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Results for "James C. Weaver"

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Applications of Quantum Annealing in StatisticsApr 15 2019Quantum computation offers exciting new possibilities for statistics. This paper explores the use of the D-Wave machine, a specialized type of quantum computer, which performs quantum annealing. A general description of quantum annealing through the use ... More
Electroporation dynamics for different pore lifetimes based on the standard modelOct 10 2017Standard model of electropration (EP) has long emphasized a single pore lifetime to explain post-pulse transport across cell membranes. However, pore lifetimes estimated from molecular dynamics (MD) models and and those measured from experimental data ... More
Solute transport within single pores post-pulseOct 10 2017We present results of studying the post-pulse transport properties of single pores. Single pores exhibit active transport (drift), and not just passive transport (diffusion) at early post-pulse times. In addition, we suggest experimental design methods ... More
On the area of the symmetry orbits in $T^2$ symmetric spacetimesApr 04 2003Feb 03 2004We obtain a global existence result for the Einstein equations. We show that in the maximal Cauchy development of vacuum $T^2$ symmetric initial data with nonvanishing twist constant, except for the special case of flat Kasner initial data, the area of ... More
Biophysics-based critique of the assisted discharge mechanism hypothesisApr 01 2019Cell experiments with large, short electric field pulses of opposite polarity reveal a remarkable phenomenon: Bipolar cancellation (BPC). Typical defining experiments involve quantitative observation of tracer molecule influx at times of order 100 s post ... More
Broad pore lifetime distributions: A fundamental concept for cell electroporationAug 25 2017We describe a concept that has the potential to change how we think about the underlying mechanisms of cell membrane electroporation (EP). Prior experimental, theoretical and modeling have emphasized a single pore lifetime as adequate for particular conditions. ... More
Nanopore occlusion: A biophysical mechanism for bipolar cancellation in cell membranesJul 03 2018Extraordinarily large but short electric field pulses are reported by many experiments to cause bipolar cancellation (BPC). This unusual cell response occurs if a first pulse is followed by a second pulse with opposite polarity. Possibly universal, BPC ... More
Geometric localization in supported elastic strutsJun 11 2019Localized deformation patterns are a common motif in morphogenesis and are increasingly finding widespread applications in materials science, for instance as memory devices. Here we describe the emergence of spatially localized deformations in a minimal ... More
Oscillatory approach to the singularity in vacuum spacetimes with $T^2$ isometryApr 16 2001May 02 2003We use qualitative arguments combined with numerical simulations to argue that, in the approach to the singularity in a vacuum solution of Einstein's equations with $T^2$ isometry, the evolution at a generic point in space is an endless succession of ... More
Mixmaster Behavior in Inhomogeneous Cosmological SpacetimesDec 12 1997Mar 11 1998Numerical investigation of a class of inhomogeneous cosmological spacetimes shows evidence that at a generic point in space the evolution toward the initial singularity is asymptotically that of a spatially homogeneous spacetime with Mixmaster behavior. ... More
Modules with norms which take values in a C*-algebraDec 19 1996We consider modules E over a C*-algebra A which are equipped with a map into A_+ that has the formal properties of a norm. We completely determine the structure of these modules. In particular, we show that if A has no nonzero commutative ideals then ... More
Are the Nuclei of Seyfert 2 Galaxies Viewed Face-On?Jun 11 1998We show from modeling the Fe Kalpha line in the ASCA spectra of four X-ray bright narrow emission line galaxies (Seyfert types 1.9 and 2) that two equally viable physical models can describe the observed line profile. The first is discussed by Turner ... More
Locally nonconical convexityMay 19 2000There is a hierarchy of structure conditions for convex sets. In this paper we study a recently defined [3, 8, 9] condition called locally nonconical convexity (abbreviated LNC). Is is easy to show that every strictly convex set is LNC, as are half-spaces ... More
The nonlinear Dirac equation in Bose-Einstein condensates: I. Relativistic solitons in armchair nanoribbon optical latticesMay 28 2013Feb 15 2015We present a thorough analysis of soliton solutions to the quasi-one-dimensional nonlinear Dirac equation (NLDE) for a Bose-Einstein condensate in a honeycomb lattice with armchair geometry. Our NLDE corresponds to a quasi-one-dimensional reduction of ... More
The Singularity in Generic Gravitational Collapse Is Spacelike, Local, and OscillatoryMay 17 1998A longstanding conjecture by Belinskii, Khalatnikov, and Lifshitz that the singularity in generic gravitational collapse is spacelike, local, and oscillatory is explored analytically and numerically in spatially inhomogeneous cosmological spacetimes. ... More
The concept of a setMay 11 2009Metaphysical interpretations of set theory are either inconsistent or incoherent. The uses of sets in mathematics actually involve three distinct kinds of collections (surveyable, definite, and heuristic), which are governed by three different kinds of ... More
Quantum graphs as quantum relationsJun 12 2015Dec 27 2015The "noncommutative graphs" which arise in quantum error correction are a special case of the quantum relations introduced in [N. Weaver, Quantum relations, Mem. Amer. Math. Soc. 215 (2012), v-vi, 81-140]. We use this perspective to interpret the Knill-Laflamme ... More
Reasoning about constructive conceptsDec 28 2011Dec 12 2013We find that second order quantification is problematic when a quantified concept variable is supposed to function predicatively. This issue is analyzed and it is shown that a constructive interpretation of the falling under relation suffices to resolve ... More
Intuitionism and the liar paradoxApr 13 2010The concept of informal mathematical proof considered in intuitionism is apparently vulnerable to a version of the liar paradox. However, a careful reevaluation of this concept reveals a subtle error whose correction blocks the contradiction. This leads ... More
Predicativity beyond Gamma_0Sep 11 2005May 11 2009We reevaluate the claim that predicative reasoning (given the natural numbers) is limited by the Feferman-Schutte ordinal Gamma_0. First we comprehensively criticize the arguments that have been offered in support of this position. Then we analyze predicativism ... More
Optimal Pacing for Running 400 m and 800 m Track RacesApr 02 2012Physicists seeking to understand complex biological systems often find it rewarding to create simple "toy models" that reproduce system behavior. Here a toy model is used to understand a puzzling phenomenon from the sport of track and field. Races are ... More
Initial guesses for multi-shift solversOct 07 2008I will present a method for providing initial guesses to a linear solver for systems with multiple shifts. This can also be extended to the case of multiple sources each with a different shift.
Eigenvalue correlations in QCD with a chemical potentialSep 15 2004We discuss a new Random Matrix Model for QCD with a chemical potential that is based on the symmetries of the Dirac operator and can be solved exactly for all eigenvalue correlations for any number of flavors. In the microscopic limit of small energy ... More
Stimulated Radiative Molecular Association in the Early Solar System. II. Orbital Radii of the Planets and Other Satellites of the SunAug 26 2015In a previous investigation, the orbital radii of regular satellites of Uranus, Jupiter, Neptune, and Saturn are shown to be directly related to photon energies in the spectra of atomic and molecular hydrogen. To explain these observations a model was ... More
Catalytic Nucleation of Amyloid Beta and Hen Egg White Fibrils, and p53 OligomerizationMay 06 2016Scaling theory generates transferable (even universal) algebraic and geometrical relations between the amino acid sequences and the aggregation functions of the three titled radically different proteins. In addition to the two hydropathicity scales and ... More
Taste breaking in staggered fermions from random matrix theorySep 17 2003We discuss the construction of a chiral random matrix model for staggered fermions. This model includes $O(a^2)$ corrections to the continuum limit of staggered fermions and is related to the zero momentum limit of the Lee-Sharpe Lagrangian for staggered ... More
Chiral random matrix theory for staggered fermionsApr 24 2012We present a completed random matrix theory for staggered fermions which incorporates all taste symmetry breaking terms at their leading order from the staggered chiral Lagrangian. This is an extension of previous work which only included some of the ... More
On the Duflot filtration for equivariant cohomology rings and applications to group cohomologyNov 15 2017Oct 16 2018We study the Duflot filtration on the Borel equivariant cohomology of smooth manifolds with a smooth $p$-torus action. We axiomatize the filtration and prove analog of several structural results about equivariant cohomology rings in this setting. We apply ... More
A CSO Search for $l$-C$_3$H$^+$: Detection in the Orion Bar PDRMay 27 2014The results of a Caltech Submillimeter Observatory (CSO) search for $l$-C$_3$H$^+$, first detected by Pety et al. (2012) in observations toward the Horsehead photodissociation region (PDR), are presented. A total of 39 sources were observed in the 1 mm ... More
Stimulated Radiative Molecular Association in the Early Solar System: Orbital Radii of Satellites of Uranus, Jupiter, Neptune, and SaturnMay 31 2015The present investigation relates the orbital radii of regular satellites of Uranus, Jupiter, Neptune, and Saturn to photon energies in the spectra of atomic and molecular hydrogen. To explain these observations a model is developed involving stimulated ... More
Hydrogen Spectra, Molecular Association and Orbital Radii in the Solar SystemJul 24 2003A relationship between the average orbital radii of the planets and their satellites in the solar system and the spectra of atomic and molecular hydrogen is identified and investigated. In this model, stimulated radiative association resonances develop ... More
Partially quenched QCD with a chemical potentialOct 02 2006Using a chiral random matrix theory we can now derive the low energy partition functions and Dirac eigenvalue correlations of QCD with different chemical potentials for the dynamical and valence quarks. The results can also be extended to complex (and ... More
The Elemental Shear DynamoSep 01 2011Oct 12 2011A quasi-linear theory is presented for how randomly forced, barotropic velocity fluctuations cause an exponentially-growing, large-scale (mean) magnetic dynamo in the presence of a uniform shear flow, $\vec{U} = S x \vec{e}_y$. It is a "kinematic" theory ... More
Quantum relationsMay 03 2010We define a "quantum relation" on a von Neumann algebra M \subset B(H) to be a weak* closed operator bimodule over its commutant M'. Although this definition is framed in terms of a particular representation of M, it is effectively representation independent. ... More
On the unique predual problem for Lipschitz spacesNov 06 2016Nov 09 2016For any metric space X, the predual of Lip(X) is unique. If X has finite diameter or is complete and convex --- in particular, if it is a Banach space --- then the predual of Lip_0(X) is unique.
Operator algebras associated with the Klein-Gordon position representation in relativistic quantum mechanicsSep 07 2002We initiate a mathematically rigorous study of Klein-Gordon position operators in single-particle relativistic quantum mechanics. Although not self-adjoint, these operators have real spectrum and enjoy a limited form of spectral decomposition. The associated ... More
The Kadison-Singer problem in discrepancy theorySep 07 2002We give a combinatorial form of the Kadison-Singer problem, a famous problem in C*-algebra. This combinatorial problem, which has several minor variations, is a discrepancy question about vectors in C^n. Some partial results can be easily deduced from ... More
The Kadison-Singer problem in discrepancy theory, IIMar 11 2013We apply Srivastava's spectral sparsification technique to a vector balancing version of the Kadison-Singer problem. The result is a one-sided version of the conjectured solution.
Staggered chiral random matrix theoryDec 21 2010Jun 02 2011We present a random matrix theory (RMT) for the staggered lattice QCD Dirac operator. The staggered RMT is equivalent to the zero-momentum limit of the staggered chiral Lagrangian and includes all taste breaking terms at their leading order. This is an ... More
How to Find More Supernovae with Less Work: Object Classification Techniques for Difference ImagingMay 03 2007We present the results of applying new object classification techniques to difference images in the context of the Nearby Supernova Factory supernova search. Most current supernova searches subtract reference images from new images, identify objects in ... More
The semantic conception of proofDec 28 2011Dec 12 2013We analyze the informal semantic conception of proof and axiomatize the proof relation and the provability operator. A self referential propositional calculus which admits provable liar type sentences is introduced and proven consistent. We also investigate ... More
Sub-Riemannian metrics for quantum Heisenberg manifoldsJan 05 1998Every Heisenberg manifold has a natural "sub-Riemannian" metric with interesting properties. We describe the corresponding noncommutative metric structure for Rieffel's quantum Heisenberg manifolds.
The Local Lifting Problem for $D_4$Jun 12 2017Jun 23 2017For a prime $p$, a cyclic-by-$p$ group $G$ and a $G$-extension $L|K$ of complete discrete valuation fields of characteristic $p$ with algebraically closed residue field, the local lifting problem asks whether the extension $L|K$ lifts to characteristic ... More
Set theory and C*-algebrasApr 09 2006We survey the use of extra-set-theoretic hypotheses, mainly the continuum hypothesis, in the C*-algebra literature. The Calkin algebra emerges as a basic object of interest.
The effects of surface roughness on lunar Askaryan pulsesAug 25 2016The effects of lunar surface roughness, on both small and large scales, on Askaryan radio pulses generated by particle cascades beneath the lunar surface has never been fully estimated. Surface roughness affects the chances of a pulse escaping the lunar ... More
Universal results from an alternate random matrix model for QCD with a baryon chemical potentialMar 11 2004We introduce a new non-Hermitian random matrix model for QCD with a baryon chemical potential. This model is a direct chiral extension of a previously studied model that interpolates between the Wigner-Dyson and Ginibre ensembles. We present exact results ... More
Log-Lipschitz embeddings of homogeneous sets with sharp logarithmic exponents and slicing the unit cubeJul 26 2010If $X$ is a subset of a Banach space with $X-X$ homogeneous, then $X$ can be embedded into some $\R^n$ (with $n$ sufficiently large) using a linear map $L$ whose inverse is Lipschitz to within logarithmic corrections. More precisely, $$c\,\frac{\|x-y\|}{|\,\log\|x-y\|\,|^\alpha}\le|Lx-Ly|\le ... More
Paradoxes of rational agency and formal systems that verify their own soundnessDec 12 2013Dec 21 2013We consider extensions of Peano arithmetic which include an assertibility predicate. Any such system which is arithmetically sound effectively verifies its own soundness. This leads to the resolution of a range of paradoxes involving rational agents who ... More
Kinds of conceptsDec 28 2011The central focus is on clarifying the distinction between sets and proper classes. To this end we identify several categories of concepts (surveyable, definite, indefinite), and we attribute the classical set theoretic paradoxes to a failure to appreciate ... More
Constructive truth and circularityMay 11 2009Apr 13 2010We propose a constructive interpretation of truth which resolves the standard semantic paradoxes.
Axiomatizing mathematical conceptualism in third order arithmeticMay 11 2009We review the philosophical framework of mathematical conceptualism as an alternative to set-theoretic foundations and show how mainstream mathematics can be developed on this basis. The paper includes an explicit axiomatization of the basic principles ... More
A "quantum" Ramsey theorem for operator systemsJan 03 2016Jan 13 2016Let V be a linear subspace of M_n(C) which contains the identity matrix and is stable under the formation of Hermitian adjoints. We prove that if n is sufficiently large then there exists a rank k orthogonal projection P such that dim(PVP) = 1 or k^2. ... More
Analysis in J_2Sep 11 2005Sep 12 2005This is an expository paper in which I explain how core mathematics, particularly abstract analysis, can be developed within a concrete countable set J_2 (the second set in Jensen's constructible hierarchy). The implication, well-known to proof theorists ... More
Lipschitz algebras and derivations II: exterior differentiationJul 17 1998Basic aspects of differential geometry can be extended to various non-classical settings: Lipschitz manifolds, rectifiable sets, sub-Riemannian manifolds, Banach manifolds, Weiner space, etc. Although the constructions differ, in each of these cases one ... More
The Persistent Activity of Jupiter-Family Comets at 3 to 7 AUApr 13 2013We present an analysis of comet activity based on the Spitzer Space Telescope component of the Survey of the Ensemble Physical Properties of Cometary Nuclei. We show that the survey is well suited to measuring the activity of Jupiter-family comets at ... More
Is set theory indispensable?May 11 2009Although Zermelo-Fraenkel set theory (ZFC) is generally accepted as the appropriate foundation for modern mathematics, proof theorists have known for decades that virtually all mainstream mathematics can actually be formalized in much weaker systems which ... More
Hilbert bimodules with involutionAug 23 1999We examine Hilbert bimodules which possess a (generally unbounded) involution. Topics considered include a linking algebra representation, duality, locality, and the role of these bimodules in noncommutative differential geometry.
Truth and the liar paradoxDec 28 2011We analyze the informal notion of truth and conclude that it can be formalized in essentially two distinct ways: constructively, in terms of provability, or classically, as a hierarchy of concepts which satisfy Tarski's biconditional in limited settings. ... More
Mathematical conceptualismSep 11 2005Sep 12 2005This is an explanation and defense of "mathematical conceptualism" for a general mathematical and philosophical audience. I make a case that it is cogent, rigorous, attractive, and better suited to ordinary mathematical practice than all other foundational ... More
Quantum graphs as quantum relationsJun 12 2015Jun 28 2017The "noncommutative graphs" which arise in quantum error correction are a special case of the quantum relations introduced in [N. Weaver, Quantum relations, Mem. Amer. Math. Soc. 215 (2012), v-vi, 81-140]. We use this perspective to interpret the Knill-Laflamme ... More
Classical curves via one-vertex mapsJan 08 2012Jul 16 2012One-vertex maps (a type of dessin d'enfant) give a uniform characterization of certain well-known algebraic curves, including those of Klein, Wiman, Accola-Maclachlan and Kulkarni. The characterization depends on a new classification of one-vertex (dually, ... More
A prime C*-algebra that is not primitiveJun 28 2001Jul 06 2001We construct a non-separable C*-algebra that is prime but not primitive.
Set theory and cyclic vectorsFeb 25 2002Let H be a separable, infinite dimensional Hilbert space and let S be a countable subset of H. Then most positive operators on H have the property that every nonzero vector in the span of S is cyclic, in the sense that the set of operators in the positive ... More
A counterexample to a conjecture of Akemann and AndersonMay 22 2001Akemann and Anderson made a conjecture about ``paving'' projections in finite dimensional matrix algebras which, if true, would settle the well-known Kadison-Singer problem. We falsify their conjecture by an explicit seqence of counterexamples.
Quantifying Kinematic Substructure in the Milky Way's Stellar HaloNov 08 2010Aug 03 2011We present and analyze the positions, distances, and radial velocities for over 4000 blue horizontal-branch (BHB) stars in the Milky Way's halo, drawn from SDSS DR8. We search for position-velocity substructure in these data, a signature of the hierarchical ... More
Recent progress in understanding the hot and warm gas phases in the halos of star-forming galaxiesJul 08 2002In this contribution we present a few selected examples of how the latest generation of space-based instrumentation -- NASA's Chandra X-ray Observatory and the Far-Ultraviolet Spectroscopic Explorer (FUSE) -- are finally answering old questions about ... More
Overview of the New Horizons Science PayloadSep 26 2007The New Horizons mission was launched on 2006 January 19, and the spacecraft is heading for a flyby encounter with the Pluto system in the summer of 2015. The challenges associated with sending a spacecraft to Pluto in less than 10 years and performing ... More
A Close-up View of the Young Circumbinary Disk HD 142527Apr 03 2017We present ALMA observations of the 0.88 millimeter dust continuum, 13CO, and C18O J=3-2 line emission of the circumbinary disk HD142527 at a spatial resolution of about 0.25". This system is characterized by a large central cavity of roughly 120 AU in ... More
The First Detection of [O IV] from an Ultraluminous X-ray Source with Spitzer I. Observational Results for Holmberg II ULXApr 12 2009We present the first Spitzer Infrared Spectrograph (IRS) observations of the [O IV] 25.89 $\mu$m emission line detected from the ultraluminous X-ray source (ULX) in Holmberg II. This line is a well established signature of high ionization, usually associated ... More
Chandra observations of NGC 253. II: On the origin of diffuse X-ray emission in the halos of starburst galaxiesNov 27 2001We present a detailed case study of the diffuse X-ray and H-alpha emission in the halo of NGC 253, a nearby edge-on starburst galaxy driving a galactic superwind. The arcsecond spatial resolution of the Chandra ACIS instrument allows us to study the spatial ... More
Probing Unification With Chandra HETGS and XMM-Newton EPIC And RGS Spectroscopy of the Narrow Emission Line Galaxy NGC 2110Aug 30 2007We present results from Chandra HETGS (250 ks over two epochs) and XMM-Newton EPIC and RGS (60 ks) observations of NGC 2110, which has been historically classified as a Narrow Emission Line Galaxy galaxy. Our results support the interpretation that the ... More
A high spatial resolution X-ray and H-alpha study of hot gas in the halos of star-forming disk galaxies. I. Spatial and spectral properties of the diffuse X-ray emissionJun 27 2003Jan 14 2004We present arcsecond resolution Chandra X-ray and ground-based optical H-alpha imaging of a sample of ten edge-on star-forming disk galaxies (seven starburst and three ``normal'' spiral galaxies), a sample which covers the full range of star-formation ... More
The Origin and Kinematics of Cold Gas in Galactic Winds: Insight from Numerical SimulationsMar 19 2008Apr 02 2009We study the origin of Na I absorbing gas in ultraluminous infrared galaxies motivated by the recent observations by Martin of extremely superthermal linewidths in this cool gas. We model the effects of repeated supernova explosions driving supershells ... More
The First Detection of [O IV] from an Ultraluminous X-ray Source with Spitzer. II. Evidence for High Luminosity in Holmberg II ULXSep 28 2009This is the second of two papers examining Spitzer Infrared Spectrograph (IRS) observations of the ultraluminous X-ray source (ULX) in Holmberg II. Here we perform detailed photoionization modeling of the infrared lines. Our analysis suggests that the ... More
A high spatial resolution X-ray and H-alpha study of hot gas in the halos of star-forming disk galaxies. II. Quantifying supernova feedbackJun 27 2003Jan 27 2004We investigate how the empirical properties of hot X-ray-emitting gas in a sample of seven starburst and three normal edge-on spiral galaxies (a sample which covers the full range of star-formation intensity found in disk galaxies) correlate with the ... More
Warm absorber, reflection and Fe K line in the X-ray spectrum of IC 4329AOct 12 1995Results from the X-ray spectral analysis of the ASCA PV phase observation of the Seyfert 1 galaxy IC 4329A are presented. We find that the 0.4 - 10 keV spectrum of IC 4329A is best described by the sum of a steep ($\Gamma \sim 1.98$) power-law spectrum ... More
Role of oxygen in the electron-doped superconducting cupratesFeb 06 2006We report on resistivity and Hall measurements in thin films of the electron-doped superconducting cuprate Pr$_{2-x}$Ce$_{x}$CuO$_{4\pm\delta}$. Comparisons between x = 0.17 samples subjected to either ion-irradiation or oxygenation demonstrate that changing ... More
Testing the Paradigm that Ultraluminous X-ray Sources as a Class Represent Accreting Intermediate-Mass Black HolesJul 09 2008Sep 12 2008To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting intermediate-mass black holes (IMBHs), we have undertaken a program to identify ULXs and a lower luminosity X-ray comparison sample with the highest ... More
X-ray Emission from the Prototypical LINER Galaxy NGC 1052Feb 18 1999We examine the 0.1 to 10.0 keV X-ray spectrum of the bright nuclear LINER galaxy NGC 1052, one of two elliptical galaxies known to contain a luminous H2O maser. The observed 2.0-10.0 keV spectrum is unusually flat (photon index Gamma~0.2) and best described ... More
Thermodynamic Stability of Mg-based Ternary Long-Period Stacking Ordered StructuresSep 12 2013Mg alloys containing long-period stacking ordered (LPSO) structures exhibit remarkably high tensile yield strength and ductility. They have been found in a variety of ternary Mg systems of the general form Mg-XL-XS, where XL and XS are elements larger ... More
Structure and Function of Window Glass and PyrexAug 07 2006Sep 11 2006Window glass is a ternary mixture, while pyrex (after window glass, the most common form of commercial glass) is a quaternary. Building on our previous success in deriving the composition of window glass (sodium calcium silicate) without adjustable parameters, ... More
Higher-Dimensional Algebra III: n-Categories and the Algebra of OpetopesFeb 10 1997We give a definition of weak n-categories based on the theory of operads. We work with operads having an arbitrary set S of types, or `S-operads', and given such an operad O, we denote its set of operations by elt(O). Then for any S-operad O there is ... More
Kosterlitz-Thouless Universality in a Fermionic SystemSep 22 2001A new extension of the attractive Hubbard model is constructed to study the critical behavior near a finite temperature superconducting phase transition in two dimensions using the recently developed meron-cluster algorithm. Unlike previous calculations ... More
A simple proof of uniqueness of the particle trajectories for solutions of the Navier-Stokes equationsOct 30 2007Feb 15 2011We give a simple proof of the uniqueness of fluid particle trajectories corresponding to: 1) the solution of the two-dimensional Navier Stokes equations with an initial condition that is only square integrable, and 2) the local strong solution of the ... More
The motion of a fluid-rigid disc system at the zero limit of the rigid disc radiusFeb 15 2011We consider the two-dimensional motion of the coupled system of a viscous incompressible fluid and a rigid disc moving with the fluid, in the whole plane. The fluid motion is described by the Navier-Stokes equations and the motion of the rigid body by ... More
Supersolutions for a class of semilinear heat equationsNov 01 2011Jan 30 2012A semilinear heat equation $u_{t}=\Delta u+f(u)$ with nonnegative initial data in a subset of $L^{1}(\Omega)$ is considered under the assumption that $f$ is nonnegative and nondecreasing and $\Omega\subseteq \R^{n}$. A simple technique for proving existence ... More
Amorphous Dynamic Partial Reconfiguration with Flexible Boundaries to Remove FragmentationOct 23 2017Oct 24 2017Dynamic partial reconfiguration (DPR) allows one region of an field-programmable gate array (FPGA) fabric to be reconfigured without affecting the operations on the rest of the fabric. To use an FPGA as a dynamically shared compute resource, one could ... More
Modeling Traffic Networks Using Integrated Route and Link DataNov 04 2018Real-time navigation services, such as Google Maps and Waze, are widely used in daily life. These services provide rich data resources in real-time traffic conditions and travel time predictions; however, they have not been fully applied in transportation ... More
From Finite Sets to Feynman DiagramsApr 20 2000`Categorification' is the process of replacing equations by isomorphisms. We describe some of the ways a thoroughgoing emphasis on categorification can simplify and unify mathematics. We begin with elementary arithmetic, where the category of finite sets ... More
Oxygen Channels and Fractal Wave-Particle Duality in the Evolution of Myoglobin and NeuroglobinMar 20 2016The evolution of terrestrial and aquatic wild type (WT) globins is dominated by changes in two proximate - distal Histidine ligand exit channels, here monitored quantitatively by hydropathic waves. These waves reveal allometric functional features inaccessible ... More
Using Vivado-HLS for Structural Design: a NoC Case StudyOct 27 2017There have been ample successful examples of applying Xilinx Vivado's "function-to-module" high-level synthesis (HLS) where the subject is algorithmic in nature. In this work, we carried out a design study to assess the effectiveness of applying Vivado-HLS ... More
Introduction to the Transverse Spatial Correlations in Spontaneous Parametric Down-Conversion through the Biphoton Birth ZoneFeb 24 2015Feb 27 2018As a tutorial to the spatial aspects of Spontaneous Parametric Downconversion (SPDC), we present a detailed first-principles derivation of the transverse correlation width of photon pairs in degenerate collinear SPDC. This width defines the size of a ... More
Asymptotic expansion of the lattice scalar propagator in coordinate spaceMay 22 1998Dec 16 1998The asymptotic expansion of the massive scalar field propagator on a n-dimensional lattice is derived. The method used is based on the evaluation of the asymptotic expansion of the modified Bessel function $I_{\nu}(\nu^{2} \beta)$ as the order $\nu$ grows ... More
Dirac eigenvalue correlations in quenched QCD at finite densityOct 27 2005We compare eigenvalue correlations of the Dirac operator with a chemical potential obtained from lattice simulations of quenched QCD with analytic predictions obtained from chiral effective theories in the zero-momentum limit. By comparing the density ... More
Ballistic Conductance in Oxidized Si NanowiresFeb 02 2010The influence of local oxidation in silicon nanowires on hole transport, and hence the effect of varying the oxidation state of silicon atoms at the wire surface, is studied using density functional theory in conjunction with a Green's function scattering ... More
Critical Behavior of a Chiral Condensate with a Meron Cluster AlgorithmOct 20 2000A new meron cluster algorithm is constructed to study the finite temperature critical behavior of the chiral condensate in a $(3+1)$ dimensional model of interacting staggered fermions. Using finite size scaling analysis the infinite volume condensate ... More
An a posteriori condition on the numerical approximations of the Navier-Stokes equations for the existence of a strong solutionJan 12 2007In their 2006 paper, Chernyshenko et al prove that a sufficiently smooth strong solution of the 3d Navier-Stokes equations is robust with respect to small enough changes in initial conditions and forcing function. They also show that if a regular enough ... More
Time-Shared Execution of Realtime Computer Vision Pipelines by Dynamic Partial ReconfigurationMay 26 2018Jun 21 2018This paper presents an FPGA runtime framework that demonstrates the feasibility of using dynamic partial reconfiguration (DPR) for time-sharing an FPGA by multiple realtime computer vision pipelines. The presented time-sharing runtime framework manages ... More
Progress on ELROI satellite license plate flight prototypesApr 02 2018The Extremely Low-Resource Optical Identifier (ELROI) beacon is a concept for a milliwatt optical "license plate" that can provide unique ID numbers for everything that goes into space. Using photon counting to enable extreme background rejection in real ... More
Astrometric observations of X-ray binaries using very long baseline interferometryJan 24 2014Feb 20 2014I review the astrophysical insights arising from high-precision astrometric observations of X-ray binary systems, focussing primarily (but not exclusively) on recent results with very long baseline interferometry. Accurate, model-independent distances ... More