Results for "Brian J. LeRoy"

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Graphene on Hexagonal Boron NitrideJan 21 2014May 06 2014The field of graphene research has developed rapidly since its first isolation by mechanical exfoliation in 2004. Due to the relativistic Dirac nature of its charge carriers, graphene is both a promising material for next-generation electronic devices ... More
Scanning gate microscopy of ultra clean carbon nanotube quantum dotsAug 22 2015We perform scanning gate microscopy on individual suspended carbon nanotube quantum dots. The size and position of the quantum dots can be visually identified from the concentric high conductance rings. For the ultra clean devices used in this study, ... More
Evolution of the electronic band structure of twisted bilayer graphene upon dopingApr 30 2015Aug 08 2017The electronic band structure of twisted bilayer graphene develops van Hove singularities whose energy depends on the twist angle between the two layers. Using Raman spectroscopy, we monitor the evolution of the electronic band structure upon doping using ... More
Response of graphene to femtosecond high-intensity laser irradiationMay 05 2011We study the response of graphene to high-intensity 10^11-10^12 Wcm^-2, 50-femtosecond laser pulse excitation. We establish that graphene has a fairly high (~3\times10^12Wcm^-2) single-shot damage threshold. Above this threshold, a single laser pulse ... More
Pressure-induced commensurate stacking of graphene on boron nitrideMar 10 2016Combining atomically-thin van der Waals (vdW) materials into heterostructures provides a powerful path towards the creation of designer electronic devices. Interactions between the individual atomic layers of the heterostructure strongly affect the properties ... More
Pressure-induced commensurate stacking of graphene on boron nitrideMar 10 2016Jan 25 2017Combining atomically-thin van der Waals materials into heterostructures provides a powerful path towards the creation of designer electronic devices. The interaction strength between neighboring layers, most easily controlled through their interlayer ... More
Optical thickness determination of hexagonal Boron Nitride flakesMar 13 2013Mar 20 2013Optical reflectivity contrast provides a simple, fast and noninvasive method for characterization of few monolayer samples of two-dimensional materials. Here we apply this technique to measure the thickness of thin flakes of hexagonal Boron Nitride (hBN), ... More
Optical characterization of electron-phonon interactions at the saddle point in grapheneOct 10 2013The role of electron-phonon interactions is experimentally and theoretically investigated near the saddle point absorption peak of graphene. The differential optical transmission spectra of multiple, non-interacting layers of graphene reveals the dominant ... More
Ore extensions satisfying a polynomial identityJul 02 2007Necessary and sufficient conditions for an Ore extension $S=R[x;\si,\de]$ to be a {\rm PI} ring are given in the case $\si$ is an injective endomorphism of a semiprime ring $R$ satisfying the {\rm ACC} on annihilators. Also, for an arbitrary endomorphism ... More
Noncommutative symmetric functions and W-polynomialsJun 24 2006Let K,S,D be a division ring, an endomorphism and a S-derivation of K, respectively. In this setting we introduce generalized noncommutative symmetric functions and obtain Vieta formula and decompositions of differential operators. W-polynomials show ... More
Goldie conditions for Ore extensions over semiprime ringsNov 27 2004Let $R$ be a ring, $\sigma$ an injective endomorphism of $R$ and $\delta$ a $\sigma$-derivation of $R$. We prove that if $R$ is semiprime left Goldie then the same holds for the Ore extension $R[x;\sigma,\delta]$ and both rings have the same left uniform ... More
Intrinsic disorder in graphene on transition metal dichalcogenide heterostructuresNov 24 2014The electronic properties of two-dimensional materials such as graphene are extremely sensitive to their environment, especially the underlying substrate. Planar van der Waals bonded substrates such as hexagonal boron nitride (hBN) have been shown to ... More
Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron NitrideFeb 13 2012The Schr\"odinger equation dictates that the propagation of nearly free electrons through a weak periodic potential results in the opening of band gaps near points of the reciprocal lattice known as Brillouin zone boundaries. However, in the case of massless ... More
Biclosed bicategories: localisation of convolutionMay 23 2007We give a summary (without proofs) of the main results in the author's thesis entitled ``Construction of biclosed categories'' (University of New South Wales, Australia, 1970). This summary is reprinted directly from Report 81-0030 of the School of Mathematics ... More
On The Existence Of Category BicompletionsSep 28 2009A completeness conjecture is advanced concerning the free small-colimit completion P(A) of a (possibly large) category A. The conjecture is based on the existence of a small generating-cogenerating set of objects in A. We sketch how the validity of the ... More
Einstein's Physical Strategy, Energy Conservation, Symmetries, and Stability: "but Grossmann & I believed that the conservation laws were not satisfied"Mar 24 2016Recent work on the history of General Relativity by Renn, Sauer, Janssen et al. shows that Einstein found his field equations partly by a physical strategy including the Newtonian limit, the electromagnetic analogy, and energy conservation. Such themes ... More
Gauge-Invariant Localization of Infinitely Many Gravitational Energies from All Possible Auxiliary StructuresFeb 08 2009Jul 22 2009The problem of finding a covariant expression for the distribution and conservation of gravitational energy-momentum dates to the 1910s. A suitably covariant infinite-component localization is displayed, reflecting Bergmann's realization that there are ... More
Absolute Objects and Counterexamples: Jones-Geroch Dust, Torretti Constant Curvature, Tetrad-Spinor, and Scalar DensityJun 20 2005Feb 28 2006James L. Anderson analyzed the novelty of Einstein's theory of gravity as its lack of "absolute objects." Michael Friedman's related work has been criticized by Roger Jones and Robert Geroch for implausibly admitting as absolute the timelike 4-velocity ... More
Constrained Dynamics of Universally Coupled Massive Spin 2-spin 0 GravitiesJan 25 2006The 2-parameter family of massive variants of Einstein's gravity (on a Minkowski background) found by Ogievetsky and Polubarinov by excluding lower spins can also be derived using universal coupling. A Dirac-Bergmann constrained dynamics analysis seems ... More
Supernova Remnants as a Probe of Dust Grains in the Interstellar MediumMay 07 2010Interstellar dust grains play a crucial role in the evolution of the galactic interstellar medium (ISM). Despite its importance, however, dust remains poorly understood in terms of its origin, composition, and abundance throughout the universe. Supernova ... More
Note On Analytic Functors As Fourier TransformsJun 18 2009Apr 25 2010Several notions of "analytic" functor introduced recently in the literature fit into the graphic fourier transform context presented in [D].
Monoidal functor categories and graphic Fourier transformsDec 18 2006This article represents a preliminary attempt to link Kan extensions, and some of their further developments, to Fourier theory and quantum algebra through *-autonomous monoidal categories and related structures.
Beyond the Standard Model: LHC Phenomenology, Cosmology from Post-Inflationary Sources, and Dark Matter PhysicsAug 24 2013It is the goal of this dissertation to demonstrate that beyond the standard model, certain theories exist which solve conflicts between observation and theory -- conflicts such as massive neutrinos, dark matter, unstable Higgs vacuum, and recent Planck ... More
Compact convolutionMay 17 2006We state a Yoneda-type lemma which leads to various functor categories being compact closed.
The mean-square of Dirichlet L-functionsAug 20 2007We verify the conjecture of [CFKRS] for the mean square near the critical point of Dirichlet L-functions for a composite modulus q. We also prove a kind of reciprocity formula when the second moment for a prime modulus is twisted by a character evaluated ... More
Vicinal silicon surfaces: from step density wave to facetingJun 15 2007This paper investigates faceting mechanisms induced by electromigration in the regime where atomic steps are transparent. For this purpose we study several vicinal orientations by means of in-situ (optical diffraction, electronic microscopy) as well as ... More
Integration of a gate electrode into carbon nanotube devices for scanning tunneling microscopyFeb 21 2005We have developed a fabrication process for incorporating a gate electrode into suspended single-walled carbon nanotube structures for scanning tunneling spectroscopy studies. The nanotubes are synthesized by chemical vapor deposition directly on a metal ... More
Scanning Tunneling Spectroscopy of Suspended Single-Wall Carbon NanotubesMar 12 2004We have performed low-temperature STM measurements on single-wall carbon nanotubes that are freely suspended over a trench. The nanotubes were grown by CVD on a Pt substrate with predefined trenches etched into it. Atomic resolution was obtained on the ... More
Electrical generation and absorption of phonons in carbon nanotubesJan 21 2005The interplay between discrete vibrational and electronic degrees of freedom directly influences the chemical and physical properties of molecular systems. This coupling is typically studied through optical methods such as fluorescence, absorption, and ... More
Exploration of Self-Propelling Droplets Using a Curiosity Driven Robotic AssistantApr 22 2019We describe a chemical robotic assistant equipped with a curiosity algorithm (CA) that can efficiently explore the state a complex chemical system can exhibit. The CA-robot is designed to explore formulations in an open-ended way with no explicit optimization ... More
On the Selberg class of Dirichlet series: small weightsApr 01 1992In the study of Dirichlet series with arithmetic significance there has appeared (through the study of known examples) certain expectations, namely (i) if a functional equation and Euler product exists, then it is likely that a type of Riemann hypothesis ... More
Infrared Emission from Supernova Remnants: Formation and Destruction of DustNov 03 2017We review the observations of dust emission in supernova rem- nants (SNRs) and supernovae (SNe). Theoretical calculations suggest that SNe, particularly core-collapse, should make significant quantities of dust, perhaps as much as a solar mass. Observations ... More
Energy Absorption and Low Velocity Impact Response of Open-Cell Polyurea FoamsOct 08 2018The energy absorption and impact attenuation of low density polyurea (PU) foams (140 - 220 kg/m3) is presented. The stress-strain behavior, energy absorption, cushioning efficiency, and energy return (resilience) are measured at a quasi-static strain ... More
The Effect of Disorder in Superfluid Double Layer GrapheneApr 12 2011We investigate the superfluid properties of disordered double layer graphene systems using the non-equilibrium Green's function (NEGF) formalism. The complexity of such a structure makes it imperative to study the effects of lattice vacancies which will ... More
Strong [O III] and [N II] emission lines in globular clusters from photoionized R Corona Borealis star windsOct 28 2010The globular cluster X-ray source CXO J033831.8-352604 in NGC 1399 has recently been found to show strong emission lines of [O III] and [N II] in its optical spectrum in addition to ultraluminous X-ray emission with a soft X-ray spectrum. It was further ... More
Spacing of zeros of Hecke L-functions and the class number problemNov 01 2001We derive strong and effective lower bounds for the class number h(q) of the imaginary quadratic field Q(\sqrt{-q}), conditionally subject to the existence of many small (subnormal) gaps between zeros of the L-function associated with a character of the ... More
A multivariate semiparametric Bayesian spatial modeling framework for hurricane surface wind fieldsSep 04 2007Storm surge, the onshore rush of sea water caused by the high winds and low pressure associated with a hurricane, can compound the effects of inland flooding caused by rainfall, leading to loss of property and loss of life for residents of coastal areas. ... More
A Supergiant Supernova-Blown Bubble in the Spiral Galaxy NGC 1620Dec 06 1994We present UBR and H$\alpha$ imaging of NGC 1620, a highly inclined spiral galaxy that contains a large scale, arc-like feature of radius 3 kpc in its outer disk at a distance of $\sim$ 11 kpc from the center. What is unusual about this arc-like feature ... More
Enhanced Hierarchical Music Structure Annotations via Feature Level Similarity FusionFeb 04 2019We describe a novel pipeline to automatically discover hierarchies of repeated sections in musical audio. The proposed method uses similarity network fusion (SNF) to combine different frame-level features into clean affinity matrices, which are then used ... More
A latent factor model for spatial data with informative missingnessOct 07 2010A large amount of data is typically collected during a periodontal exam. Analyzing these data poses several challenges. Several types of measurements are taken at many locations throughout the mouth. These spatially-referenced data are a mix of binary ... More
Discussion of "Statistical Modeling of Spatial Extremes" by A. C. Davison, S. A. Padoan and M. RibatetAug 17 2012Discussion of "Statistical Modeling of Spatial Extremes" by A. C. Davison, S. A. Padoan and M. Ribatet [arXiv:1208.3378].
A Fokker-Planck reaction model for the epitaxial growth and shape transition of quantum dotsApr 11 2017We construct a Fokker-Planck reaction model to investigate the dynamics of the coupled epitaxial growth and shape transition process of an array of quantum dots. The Fokker-Planck reaction model is based on a coupled system of Fokker-Planck equations ... More
Lognormal properties of SGR 1806-20 and the Possibility of a Quiescent Population of other SGR sourcesJul 21 1998Monte Carlo simulations of long SGR event sequences based on lognormal distributions with a range of time intervals and intensity distribution parameters have been investigated. The main conclusions are that the majority of SGRs with properties similar ... More
A spatial capture-recapture model for territorial speciesMay 08 2014Advances in field techniques have lead to an increase in spatially-referenced capture-recapture data to estimate a species' population size as well as other demographic parameters and patterns of space usage. Statistical models for these data have assumed ... More
Enriched Herds And Finite Quantum GroupoidsMay 15 2010We describe a finite quantum groupoid associated to any finite Vect_k enriched herd.
Limits of small functorsOct 13 2006For a small category K enriched over a suitable monoidal category V, the free completion of K under colimits is the presheaf category [K*,V]. If K is large, its free completion under colimits is the V-category PK of small presheaves on K, where a presheaf ... More
Local Spectroscopic Characterization of Spin and Layer Polarization in WSe$_2$May 01 2015Jul 29 2015We report scanning tunneling microscopy (STM) and spectroscopy (STS) measurements of monolayer and bilayer WSe$_2$. We measure a band gap of 2.21 $\pm$ 0.08 eV in monolayer WSe$_2$, which is much larger than the energy of the photoluminescence peak indicating ... More
Coauthorship and citation in scientific publishingApr 01 2013A large number of published studies have examined the properties of either networks of citation among scientific papers or networks of coauthorship among scientists. Here, using an extensive data set covering more than a century of physics papers published ... More
An efficient and principled method for detecting communities in networksApr 18 2011A fundamental problem in the analysis of network data is the detection of network communities, groups of densely interconnected nodes, which may be overlapping or disjoint. Here we describe a method for finding overlapping communities based on a principled ... More
No Escape from the Supernova! Magnetic Imprisonment of Dusty Pinballs by a Supernova RemnantJan 21 2018Motivated by recent measurements of deposits of $^{60}$Fe on the ocean floor and the lunar surface, we model the transport of dust grains containing $^{60}$Fe from a near-Earth (i.e., within 100 pc) supernova (SN). We inject dust grains into the environment ... More
Radioactive Iron Rain: Transporting $^{60}$Fe in Supernova Dust to the Ocean FloorApr 04 2016Jun 07 2016Several searches have found evidence of $^{60}$Fe deposition, presumably from a near-Earth supernova (SN), with concentrations that vary in different locations on Earth. This paper examines various influences on the path of interstellar dust carrying ... More
Conformal symmetry classes for pp-wave spacetimesAug 07 2013We determine conformal symmetry classes for the pp-wave spacetimes. This refines the isometry classification scheme given by Sippel and Goenner (1986 {\it Gen. Rel. Grav.} {\bf 18} 1229). It is shown that every conformal Killing vector for the null fluid ... More
Testing Landau gauge OPE on the Lattice with a $<A^2>$ CondensateJan 26 2001Jan 27 2001Using the operator product expansion we show that the $O(1/p^2)$ correction to the perturbative expressions for the gluon propagator and the strong coupling constant resulting from lattice simulations in the Landau gauge are due to a non-vanishing vacuum ... More
Asymptotic behaviour of the gluon propagator from lattice QCDMar 16 1999Feb 15 2001We study the flavorless gluon propagator in the Landau gauge from high statistics lattice calculations. Hypercubic artifacts are efficiently eliminated by taking the $\sum p_\mu^4 \to 0$ limit. The propagator is fitted to the three-loops perturbative ... More
Asymptotic scaling of the gluon propagtor on the latticeOct 01 1999We pursue the study of the high energy behaviour of the gluon propagator on the lattice in the Landau gauge in the flavorless case (n_f=0). It was shown in a precedin g paper that the gluon propagator did not reach three-loop asymptotic scaling at an ... More
Preliminaries on a Lattice Analysis of The Pion Light-cone Wave function: a Partonic Signal?May 22 2001We present the first attempt of a new method to compute the pion light-cone wave function (LCWF) on the lattice. We compute the matrix element between the pion and the vacuum of a non-local operator: the propagator of a ``scalar quark'' (named for short ... More
Théorie de la mesure dans les lieux réguliers. ou : Les intersections cachées dans le paradoxe de Banach-TarskiMar 22 2013It is well known that axiom of choice implies the existence of non-measurable sets for Lebesgue's measure on R as well as the existence of "paradoxical" decompositions of the unit ball of R^3 (Banach-Tarski). This is generally interpreted as the price ... More
On the IR behaviour of the Landau-gauge ghost propagatorMar 14 2008We examine analytically the ghost propagator Dyson-Schwinger Equation (DSE) in the deep IR regime and prove that a finite ghost dressing function at vanishing momentum is an alternative solution (solution II) to the usually assumed divergent one (solution ... More
Gluon propagator, triple gluon vertex and the QCD coupling constantAug 31 1999We study the UV-scaling of the flavorless gluon propagator in the Landau gauge in an energy window up to 9 GeV. Dominant hypercubic lattice artifacts are eliminated. A large set of renormalization schemes is used to test asymptotic scaling. We compare ... More
A Ghost Story: Ghosts and Gluons in the IR regime of QCDNov 03 2009We discuss the different methods to obtain reliable informations about the deep infra-red behaviour of the gluon and ghost Green functions in QCD. We argue that a clever combination of analytical inputs and numerical ones is necessary. We illustrate this ... More
IR finiteness of the ghost dressing function from numerical resolution of the ghost SD equationJan 17 2008Mar 17 2008We solve numerically the Schwinger-Dyson (SD hereafter) ghost equation in the Landau gauge for a given gluon propagator finite at k=0 (alpha_gluon=1) and with the usual assumption of constancy of the ghost-gluon vertex ; we show that there exist two possible ... More
The Pion Light-Cone Wave Function Phi_pi on the lattice: a partonic signal?Oct 22 2001We determine the conditions required to study the pion light-cone wave function Phi_pi with a new method: a direct display of the partons constituting the pion. We present the preliminary results of a lattice computation of Phi_pi following this direction. ... More
Noncommutative polynomial mapsAug 01 2012Polynomial maps attached to polynomials of an Ore extension are naturally defi ned. In this setting we show the importance of pseudo-linear transformations and give some applications. In particular, factorizations of polynomials in an Ore extension over ... More
mu-Squared Dependent Deviation of the Non Perturbative ZA,MOM from the True Axial Renormalisation Constant, Implied by Ward IdentityMar 31 2015Apr 02 2015It is recalled why, as already stated in a previous paper, there seems to be an inconsistency in identifying the non perturbative ZA,MOM as the renormalisation of the axial current, or equivalently, in setting as normalisation condition that the renormalised ... More
Consistent OPE Description of Gluon Two- and Three-point Green Function?Aug 04 2000Aug 07 2000We perform an OPE analysis of the flavorless non-perturbative gluon propagator and the symmetric three-gluon vertex in the Landau gauge. The first subdominant operator is $A_\mu A^\mu$ which can condensate in the Landau gauge ``vacuum'' although being ... More
An $S$-adic characterization of minimal subshifts with first difference of complexity $1 \leq p(n+1) - p(n) \leq 2$May 02 2013In [Ergodic Theory Dynam. System, 16 (1996) 663--682], S. Ferenczi proved that any minimal subshift with first difference of complexity bounded by 2 is $S$-adic with $\card S \leq 3^{27}$. In this paper, we improve this result by giving an $S$-adic charaterization ... More
On the leading OPE corrections to the ghost-gluon vertex and the Taylor theoremSep 17 2011Jan 19 2012This brief note is devoted to a study of genuine non-perturbative corrections to the Landau gauge ghost-gluon vertex in terms of the non-vanishing dimension-two gluon condensate. We pay special attention to the kinematical limit which the bare vertex ... More
Lattice calculation of $α_s$ in momentum schemeOct 12 1998Oct 26 1998We compute the flavorless running coupling constant of QCD from the three gluon vertex in the (regularisation independent) momentum subtraction renormalisation scheme. This is performed on the lattice with high statistics. The expected color dependence ... More
Magnetic characterization of the frustrated three-leg ladder compound [(CuCl2tachH)3Cl]Cl2Mar 22 2004Aug 11 2004We report the magnetic features of a new one-dimensional stack of antiferromagnetically coupled equilateral copper(II) triangles. High-field magnetization measurements show that the interaction between the copper triangles is of the same order of magnitude ... More
Two body scattering length of Yukawa model on a latticeOct 13 2006The extraction of scattering parameters from Euclidean simulations of a Yukawa model in a finite volume with periodic boundary conditions is analyzed both in non relativistic quantum mechanics and in quantum field theory.
Three-terminal scanning tunneling spectroscopy of suspended carbon nanotubesApr 15 2005We have performed low-temperature scanning tunneling spectroscopy measurements on suspended single-wall carbon nanotubes with a gate electrode allowing three-terminal spectroscopy measurements. These measurements show well-defined Coulomb diamonds as ... More
Yukawa model on a lattice: two body statesOct 13 2006We present first results of the solutions of the Yukawa model as a Quantum Field Theory (QFT) solved non perturbatively with the help of lattice calculations. In particular we will focus on the possibility of binding two nucleons in the QFT, compared ... More
Heavy to light vector meson semileptonic decaysSep 12 2002New (preliminary) results for the form factors relevant for the semileptonic decays of heavy pseudoscalar to a light vector meson are presented. In particular, we discuss the form factors for D --> K* and B --> rho modes.
High moments of the Riemann zeta-functionFeb 01 1999The authors describe a general approach which, in principal, should produce the correct (conjectural) formula for every even integer moment of the Riemann zeta function. They carry it out for the sixth and eigth powers; in the case of sixth powers this ... More
A hierarchical max-stable spatial model for extreme precipitationJan 08 2013Extreme environmental phenomena such as major precipitation events manifestly exhibit spatial dependence. Max-stable processes are a class of asymptotically-justified models that are capable of representing spatial dependence among extreme values. While ... More
A message passing approach for general epidemic modelsMar 29 2010Jul 22 2010In most models of the spread of disease over contact networks it is assumed that the probabilities per unit time of disease transmission and recovery from disease are constant, implying exponential distributions of the time intervals for transmission ... More
SOFIA Observations of SN 2010jl: Another Non-Detection of the 9.7 $μ$m Silicate Dust FeatureJun 30 2015We present photometric observations from the {\it Stratospheric Observatory for Infrared Astronomy (SOFIA)} at 11.1 $\mu$m of the Type IIn supernova (SN IIn) 2010jl. The SN is undetected by {\it SOFIA}, but the upper limits obtained, combined with new ... More
Photon wave functions, wave-packet quantization of light, and coherence theoryAug 06 2007Dec 09 2007The monochromatic Dirac and polychromatic Titulaer-Glauber quantized field theories (QFTs) of electromagnetism are derived from a photon-energy wave function in much the same way that one derives QFT for electrons, that is, by quantization of a single-particle ... More
The Maxwell wave function of the photonApr 24 2006James Clerk Maxwell unknowingly discovered a correct relativistic, quantum theory for the light quantum, forty-three years before Einstein postulated the photon's existence. In this theory, the usual Maxwell field is the quantum wave function for a single ... More
Nearest-Neighbor Neural Networks for GeostatisticsMar 28 2019Kriging is the predominant method used for spatial prediction, but relies on the assumption that predictions are linear combinations of the observations. Kriging often also relies on additional assumptions such as normality and stationarity. We propose ... More
The Segal-Bargmann transform for compact quotients of symmetric spaces of the complex typeSep 28 2007Sep 29 2010Let G/K be a Riemannian symmetric space of the complex type, meaning that G is complex semisimple and K is a compact real form. Now let {\Gamma} be a discrete subgroup of G that acts freely and cocompactly on G/K. We consider the Segal--Bargmann transform, ... More
Some Koszul properties of standard and irreducible modulesMay 27 2013Let $G$ be a simple, simply connected algebraic group over an algebraically closed field of positive characteristic $p$. In recent work, the authors have studied a graded analogue of the category of rational $G$-modules. These gradings are not natural ... More
The Conformal Sector of F-theory GUTsMar 16 2011Mar 06 2012D3-brane probes of exceptional Yukawa points in F-theory GUTs are natural hidden sectors for particle phenomenology. We find that coupling the probe to the MSSM yields a new class of N = 1 conformal fixed points with computable infrared R-charges. Quite ... More
Slightly Bimetric GravitationJan 16 2001Aug 16 2007The inclusion of a flat metric tensor in gravitation permits the formulation of a gravitational stress-energy tensor and the formal derivation of general relativity from a linear theory in flat spacetime. Building on the works of Kraichnan and Deser, ... More
Structure and mechanism in a second-order statistical state dynamics model of self-sustaining turbulence in plane Couette flowJul 18 2016This paper describes a study of the self-sustaining process (SSP) that maintains turbulence in wall-bounded shear flow. The study uses Couette flow and is based on a statistical state dynamics (SSD) model closed at second order with state variables the ... More
A statistical state dynamics based theory for the formation and equilibration of Saturn's North Polar JetSep 20 2016Coherent jets containing most of the kinetic energy of the flow are a common feature in observations of atmospheric turbulence. In the gaseous planets these jets are maintained by incoherent turbulence excited by small scale convection. Large scale coherent ... More
Log-behavior of two sequences related to the elliptic integralsFeb 13 2016Aug 01 2016Two interesting sequences arose in the study of the series expansions of the complete elliptic integrals, which are called the Catalan-Larcombe-French sequence $\{P_n\}_{n\geq 0}$ and the Fennessey-Larcombe-French sequence $\{V_n\}_{n\geq 0}$ respectively. ... More
Simultaneous Solutions of the Strong CP and Mu ProblemsNov 01 2004Nov 11 2004The \mu parameter of the supersymmetric standard model is replaced by \lambda S, where S is a singlet chiral superfield, introducing a Peccei--Quinn symmetry into the theory. Dynamics at the electroweak scale naturally solves both the strong CP and \mu ... More
Density Perturbations and the Cosmological Constant from Inflationary LandscapesJun 27 2005An anthropic understanding of the cosmological constant requires that the vacuum energy at late time scans from one patch of the universe to another. If the vacuum energy during inflation also scans, the various patches of the universe acquire exponentially ... More
Dimensional Reduction and Vacuum Structure of Quiver Gauge TheoryMay 29 2009Nov 02 2011We describe the structure of the vacuum states of quiver gauge theories obtained via dimensional reduction over homogeneous spaces, in the explicit example of SU(3)-equivariant dimensional reduction of Yang-Mills-Dirac theory on manifolds of the form ... More
Estimating Atmospheric Motion Winds from Satellite Image Data using Space-time Drift ModelsFeb 25 2019Geostationary satellites collect high-resolution weather data comprising a series of images which can be used to estimate wind speed and direction at different altitudes. The Derived Motion Winds (DMW) Algorithm is commonly used to process these data ... More
The Coronal Abundances of Mid-F DwarfsMar 22 2013A Chandra spectrum of the moderately active nearby F6 V star Pi3 Ori is used to study the coronal properties of mid-F dwarfs. We find that Pi3 Ori's coronal emission measure distribution is very similar to those of moderately active G and K dwarfs, with ... More
Vulcan: A Monte Carlo Algorithm for Large Chance Constrained MDPs with Risk Bounding FunctionsSep 04 2018Chance Constrained Markov Decision Processes maximize reward subject to a bounded probability of failure, and have been frequently applied for planning with potentially dangerous outcomes or unknown environments. Solution algorithms have required strong ... More
Quantum state estimation with unknown measurementsJun 27 2013Mar 03 2014Improved measurement techniques are central to technological development and foundational scientific exploration. Quantum optics relies upon detectors sensitive to non-classical features of light, enabling precise tests of physical laws and quantum-enhanced ... More
Two-photon wave mechanicsMay 17 2006Feb 21 2007The position-representation wave function for multi-photon states and its equation of motion are introduced. A major strength of the theory is that it describes the complete evolution (including polarization and entanglement) of multi-photon states propagating ... More
The large radius limit for coherent states on spheresMar 28 2002Apr 27 2002This paper concerns the coherent states on spheres studied by the authors in [J. Math. Phys. 43 (2002), 1211-1236]. We show that in the odd-dimensional case the coherent states on the sphere approach the classical Gaussian coherent states on Euclidean ... More
Reductions in Depth-integrated Picophytoplanktonic Photosynthesis Due to Inhibition by Ultraviolet and Photosynthetically Available Radiation: Global Predictions for $\textit{Prochlorococcus}$ and $\textit{Synechococcus}$Jun 28 2016Phytoplankton photosynthesis in most natural waters is often inhibited by ultraviolet (UV) and intense photosynthetically available radiation (PAR) but the effects on ocean productivity have received little consideration aside from polar areas subject ... More
Competing epidemics on complex networksMay 17 2011Human diseases spread over networks of contacts between individuals and a substantial body of recent research has focused on the dynamics of the spreading process. Here we examine a model of two competing diseases spreading over the same network at the ... More
Coherent states for a 2-sphere with a magnetic fieldDec 06 2011Jan 19 2012We consider a particle moving on a 2-sphere in the presence of a constant magnetic field. Building on earlier work in the nonmagnetic case, we construct coherent states for this system. The coherent states are labeled by points in the associated phase ... More
A Rigourous Treatment of the Lattice Renormalization Problem of F_BAug 05 1992The $B$-meson decay constant can be measured on the lattice using a $1/m_b$ expansion. To relate the physical quantity to Monte Carlo data one has to know the renormalization coefficient, $Z$, between the lattice operators and their continuum counterparts. ... More