldots, d_n)$ be a graphic degree sequence, and let $\pi - k = (d_1 - k, \ldots, d_n - k)$ also be graphic. Kundu proved that $\pi$ has a realization $G$ containing a $k$-factor, or $k$-regular graph. Another way to state ... More
A generalization of Vassiliev's planarity criterionOct 04 2012Motivated by his studies in knot theory V. Vassiliev introduced $X$-graphs as regular 4-valent graph with a structure of pairs of opposite edges at each vertex. He conjectured the conditions under which $X$-graph can be embedded into a plane respecting ... More
Analytic Scattering and Refraction Models for Exoplanet Transit SpectraNov 03 2017Observations of exoplanet transit spectra are essential to understanding the physics and chemistry of distant worlds. The effects of opacity sources and many physical processes combine to set the shape of a transit spectrum. Two such key processes - refraction ... More
Characterizing Rocky and Gaseous Exoplanets with 2-meter Class Space-based CoronagraphsJul 02 2015Nov 12 2015Several concepts now exist for small, space-based missions to directly characterize exoplanets in reflected light. Here, we develop an instrument noise model suitable for studying the spectral characterization potential of a coronagraph-equipped, space-based ... More
Detecting Oceans on Extrasolar Planets Using the Glint EffectAug 23 2010Glint, the specular reflection of sunlight off Earth's oceans, may reveal the presence of oceans on an extrasolar planet. As an Earth-like planet nears crescent phases, the size of the ocean glint spot increases relative to the fraction of illuminated ... More
A Statistical Comparative Planetology Approach to Maximize the Scientific Return of Future Exoplanet Characterization EffortsMar 12 2019Provided that sufficient resources are deployed, we can look forward to an extraordinary future in which we will characterize potentially habitable planets. Until now, we have had to base interpretations of observations on habitability hypotheses that ... More
Non-abelian convexity of based loop groupsSep 17 2015If $K$ is a compact, connected, simply connected Lie group, its based loop group $\Omega K$ is endowed with a Hamiltonian $S^1 \times T$ action, where $T$ is a maximal torus of $K$. Atiyah and Pressley examined the image of $\Omega K$ under the moment ... More
Dimensional reduction for generalized continuum polymersMay 30 2016The Brydges-Imbrie dimensional reduction formula relates the pressure of a $d$-dimensional gas of hard spheres to a model of $(d+2)$-dimensional branched polymers. Brydges and Imbrie's proof was non-constructive and relied on a supersymmetric localization ... More
From pQCD to neutron stars: matching equations of state to constrain global star propertiesAug 15 2016The equation of state (EoS) of quantum chromodynamics (QCD) at zero temperature can be calculated in two different perturbative regimes: for small values of the baryon chemical potential $\mu$, one may use chiral perturbation theory (ChEFT); and for large ... More
The Information Theoretically Efficient Model (ITEM): A model for computerized analysis of large datasetsSep 22 2014Nov 04 2014This document discusses the Information Theoretically Efficient Model (ITEM), a computerized system to generate an information theoretically efficient multinomial logistic regression from a general dataset. More specifically, this model is designed to ... More
Higher configuration operads by way of quiver GrassmanniansNov 19 2012We introduce a construction that associates, to each finite dimensional k-vector space V, a family of projective k-varieties that comes equipped with the structure of a operad in the category of k-schemes. When dim V = 1, this operad contains, as a suboperad, ... More
A note on the eigenvalues of double band matricesOct 31 2008We consider matrices containing two diagonal bands of positive entries. We show that all eigenvalues of such matrices are of the form $r \zeta$, where $r$ is a nonnegative real number and $\zeta$ is a $p$th root of unity, where $p$ is the period of the ... More
Every AF-algebra is Morita equivalent to a graph algebraOct 27 2003We show how to modify any Bratteli diagram $E$ for an AF-algebra $A$ to obtain a Bratteli diagram $KE$ for $A$ whose graph algebra $C^*(KE)$ contains both $A$ and $C^*(E)$ as full corners.
Particle Dark Matter Constraints from the Draco Dwarf GalaxyMar 15 2002It is widely thought that neutralinos, the lightest supersymmetric particles, could comprise most of the dark matter. If so, then dark halos will emit radio and gamma ray signals initiated by neutralino annihilation. A particularly promising place to ... More
Stretching and Rotation Sets of Quasiconformal MappingsOct 12 2017Quasiconformal maps in the plane are orientation preserving homeomorphisms that satisfy certain distortion inequalities; infinitesimally, they map circles to ellipses of bounded eccentricity. Such maps have many useful geometric distortion properties, ... More
Galois actions on analytifications and tropicalizationsMar 22 2017Mar 30 2017This paper initiates a research program that seeks to recover algebro-geometric Galois representations from combinatorial data. We study tropicalizations equipped with symmetries coming from the Galois-action present on the lattice of $1$-parameter subgroups ... More
Geometric Bounds for Favard LengthNov 27 2017Given a set in the plane, the average length of its projections over all directions is called Favard length. This quantity measures the size of a set, and is closely related to metric and geometric properties of the set such as rectifiability, Hausdorff ... More
Reprogrammable Electro-Optic Nonlinear Activation Functions for Optical Neural NetworksMar 12 2019We introduce an electro-optic hardware platform for nonlinear activation functions in optical neural networks. The optical-to-optical nonlinearity operates by converting a small portion of the input optical signal into an analog electric signal, which ... More
Measuring chromatic aberrations in imaging systems using plasmonic nano-particlesAug 04 2015Chromatic aberration in optical systems arises from the wavelength dependence of a glass's refractive index. Polychromatic rays incident upon an optical surface are refracted at slightly different angles and in traversing an optical system follow distinct ... More
Progress report on the relativistic three-particle quantization conditionOct 15 2018We describe recent work on the relativistic three-particle quantization condition, generalizing and applying the original formalism of Hansen and Sharpe, and of Brice\~no, Hansen and Sharpe. In particular, we sketch three recent developments: the generalization ... More
X-ray and IR Point Source Identification and Characteristics In the Embedded, Massive Star-Forming Region RCW 38May 03 2006We report on results of a 96.7 ks Chandra observation of one of the youngest, most embedded and massive young stellar clusters studied in X-rays - RCW 38. We detect 460 sources in the field of which 360 are confirmed to be associated with the RCW~38 cluster. ... More
X-ray and IR Point Source Identification and Characteristics in the Embedded, Massive Star-Forming Region RCW 108Dec 18 2007We report on the results of an approximately 90 ks Chandra observation of a complex region that hosts multiple sites of recent and active star formation in ARA OB1a. The field is centered on the embedded cluster RCW 108-IR and includes and a large portion ... More
Seyferts on the edge: polar scattering and orientation-dependent polarization in Seyfert 1 nucleiJan 23 2004We have identified 12 Seyfert 1 galaxies that exhibit optical polarization spectra similar to those of Seyfert 2 galaxies in which polarized broad-lines are detected. We present new spectropolarimetric observations of 3 of them: Was 45, Mrk 231 and NGC ... More
An asymptotic-numerical approach for examining global solutions to an ordinary differential equationSep 28 2007Purely numerical methods do not always provide an accurate way to find all the global solutions to nonlinear ODE on infinite intervals. For example, finite-difference methods fail to capture the asymptotic behavior of solutions, which might be critical ... More
A sheaf-theoretic perspective on samplingMay 01 2014Sampling theory has traditionally drawn tools from functional and complex analysis. Past successes, such as the Shannon-Nyquist theorem and recent advances in frame theory, have relied heavily on the application of geometry and analysis. The reliance ... More
Partition complexes, duality and integral tree representationsOct 26 2004We show that the poset of non-trivial partitions of 1,2,...,n has a fundamental homology class with coefficients in a Lie superalgebra. Homological duality then rapidly yields a range of known results concerning the integral representations of the symmetric ... More
A Topological Lowpass Filter for Quasiperiodic SignalsJun 28 2016This article presents a two-stage topological algorithm for recovering an estimate of a quasiperiodic function from a set of noisy measurements. The first stage of the algorithm is a topological phase estimator, which detects the quasiperiodic structure ... More
Analyzing wireless communication network vulnerability with homological invariantsNov 06 2013This article explains how sheaves and homology theory can be applied to simplicial complex models of wireless communication networks to study their vulnerability to jamming. It develops two classes of invariants (one local and one global) for studying ... More
The Nyquist theorem for cellular sheavesJul 27 2013We develop a unified sampling theory based on sheaves and show that the Shannon-Nyquist theorem is a cohomological consequence of an exact sequence of sheaves. Our theory indicates that there are additional cohomological obstructions for higher-dimensional ... More
Instability of an equilibrium with negative definite linearizationFeb 19 2007Feb 20 2007A nonlinear parabolic differential equation is presented which has at least one equilibrium. This equilibrium is shown to have a negative definite linearization, but a spectrum which includes zero. An elementary construction shows that the equilibrium ... More
Instability of an equilibrium of a partial differential equationApr 30 2007Sep 09 2007A nonlinear parabolic differential equation with a quadratic nonlinearity is presented which has at least one equilibrium. The linearization about this equilibrium is asymptotically stable, but by using a technique inspired by H. Fujita, we show that ... More
Ultrafast THz Faraday Rotation in GrapheneOct 28 2014Terahertz (THz) Faraday rotation measurements were performed to investigate carrier dynamics in p-type CVD graphene. We used static and time-resolved polarization-sensitive THz transmission measurements in a magnetic field to probe free carriers in GaAs, ... More
Sheaf and cosheaf methods for analyzing multi-model systemsApr 15 2016There is an interplay between models, specified by variables and equations, and their connections to one another. This dichotomy should be reflected in the abstract as well. Without referring to the models directly -- only that a model consists of spaces ... More
Cohomology of diagrams of algebrasFeb 25 2008We consider cohomology of diagrams of algebras by Beck's approach, using comonads. We then apply this theory to computing the cohomology of $\Psi$-rings. Our main result is that there is a spectral sequence connecting the cohomology of the diagram of ... More
Projective Decomposition and Matrix Equivalence up to ScaleJan 04 2019A data matrix may be seen simply as a means of organizing observations into rows ( e.g., by measured object) and into columns ( e.g., by measured variable) so that the observations can be analyzed with mathematical tools. As a mathematical object, a matrix ... More
Higher order commutator estimates and local existence for the non-resistive MHD equations and related modelsJan 20 2014This paper establishes the local-in-time existence and uniqueness of strong solutions in $H^{s}$ for $s > n/2$ to the viscous, non-resistive magnetohydrodynamics (MHD) equations in $\mathbb{R}^{n}$, $n=2, 3$, as well as for a related model where the advection ... More
Abiotic Ozone and Oxygen in Atmospheres Similar to Prebiotic EarthJul 09 2014The search for life on planets outside our solar system will use spectroscopic identification of atmospheric biosignatures. The most robust remotely-detectable potential biosignature is considered to be the detection of oxygen (O_2) or ozone (O_3) simultaneous ... More
Compression of structured high-throughput sequencing dataNov 28 2012Large biological datasets are being produced at a rapid pace and create substantial storage challenges, particularly in the domain of high-throughput sequencing (HTS). Most approaches currently used to store HTS data are either unable to quickly adapt ... More
Deep Learning as a Tool to Predict Flow Patterns in Two-Phase FlowMay 19 2017In order to better model complex real-world data such as multiphase flow, one approach is to develop pattern recognition techniques and robust features that capture the relevant information. In this paper, we use deep learning methods, and in particular ... More
Spectrum-driven Planetary Deglaciation Due to Increases in Stellar LuminosityMar 14 2014Distant planets in globally ice-covered, "snowball", states may depend on increases in their host stars' luminosity to become hospitable for surface life. Using a General Circulation Model (GCM), we simulated the equilibrium climate response of a planet ... More
Detecting and Constraining N$_2$ Abundances in Planetary Atmospheres Using Collisional PairsJul 28 2015Characterizing the bulk atmosphere of a terrestrial planet is important for determining surface pressure and potential habitability. Molecular nitrogen (N$_2$) constitutes the largest fraction of Earth$'$s atmosphere and is likely to be a major constituent ... More
The Picard Group of the Moduli of Higher Spin CurvesAug 16 1999Aug 23 1999This article treats the Picard group of the moduli (stack) of r-spin curves and its compactification. Generalized spin curves, or r-spin curves are a natural generalization of 2-spin curves (algebraic curves with a theta-characteristic), and have been ... More
Titan solar occultation observations reveal transit spectra of a hazy worldJun 12 2014Oct 08 2014High altitude clouds and hazes are integral to understanding exoplanet observations, and are proposed to explain observed featureless transit spectra. However, it is difficult to make inferences from these data because of the need to disentangle effects ... More
Warming early Mars with CO2 and H2May 26 2014The presence of valleys on ancient terrains of Mars suggest that liquid water flowed on the martian surface 3.8 billion years ago or before. The above-freezing temperatures required to explain valley formation could have been transient, in response to ... More
Topological automorphic forms on U(1,1)Jan 13 2009Oct 04 2009The homotopy type and homotopy groups of some spectra TAF of topological automorphic forms associated to a unitary similitude group GU of type (1,1) are explicitly described in quasi-split cases. The spectrum TAF is shown to be closely related to the ... More
Topological automorphic formsFeb 23 2007Dec 11 2008We apply a theorem of J. Lurie to produce cohomology theories associated to certain Shimura varieties of type U(1,n-1). These cohomology theories of topological automorphic forms (TAF) are related to Shimura varieties in the same way that TMF is related ... More
Generalized Equivariant Cohomology and StratificationsOct 15 2014Dec 20 2014For $T$ a compact torus and $E_T^*$ a generalized $T$-equivariant cohomology theory, we provide a systematic framework for computing $E_T^*$ in the context of equivariantly stratified smooth complex projective varieties. This allows us to explicitly compute ... More
Multiple-particle interaction in $1+1$ dimensional lattice modelAug 22 2018Finite volume multiple-particle interaction is studied in a two-dimensional complex $\phi^4$ lattice model. The existence of analytical solutions to the $\phi^4$ model in two-dimensional space and time makes it a perfect model for the numerical study ... More
Critical points of master functions and mKdV hierarchy of type $C^{(1)}_{n}$Nov 03 2018We consider the population of critical points, generated from the critical point of the master function with no variables, which is associated with the trivial representation of the twisted affine Lie algebra $C_n^{(1)}$. The population is naturally partitioned ... More
Primes in short intervals on curves over finite fieldsJan 24 2017Mar 31 2018We prove an analogue of the Prime Number Theorem for short intervals on a smooth projective geometrically irreducible curve of arbitrary genus over a finite field. A short interval "of size E" in this setting is any additive translate of the space of ... More
Embeddings of *-graphs into 2-surfacesDec 22 2012This paper considers *-graphs in which all vertices have degree 4 or 6, and studies the question of calculating the genus of orientable 2-surfaces into which such graphs may be embedded. A *-graph is a graph endowed with a formal adjacency structure on ... More
LightRel SemEval-2018 Task 7: Lightweight and Fast Relation ClassificationApr 19 2018We present LightRel, a lightweight and fast relation classifier. Our goal is to develop a high baseline for different relation extraction tasks. By defining only very few data-internal, word-level features and external knowledge sources in the form of ... More
Critical points of master functions and mKdV hierarchy of type $A^{(2)}_{2n}$Feb 20 2017We consider the population of critical points generated from the critical point of the master function with no variables, which is associated with the trivial representation of the twisted affine Lie algebra $A^{(2)}_{2n}$. The population is naturally ... More
Discrete Variational AutoencodersSep 07 2016Apr 22 2017Probabilistic models with discrete latent variables naturally capture datasets composed of discrete classes. However, they are difficult to train efficiently, since backpropagation through discrete variables is generally not possible. We present a novel ... More
The equation of state in two-, three-, and four-color QCD at non-zero temperature and densityDec 21 2014We calculate the equation of state at non-zero temperature and density from first principles in two-, three- and four-color QCD with two fermion flavors in the fundamental and two-index, antisymmetric representation. By matching low-energy results (from ... More
Perturbative and Non-Perturbative Origins of the Proton SeaSep 01 2011Deep Inelastic Scattering and Drell-Yan experiments have measured a light flavor asymmetry in the proton sea. The excess of dbar over ubar quarks can be understood in many models, but the ratio dbar(x)/ubar(x) measured by Fermilab E866 has not been successfully ... More
Fast, Robust and Non-convex Subspace RecoveryJun 24 2014Jun 09 2016This work presents a fast and non-convex algorithm for robust subspace recovery. The data sets considered include inliers drawn around a low-dimensional subspace of a higher dimensional ambient space, and a possibly large portion of outliers that do not ... More
Asymptotics of determinants of discrete Schrödinger operatorsSep 14 2016Sep 16 2016We consider the asymptotics of the determinants of large discrete Schr\"odinger operators, i.e. "discrete Laplacian $+$ diagonal": \[T_n(f) = -[\delta_{j,j+1}+\delta_{j+1,j}] + \mbox{diag}\left(f\left(\frac{1}{n}\right), f\left(\frac{2}{n}\right),\dots, ... More
Trimmed Serendipity Finite Element Differential FormsJul 03 2016Jan 05 2018We introduce the family of trimmed serendipity finite element differential form spaces, defined on cubical meshes in any number of dimensions, for any polynomial degree, and for any form order. The relation between the trimmed serendipity family and the ... More
Modeling the Infrared Emission in Cygnus AJan 16 2012We present new Spitzer IRS spectroscopy of Cygnus A, one of the most luminous radio sources in the local universe. Data on the inner 20" are combined with new reductions of MIPS and IRAC photometry as well as data from the literature to form a radio through ... More
The Critical, Strategic Importance of Adaptive Optics-Assisted Ground-Based Telescopes for the Success of Future NASA Exoplanet Direct Imaging MissionsMar 11 2019Ground-based telescopes coupled with adaptive optics (AO) have been playing a leading role in exoplanet direct imaging science and technological development for the past two decades and will continue to have an indispensable role for the next decade and ... More
Detection of Ocean Glint and Ozone Absorption Using LCROSS Earth ObservationsMay 18 2014The Lunar CRater Observation and Sensing Satellite (LCROSS) observed the distant Earth on three occasions in 2009. These data span a range of phase angles, including a rare crescent phase view. For each epoch, the satellite acquired near-infrared and ... More
On the structure of subsets of an orderable group with some small doubling propertiesMay 03 2015The aim of this paper is to present a complete description of the structure of subsets S of an orderable group G satisfying |S^2| = 3|S|-2 and <S> is non-abelian.
Unveiling the Important Role of Groups in the Evolution of Massive Galaxies: Insights from an Infrared Passive Sequence at Intermediate RedshiftFeb 18 2008The most massive galaxies in the Universe are also the oldest. To overturn this apparent contradiction with hierarchical growth models, we focus on the group scale haloes which host most of these galaxies. A stellar mass selected M_* >~ 2x10^10M_sol sample ... More
Evolved Climates and Observational Discriminants for the TRAPPIST-1 Planetary SystemSep 20 2018The TRAPPIST-1 planetary system provides an unprecedented opportunity to study terrestrial exoplanet evolution with the James Webb Space Telescope (JWST) and ground-based observatories. Since M dwarf planets likely experience extreme volatile loss, the ... More
Distributive QuotientsSep 03 2014We note that each lattice $L$ has a unique largest distributive quotient, of which every distributive quotient of $L$ is itself a quotient.
Beyond Quartic HamiltoniansApr 19 2016We investigate the Hamiltonian system generated by a homogeneous binary polynomial $U$ of order greater than four. In particular, we study the circumstances under which the associated Hessian is a Weierstrass $\wp$ function and find that the vanishing ... More
Fredholm theory for cofinite setsSep 27 2015We investigate two ways in which self-maps of an infinite set may be close to bijections; our investigation generates a $\mathbb{Z}$-valued index theory and a corresponding extension by $\mathbb{Z}$ for the quotient of the full symmetric group by its ... More
The Elliptic Functions in a First-Order SystemMar 17 2019We investigate the first-order system `$s\,' = c^3, \, c\,' = - s^3; \, s(0) = 0, \, c(0) = 1$'. Its solutions have the property that $s \, c$, $s^2$ and $c^2$ extend to simply-poled elliptic functions, which we explicitly identify in terms of the lemniscatic ... More