Results for "Ethan C. Jackson"

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Novelty Search for Deep Reinforcement Learning Policy Network Weights by Action Sequence Edit Metric DistanceFeb 08 2019Reinforcement learning (RL) problems often feature deceptive local optima, and learning methods that optimize purely for reward signal often fail to learn strategies for overcoming them. Deep neuroevolution and novelty search have been proposed as effective ... More
On the Generalizability of Linear and Non-Linear Region of Interest-Based Multivariate Regression Models for fMRI DataFeb 03 2018In contrast to conventional, univariate analysis, various types of multivariate analysis have been applied to functional magnetic resonance imaging (fMRI) data. In this paper, we compare two contemporary approaches for multivariate regression on task-based ... More
What is a Theorem?Mar 30 2017General acceptance of a mathematical proposition $P$ as a theorem requires convincing evidence that a proof of $P$ exists. But what constitutes "convincing evidence?" I will argue that, given the types of evidence that are currently accepted as convincing, ... More
SUSY QCD Corrections to Associated Higgs-bottom Quark ProductionSep 28 2007Nov 13 2007The associated production of a Higgs boson with a b quark is a discovery mode for an MSSM Higgs boson at large tan beta. We compute the SUSY QCD corrections from gluino and squark loops to this process and combine them with the order alpha_s^2 NLO QCD ... More
Higgs boson production with one bottom quark including higher-order soft-gluon correctionsMay 01 2007Jul 12 2007A Higgs boson produced in association with one or more bottom quarks is of great theoretical and experimental interest to the high-energy community. A precise prediction of its total and differential cross-section can have a great impact on the discovery ... More
Rational curves of degree 11 on a general quintic threefoldNov 17 2007Apr 02 2010We prove that the incidence scheme of rational curves of degree 11 on quintic threefolds is irreducible. This implies a strong form of the Clemens conjecture in degree 11. Namely, on a general quintic threefold $F$ in $\mathbb{P}^4$, there are only finitely ... More
Rademacher Series for $η$-QuotientsOct 10 2017Oct 26 2017We apply Rademacher's method in order to compute the Fourier coefficients of a large class of $\eta$-quotients.
Rational curves of degree 16 on a general heptic fourfoldJun 13 2012According to a conjecture of H. Clemens, the dimension of the space of rational curves on a general projective hypersurface should equal the number predicted by a na\"ive dimension count. In the case of a general hypersurface of degree 7 in $\mathbb{P}^5$, ... More
The Integral Cohomology of the Bianchi GroupsSep 27 2002We calculate the integral cohomology ring structure for various members of the Bianchi group family. The main tools we use are the Bockstein spectral sequence and a long exact sequence derived from Bass-Serre theory.
Counting maps from curves to projective space via graph theoryMar 18 2013In this (mostly) survey article, we give a synopsis of a number of results relating to Brill--Noether theory on curves and metric graphs, together with some speculations about the behavior of one-dimensional linear series on a class of metric graphs that ... More
Dissipative Chaos in Semiconductor SuperlatticesApr 29 1996We consider the motion of ballistic electrons in a miniband of a semiconductor superlattice (SSL) under the influence of an external, time-periodic electric field. We use the semi-classical balance-equation approach which incorporates elastic and inelastic ... More
A Module System for Domain-Specific LanguagesMay 16 2014Domain-specific languages (DSLs) are routinely created to simplify difficult or specialized programming tasks. They expose useful abstractions and design patterns in the form of language constructs, provide static semantics to eagerly detect misuse of ... More
Automated U.S Diplomatic Cables Security Classification: Topic Model Pruning vs. Classification Based on ClustersMar 07 2017The U.S Government has been the target for cyber-attacks from all over the world. Just recently, former President Obama accused the Russian government of the leaking emails to Wikileaks and declared that the U.S. might be forced to respond. While Russia ... More
Oort cloud asteroids: Collisional evolution, the Nice Model, and the Grand TackMar 07 2019If the Solar system had a history of planet migration, the signature of that migration may be imprinted on the populations of asteroids and comets that were scattered in the planets' wake. Here, we consider the dynamical and collisional evolution of inner ... More
Power-Law Wrinkling Turbulence-Flame Interaction Model for Astrophysical FlamesFeb 18 2014We extend a model for turbulence-flame interactions (TFI) to consider astrophysical flames with a particular focus on combustion in type Ia supernovae. The inertial range of the turbulent cascade is nearly always under-resolved in simulations of astrophysical ... More
Higgs boson production with one bottom quark jet at hadron collidersAug 05 2004We present total rates and kinematic distributions for the associated production of a single bottom quark and a Higgs boson at the Tevatron and the LHC. We include next-to-leading order QCD corrections and compare the results obtained in the four and ... More
Dark Matter on TopApr 07 2014May 16 2014We consider a simplified model of fermionic dark matter which couples exclusively to the right-handed top quark via a renormalizable interaction with a color-charged scalar. We first compute the relic abundance of this type of dark matter and investigate ... More
Characteristics and Estimates of Double Parton Scattering at the Large Hadron ColliderNov 27 2009We evaluate the kinematic distributions in phase space of 4-parton final-state subprocesses produced by double parton scattering, and we contrast these with the final-state distributions that originate from conventional single parton scattering. Our goal ... More
Higgs Triplets, Decoupling, and Precision MeasurementsSep 24 2008Electroweak precision data has been extensively used to constrain models containing physics beyond that of the Standard Model. When the model contains Higgs scalars in representations other than SU(2) singlets or doublets, and hence rho not equal to one ... More
$\bar{K} + N \to K + Ξ$ reaction and $S=-1$ hyperon resonancesMar 03 2015May 25 2015The $\bar{K} + N \to K + \Xi$ reaction is studied for center-of-momentum energies ranging from threshold to 3 GeV in an effective Lagrangian approach that includes the hyperon $s$- and $u$-channel contributions as well as a phenomenological contact amplitude. ... More
Chain Recurrence For General SpacesJul 30 2017The chain relation, due to Conley, and the strong chain relation, due to Easton, are well studied for continuous maps on compact metric spaces. Following Fathi and Pageault, we use barrier functions to generalize the theory to general relations on uniform ... More
Nonlinearity in Oscillatory Flow over Sand RippleSep 12 2009In this report, We investigated the nonlinear phenomena in the study of flow dynamics of velocity component. In our studies, we observed nonlinear term in the vertical component of velocity by vittori et al \cite{vit} The time series simulation of vertical ... More
Inertial-Range Reconnection in Magnetohydrodynamic Turbulence and in the Solar WindMar 02 2015In situ spacecraft data on the solar wind show events identified as magnetic reconnection with outflows and apparent "`$X$-lines" $10^{3-4}$ times ion scales. To understand the role of turbulence at these scales, we make a case study of an inertial-range ... More
Number-resolved imaging of $^{88}$Sr atoms in a long working distance optical tweezerApr 05 2019Apr 18 2019We demonstrate the number-resolved detection of individual strontium atoms in an optical tweezer. Using a long-working distance low numerical aperture (NA = 0.26) tweezer, we avoid parity projection due to light-assisted collisions, and are able to resolve ... More
On Uniform Large-Scale Volume Growth for the Carnot-Carathéodory Metric on Unbounded Model Hypersurfaces in $\mathbb{C}^2$Aug 05 2016Mar 09 2017We consider the rate of volume growth of large Carnot-Carath\'eodory metric balls on a class of unbounded model hypersurfaces in $\mathbb{C}^2$. When the hypersurface has a uniform global structure, we show that a metric ball of radius $\delta \gg 1$ ... More
Average Frobenius distribution for the degree two primes of a number fieldSep 19 2011Jul 05 2013Let $K$ be a number field and $r$ an integer. Given an elliptic curve $E$, defined over $K$, we consider the problem of counting the number of degree two prime ideals of $K$ with trace of Frobenius equal to $r$. Under certain restrictions on $K$, we show ... More
Shrinking the Quadratic EstimatorOct 08 2011We study a regression characterization for the quadratic estimator of weak lensing, developed by Hu and Okamoto (2001,2002), for cosmic microwave background observations. This characterization motivates a modification of the quadratic estimator by an ... More
Liouville Brownian Motion and Thick Points of the Gaussian Free FieldDec 04 2014We find a lower bound for the Hausdorff dimension that a Liouville Brownian motion spends in $\alpha$-thick points of the Gaussian Free Field, where $\alpha$ is not necessarily equal to the parameter used in the construction of the geometry. This completes ... More
Flexible constraint satisfiability and a problem in semigroup theoryDec 10 2015We examine some flexible notions of constraint satisfaction, observing some relationships between model theoretic notions of universal Horn class membership and robust satisfiability. We show the \texttt{NP}-completeness of $2$-robust monotone 1-in-3 ... More
Natural dualities, nilpotence and projective planesJun 13 2014We use an interpretation of projective planes to show the inherent nondualisability of some finite semigroups. The method is sufficiently flexible to demonstrate the nondualisability of (asymptotically) almost all finite semigroups as well as to give ... More
The Hubble ConstantSep 25 2007Nov 20 2014I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual ... More
Higgs in Space!Nov 30 2009Mar 18 2010We consider the possibility that the Higgs can be produced in dark matter annihilations, appearing as a line in the spectrum of gamma rays at an energy determined by the masses of the WIMP and the Higgs itself. We argue that this phenomenon occurs generally ... More
The Higgs Mechanism and Loop-induced Decays of a Scalar into Two Z BosonsNov 17 2009Feb 05 2010We discuss general on-shell couplings of a scalar with two Z bosons using an operator analysis. In addition to the operator originated from the Higgs mechanism, two dimension-five operators, one CP-even and one CP-odd, are generated only at the loop-level. ... More
Spectroscopy of the near-nuclear regions of Cygnus A: estimating the mass of the supermassive black holeFeb 25 2003We use a combination of high spatial resolution optical and near-IR spectroscopic data to make a detailed study of the kinematics of the NLR gas in the near-nuclear regions of the powerful, FRII radio galaxy Cygnus A (z=0.0560), with the overall goal ... More
A Survey for Very Short-Period Planets in the Kepler DataAug 06 2013Nov 20 2013We conducted a search for very short-period transiting objects in the publicly available Kepler dataset. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than twelve hours. We have analyzed the data for these ... More
The Redshift Cutoff and the Quasar EpochJan 22 1998We have obtained complete redshift information for a sample of 442 radio-loud quasars with flux densities S(11cm) >= 0.25Jy. These come from a completely-identified sample of 878 flat-spectrum radio sources, so there is no optical magnitude limit. With ... More
The Parkes quarter-Jansky flat-spectrum sample 3. Space density and evolution of QSOsAug 06 2004Jan 17 2005We analyze the Parkes quarter-Jansky flat-spectrum sample of QSOs in terms of space density, including the redshift distribution, the radio luminosity function, and the evidence for a redshift cutoff. With regard to the luminosity function, we note the ... More
Laser frequency stabilization using a transfer interferometerFeb 22 2018We present a laser frequency stabilization system that uses a transfer interferometer to stabilize slave lasers to a reference laser. Our implementation uses off-the-shelf optical components along with microcontroller-based digital feedback, and offers ... More
Gamma-ray lines and One-Loop Continuum from s-channel Dark Matter AnnihilationsFeb 07 2013Nov 04 2013The era of indirect detection searches for dark matter has begun, with the sensitivities of gamma-ray detectors now approaching the parameter space relevant for weakly interacting massive particles. In particular, gamma ray lines would be smoking gun ... More
New physics in resonant production of Higgs boson pairsJul 31 2014We advocate a search for an extended scalar sector at the LHC via $hh$ production, where $h$ is the 125 GeV Higgs boson. A resonance feature in the $hh$ invariant mass is a smoking gun of an $s$-channel heavy Higgs resonance, $H$. With one $h$ decaying ... More
$K$-weight bounds for $γ$-hyperelliptic semigroupsDec 01 2018In this note, we show that {\it $\gamma$-hyperelliptic} numerical semigroups of genus $g \gg \gamma$ satisfy a refinement of a well-known characteristic weight inequality due to Torres. The refinement arises from substituting the usual notion of weight ... More
Lattice Diagrams of Knots and Diagrams of Lattice Stick KnotsMar 09 2018We give a simple example showing that a knot or link diagram that lies in the ${\mathbb{Z}}^2$ lattice is not necessarily the projection of a lattice stick knot or link in the ${\mathbb{Z}}^3$ lattice, and we give a necessary and sufficient condition ... More
Signatures of broken parity and time-reversal symmetry in generalized string-net modelsMay 23 2016Sep 21 2016We study indicators of broken time-reversal and parity symmetries in gapped topological phases of matter. We focus on phases realized by Levin-Wen string-net models, and generalize the string-net model to describe phases which break parity and time-reversal ... More
The Anisotropy of MHD Alfvénic TurbulenceMar 27 2000Jun 14 2000We perform direct 3-dimensional numerical simulations for magnetohydrodynamic (MHD) turbulence in a periodic box of size $2\pi$ threaded by strong uniform magnetic fields. We use a pseudo-spectral code with hyperviscosity and hyperdiffusivity to solve ... More
Real inflection points of real linear series on an elliptic curveApr 18 2018Given a real elliptic curve $E$ with non-empty real part and $[D]\in \mbox{Pic}^2 E$ its $g_2^1$, we study the real inflection points of distinguished subseries of the complete real linear series $|\mathcal{L}_\mathbb{R}(kD)|$ for $k\geq 3$. We define ... More
Finite field elements of high order arising from modular curvesOct 12 2012In this paper, we recursively construct explicit elements of provably high order in finite fields. We do this using the recursive formulas developed by Elkies to describe explicit modular towers. In particular, we give two explicit constructions based ... More
EBIT Observation of Ar Dielectronic Recombination Lines Near the Unknown Faint X-Ray Feature Found in the Stacked Spectrum of Galaxy ClustersFeb 04 2019Motivated by possible atomic origins of the unidentified emission line detected at 3.55 keV to 3.57 keV in a stacked spectrum of galaxy clusters (Bulbul et al. 2014), an electron beam ion trap (EBIT) was used to investigate the resonant dielectronic recombination ... More
Reply to Comment on "Reevaluation of the parton distribution of strange quarks in the nucleon"Aug 17 2015Dec 02 2015A Comment on the recently published reevaluation of the polarization-averaged parton distribution of strange quarks in the nucleon using final data on the multiplicities of charged kaons in semi-inclusive deep-inelastic scattering is reviewed. Important ... More
Rotating Bose-Einstein condensates: Closing the gap between exact and mean-field solutionsJan 22 2015When a Bose-Einstein condensed cloud of atoms is given some angular momentum, it forms vortices arranged in structures with a discrete rotational symmetry. For these vortex states, the Hilbert space of the exact solution separates into a "primary" space ... More
Warm Molecular Gas Traced with CO J=7->6 in the Galaxy's Central 2 Parsecs: Dynamical Heating of the Circumnuclear DiskJan 03 2005We present an 11 arcsec resolution map of the central two parsecs of the Galaxy in the CO J =7->6 rotational transition. The CO emission shows rotation about Sgr A*, but also evidence for non-circular turbulent motion and a clumpy morphology. We combine ... More
Bayesian determination of the effect of a deep eutectic solvent on the structure of lipid monolayersOct 17 2018Feb 28 2019In this work, we present the first example of the self-assembly of phospholipid monolayers at the interface between air and an ionic solvent. Deep eutectic solvents are a novel class of environmentally friendly non-aqueous room temperature liquids with ... More
Cosmic Chandlery with Thermonuclear SupernovaeDec 06 2016Thermonuclear (Type Ia) supernovae are bright stellar explosions, the light curves of which can be calibrated to allow for use as "standard candles" for measuring cosmological distances. Contemporary research investigates how the brightness of an event ... More
A method for efficient measurement of gravitational lens time delaysNov 30 2010The Hubble constant value is currently known to 10% accuracy unless assumptions are made for the cosmology (Sandage et al. 2006). Gravitational lens systems provide another probe of the Hubble constant using time delay measurements. However, current investigations ... More
Extracting scaling laws from numerical dynamo modelsJul 15 2013Earth's magnetic field is generated by processes in the electrically conducting, liquid outer core, subsumed under the term `geodynamo'. In the last decades, great effort has been put into the numerical simulation of core dynamics following from the magnetohydrodynamic ... More
MDMP: Managed Data Message PassingApr 29 2013MDMP is a new parallel programming approach that aims to provide users with an easy way to add parallelism to programs, optimise the message passing costs of traditional scientific simulation algorithms, and enable existing MPI-based parallel programs ... More
Nonperturbative investigations of SU(3) gauge theory with eight dynamical flavorsJul 23 2018Jan 16 2019We present our lattice studies of SU(3) gauge theory with $N_f$ = 8 degenerate fermions in the fundamental representation. Using nHYP-smeared staggered fermions we study finite-temperature transitions on lattice volumes as large as $L^3 \times N_t = 48^3 ... More
Nonperturbative Renormalization of Operators in Near-Conformal Systems Using Gradient FlowsJun 04 2018Nov 16 2018We propose a continuous real space renormalization group transformation based on gradient flow, allowing for a numerical study of renormalization without the need for costly ensemble matching. We apply our technique in a pilot study of SU$(3)$ gauge theory ... More
A holographic perspective on non-relativistic conformal defectsMar 11 2009We study defects in non-relativistic conformal field theories. As in the well-studied case of relativistic conformal defects, we find that a useful tool to organize correlation functions is the defect operator expansion (dOPE). We analyze how the dOPE ... More
Magnetized baryonic matter in holographic QCDJun 02 2008We investigate the properties of the Sakai-Sugimoto model at finite magnetic field and baryon chemical potentials. We show that in a finite magnetic field, there exists a spatially homogeneous configuration carrying finite baryon number density. At low ... More
Domain Adaptation for Real-Time Student Performance PredictionSep 07 2018Mar 17 2019Increasingly fast development and update cycle of online course contents, and diverse demographics of students in each online classroom, make student performance prediction in real-time (before the course finishes) and/or on curriculum without specific ... More
The Use of Unlabeled Data versus Labeled Data for Stopping Active Learning for Text ClassificationJan 26 2019Annotation of training data is the major bottleneck in the creation of text classification systems. Active learning is a commonly used technique to reduce the amount of training data one needs to label. A crucial aspect of active learning is determining ... More
Fermion condensation and super pivotal categoriesSep 06 2017May 19 2018We study fermionic topological phases using the technique of fermion condensation. We give a prescription for performing fermion condensation in bosonic topological phases which contain a fermion. Our approach to fermion condensation can roughly be understood ... More
MHD Turbulence: Scaling Laws and Astrophysical ImplicationsMay 17 2002Turbulence is the most common state of astrophysical flows. In typical astrophysical fluids, turbulence is accompanied by strong magnetic fields, which has a large impact on the dynamics of the turbulent cascade. Recently, there has been a significant ... More
Learning Discrete Weights Using the Local Reparameterization TrickOct 21 2017Feb 02 2018Recent breakthroughs in computer vision make use of large deep neural networks, utilizing the substantial speedup offered by GPUs. For applications running on limited hardware, however, high precision real-time processing can still be a challenge. One ... More
Computing automorphism groups of shifts using atypical equivalence classesMay 11 2015Feb 01 2017We study the automorphism group of an infinite minimal shift $(X,\sigma)$ such that the complexity difference function, $p(n+1)-p(n)$, is bounded. We give some new bounds on $\mbox{Aut}(X,\sigma)/\langle \sigma \rangle$ and also study the one-sided case. ... More
A short proof of a theorem of Cobham on substitutionsAug 23 2011This paper is concerned with the lengths of constant length substitutions that generate topologically conjugate systems. We show that if the systems are infinite, then these lengths must be powers of the same integer. This result is a dynamical formulation ... More
A Characterization of the Morse Minimal Set up to Topological ConjugacyJun 19 2007Jan 30 2013We establish necessary and sufficient conditions for a dynamical system to be topologically conjugate to the Morse minimal set, the shift orbit closure of the Morse sequence, and conditions for topological conjugacy to the closely related Teoplitz minimal ... More
Joint Design of Convolutional Code and CRC under Serial List Viterbi DecodingNov 29 2018This paper studies the joint design of optimal convolutional codes (CCs) and CRC codes when serial list Viterbi algorithm (S-LVA) is employed in order to achieve the target frame error rate (FER). We first analyze the S-LVA performance with respect to ... More
Transversity and Spin Structure FunctionsAug 24 2004Measurements of single-spin asymmetries for semi-inclusive electro-production of pions and kaons in deep-inelastic scattering with transverse target polarization open a new window on the transverse quark and gluon structure of the nucleon. The first experimental ... More
Low-shear QCD plasma from perturbation theoryApr 20 2017We argue that the phenomenologically inferred ratio of shear viscosity to entropy density of the quark-gluon plasma, $\eta/\s < 0.5$ near the deconfinement temperature $T_c$, can be understood from perturbative QCD. To rebut the widespread, opposite view ... More
Monoids with tests and the algebra of possibly non-halting programsAug 19 2014We study the algebraic theory of computable functions, which can be viewed as arising from possibly non-halting computer programs or algorithms, acting on some state space, equipped with operations of composition, {\em if-then-else} and {\em while-do} ... More
Axiomatisability and hardness for universal Horn classes of hypergraphsApr 07 2017We characterise finite axiomatisability and intractability of deciding membership for universal Horn classes generated by finite loop-free hypergraphs.
The Destruction of the Axiom of Determinacy by Forcings on $\mathbb{R}$ when $Θ$ is RegularMar 16 2019$\mathsf{ZF + AD}$ proves that for all nontrivial forcings $\mathbb{P}$ on a wellorderable set of cardinality less than $\Theta$, $1_{\mathbb{P}} \Vdash_{\mathbb{P}} \neg\mathsf{AD}$. $\mathsf{ZF + AD} + \Theta$ is regular proves that for all nontrivial ... More
Isotropic covariance functions on graphs and their edgesOct 03 2017We develop parametric classes of covariance functions on linear networks and their extension to graphs with Euclidean edges, i.e., graphs with edges viewed as line segments or more general sets with a coordinate system allowing us to consider points on ... More
Short-distance and short-time structure of a unitary Fermi gasFeb 04 2010Mar 28 2010We consider the operator product expansions for unitarity fermions. We compute the dynamic structure factor S(q,w) at large frequency and wavenumber away from the one-particle peak. The overall normalization of S(q,w) is determined by Tan's contact parameter, ... More
Constructing symplectomorphisms between symplectic torus quotientsMar 22 2019We identify a family of torus representations such that the corresponding singular symplectic quotients at the $0$-level of the moment map are graded regularly symplectomorphic to symplectic quotients associated to representations of the circle. For a ... More
The strong symmetric genus of the finite Coxeter groupsNov 20 2004The strong symmetric genus of a finite group G is the smallest genus of a closed orientable topological surface on which G acts faithfully as a group of orientation preserving automorphisms. In this paper we complete the calculation of the strong symmetric ... More
The Third Offset and a Fifth Domain? Balancing Game-Changing Innovation and Cyber Risk MitigationOct 25 2016Cyber has changed the scope of the national security mission and is placing new strains on our diplomatic, warfighting, legal, and economic/budgetary processes. Cybersecurity processes and techniques are increasingly critical to our warfighting missions, ... More
Scaling of the Detonation Product State with Reactant Kinetic EnergyJul 28 2017This submissions has been withdrawn by arXiv administrators because the submitter did not have the right to agree to our license.
Partnerships For Physics Teaching Reform -- a crucial role for universities and collegesFeb 21 1997To meet National Standards recommended by the National Research Council for high school physics, inservice teachers must be integrated into the physics community. They must be empowered by access to resources of the physics community and by sustained ... More
Approaching Conformality with Ten FlavorsApr 26 2012Jun 05 2012We present first results for lattice simulations, on a single volume, of the low-lying spectrum of an SU(3) Yang-Mills gauge theory with ten light fermions in the fundamental representation. Fits to the fermion mass dependence of various observables are ... More
Hermes and the spin of the protonAug 12 2002HERMES is a second generation experiment to study the spin structure of the nucleon, in which measurements of the spin dependent properties of semi-inclusive deep-inelastic lepton scattering are emphasized. Data have been accumulated for semi-inclusive ... More
How to implement the generalized-coherent-state POVM via nonadaptive continuous isotropic measurementMar 05 2019In a recent Letter~[PRL \textbf{121}, 130404 (2018)], it was announced that the spin-coherent-state POVM can be implemented via a nonadaptive continuous isotropic measurement. In this article, the mathematical concepts used to prove this are explained ... More
An Analysis of Stochastic Jovian Oscillation Excitation by Moist ConvectionFeb 15 2018Recent observations of Jupiter have suggested the existence of global oscillatory modes at millihertz frequencies, yet the source mechanism responsible for driving these modes is still unknown. However, the energies necessary to produce observable surface ... More
Approximate Likelihood Approaches for Detecting the Influence of Primordial Gravitational Waves in Cosmic Microwave Background PolarizationAug 31 2017One of the major targets for next-generation cosmic microwave background (CMB) experiments is the detection of the primordial B-mode signal. Planning is under way for Stage-IV experiments that are projected to have instrumental noise small enough to make ... More
Estimating deformations of isotropic Gaussian random fields on the planeApr 04 2008This paper presents a new approach to the estimation of the deformation of an isotropic Gaussian random field on $\mathbb{R}^2$ based on dense observations of a single realization of the deformed random field. Under this framework we investigate the identification ... More
How is a graph like a manifold?Jun 10 2002In this article, we discuss some classical problems in combinatorics which can be solved by exploiting analogues between graph theory and the theory of manifolds. One well-known example is the McMullen conjecture, which was settled twenty years ago by ... More
Sums of Euler products and statistics of elliptic curvesOct 20 2015Sep 26 2016We present several results related to statistics for elliptic curves over a finite field $\mathbb{F}_p$ as corollaries of a general theorem about averages of Euler products that we demonstrate. In this general framework, we can reprove known results such ... More
Co-evolving Tracing and Fault Injection with Box of PainMar 28 2019Distributed systems are hard to reason about largely because of uncertainty about what may go wrong in a particular execution, and about whether the system will mitigate those faults. Tools that perturb executions can help test whether a system is robust ... More
On the Bispectra of Very Massive Tracers in the Effective Field Theory of Large-Scale StructureOct 27 2017The Effective Field Theory of Large-Scale Structure (EFTofLSS) provides a consistent perturbative framework for describing the statistical distribution of cosmological large-scale structure. In a previous EFTofLSS calculation that involved the one-loop ... More
Monopole Taxonomy in Three-Dimensional Conformal Field TheoriesSep 04 2013We study monopole operators at the infrared fixed points of Abelian and non-Abelian gauge theories with N_f fermion flavors in three dimensions. At large N_f, independent monopole operators can be defined via the state-operator correspondence only for ... More
A proof of some conjectures of Mao on partition rank inequalitiesSep 20 2015Based on work of Atkin and Swinnerton-Dyer on partition rank difference functions, and more recent work of Lovejoy and Osburn, Mao has proved several inequalities between partition ranks modulo $10$, and additional results modulo $6$ and $10$ for the ... More
A note on the minimum skew rank of powers of pathsJul 13 2011The real minimum skew rank of a simple graph G is the smallest possible rank among all real skew symmetric matrices, whose (i,j)-entry (for i not equal to j) is nonzero whenever {i, j} is an edge in G and is zero otherwise. In this paper we study the ... More
Tiling the integers with translates of one finite setFeb 27 1998A set is said to tile the integers if and only if the integers can be written as a disjoint union of translates of that set. We consider the problem of finding necessary and sufficient conditions for a finite set to tile the integers. For sets of prime ... More
Discrete Wasserstein Barycenters: Optimal Transport for Discrete DataJul 26 2015Aug 10 2015Wasserstein barycenters correspond to optimal solutions of transportation problems for several marginals, and as such have a wide range of applications ranging from economics to statistics and computer science. When the marginal probability measures are ... More
Combined Diffusion-Relaxometry MRI to Identify Dysfunction in the Human PlacentaOct 09 2018Mar 21 2019Purpose: A combined diffusion-relaxometry MR acquisition and analysis pipeline for in-vivo human placenta, which allows for exploration of coupling between T2* and apparent diffusion coefficient (ADC) measurements in a sub 10 minute scan time. Methods: ... More
The formation and evolution of low-surface-brightness galaxiesFeb 12 2019Our statistical understanding of galaxy evolution is fundamentally driven by objects that lie above the surface-brightness limits of current wide-area surveys (mu ~ 23 mag arcsec^-2). While both theory and small, deep surveys have hinted at a rich population ... More
Gas and dust around A-type stars at tens of Myr:signatures of cometary breakupJul 13 2016Jul 18 2016Discs of dusty debris around main-sequence star indicate fragmentation of orbiting planetesimals, and for a few A-type stars, a gas component is also seen that may come from collisionally-released volatiles. Here we find the sixth example of a CO-hosting ... More
Highly polarized structures in the near-nuclear regions of Cygnus A: intrinsic anisotropy within the cones?Feb 08 2000We present near-IR imaging polarimetry observations of the nucleus of Cygnus A, taken with the NICMOS camera of the HST at a wavelength of 2.0 microns.These maps reveal a highly collimated region of polarized emission straddling the nucleus and extending ... More
CO (J=7->6) Observations of NGC 253: Cosmic Ray Heated Warm Molecular GasDec 11 2002Jan 13 2003We report observations of the CO J=7->6 transition toward the starburst nucleus of NGC 253. This is the highest-excitation CO measurement in this source to date, and allows an estimate of the molecular gas excitation conditions. Comparison of the CO line ... More