Results for "Paul Beard"

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Enhancing Compressed Sensing Photoacoustic Tomography by Simultaneous Motion EstimationFeb 14 2018A crucial limitation of current high-resolution 3D photoacoustic tomography (PAT) devices that employ sequential scanning is their long acquisition time. In previous work, we demonstrated how to use compressed sensing techniques to improve upon this: ... More
Model based learning for accelerated, limited-view 3D photoacoustic tomographyAug 31 2017Recent advances in deep learning for tomographic reconstructions have shown great potential to create accurate and high quality images with a considerable speed-up. In this work we present a deep neural network that is specifically designed to provide ... More
Acoustic Wave Field Reconstruction from Compressed Measurements with Application in Photoacoustic TomographySep 09 2016We present a method for the recovery of compressively sensed acoustic fields using patterned, instead of point-by-point, detection. From a limited number of such compressed measurements, we propose to reconstruct the field on the sensor plane in each ... More
Accelerated High-Resolution Photoacoustic Tomography via Compressed SensingApr 30 2016Sep 28 2016Current 3D photoacoustic tomography (PAT) systems offer either high image quality or high frame rates but are not able to deliver high spatial and temporal resolution simultaneously, which limits their ability to image dynamic processes in living tissue. ... More
The first direct measurement of 12C(12C,n)23Mg at stellar energiesJul 14 2015Neutrons produced by the carbon fusion reaction 12C(12C,n)23Mg play an important role in stellar nucleosynthesis. However, past studies have shown large discrepancies between experimental data and theory, leading to an uncertain cross section extrapolation ... More
Multiple Extended Target Tracking with Labelled Random Finite SetsJul 27 2015Targets that generate multiple measurements at a given instant in time are commonly known as extended targets. These present a challenge for many tracking algorithms, as they violate one of the key assumptions of the standard measurement model. In this ... More
Measurement of the 33S(α,p)36Cl cross section: Implications for production of 36Cl in the early Solar SystemOct 10 2013Short-lived radionuclides (SLRs) with lifetimes \tau < 100 Ma are known to have been extant when the Solar System formed over 4.5 billion years ago. Identifying the sources of SLRs is important for understanding the timescales of Solar System formation ... More
New Experimental limit on Optical Photon Coupling to Neutral, Scalar BosonsJun 16 2008We report on the first results of a sensitive search for scalar coupling of photons to a light neutral boson in the mass range of approximately 1.0 milli-electron volts and coupling strength greater than 10$^-6$ GeV$^-1$ using optical photons. This was ... More
Metabolic Futile Cycles and Their Functions: A Systems Analysis of Energy and ControlNov 04 2005Jun 14 2006It has long been hypothesized that futile cycles in cellular metabolism are involved in the regulation of biochemical pathways. Following the work of Newsholme and Crabtree, we develop a quantitative theory for this idea based on open-system thermodynamics ... More
Relationship between Thermodynamic Driving Force and One-Way Fluxes in Reversible Chemical ReactionsJul 14 2006Nov 22 2006Chemical reaction systems operating in nonequilibrium open-system states arise in a great number of contexts, including the study of living organisms, in which chemical reactions, in general, are far from equilibrium. Here we introduce a theorem that ... More
Specification, Construction, and Exact Reduction of State Transition System Models of Biochemical ProcessesMar 15 2012Biochemical reaction systems may be viewed as discrete event processes characterized by a number of states and state transitions. These systems may be modeled as state transition systems with transitions representing individual reaction events. Since ... More
Directionality is an inherent property of biochemical networksJan 02 2007Feb 01 2007Thermodynamic constraints on reactions directions are inherent in the structure of a given biochemical network. However, concrete procedures for determining feasible reaction directions for large-scale metabolic networks are not well established. This ... More
Simulations of Discrete Quantum Systems in Continuous Euclidean TimeFeb 29 1996Path integrals are usually formulated in discrete Euclidean time using the Trotter formula. We propose a new method to study discrete quantum systems, in which we work directly in the Euclidean time continuum. The method is of general interest and can ... More
An Overview of Particle Methods for Random Finite Set ModelsFeb 12 2016This overview paper describes the particle methods developed for the implementation of the a class of Bayes filters formulated using the random finite set formalism. It is primarily intended for the readership already familiar with the particle methods ... More
The dynamics of domain wall SkyrmionsMay 13 2013It has recently been shown that Skyrmions with a fixed size can exist in theories without a Skyrme term, providing the Skyrmion is located on a domain wall. Here we numerically compute domain wall Skyrmions of this type, in a (2+1)-dimensional O(3) sigma ... More
Run Time Approximation of Non-blocking Service Rates for Streaming SystemsApr 02 2015Apr 13 2015Stream processing is a compute paradigm that promises safe and efficient parallelism. Modern big-data problems are often well suited for stream processing's throughput-oriented nature. Realization of efficient stream processing requires monitoring and ... More
Automorphisms of $\mathscr{P}(λ)/\mathscr{I}_κ$Jun 10 2015Aug 27 2015We study conditions on automorphisms of Boolean algebras of the form $P(\lambda)/I_\kappa$ (where $\lambda$ is an uncountable cardinal and $I_\kappa$ is the ideal of sets of cardinality less than $\kappa$) which allow one to conclude that a given automorphism ... More
The Visible and Infrared Survey Telescope for Astronomy (VISTA): Design, Technical Overview and PerformanceSep 16 2014Mar 11 2015The Visible and Infrared Survey Telescope for Astronomy (VISTA) is the 4-metre wide-field survey telescope at ESO's Paranal Observatory, equipped with the world's largest near-infrared imaging camera (VISTA IR Camera, VIRCAM), with 1.65 degree diameter ... More
Generating functions attached to some infinite matricesJun 10 2009Let V be an infinite matrix with rows and columns indexed by the positive integers, and entries in a field F. Suppose that v_{i,j} only depends on i-j and is 0 for |i-j| large. Then V^n is defined for all n, and one has a "generating function" G=\sum ... More
It was twenty years ago today ...Aug 14 2011Sep 13 2011To mark the 20th anniversary of the (14 Aug 1991) commencement of hep-th@xxx.lanl.gov (now arXiv.org), I've adapted this article from one that first appeared in Physics World (2008), was later reprinted (with permission) in Learned Publishing (2009), ... More
Exponentiation of commuting nilpotent varietiesJun 22 2013Sep 20 2014Let $H$ be a linear algebraic group over an algebraically closed field of characteristic $p>0$. We prove that any "exponential map" for $H$ induces a bijection between the variety of $r$-tuples of commuting $[p]$-nilpotent elements in $Lie(H)$ and the ... More
Support Varieties for Frobenius Kernels of Classical GroupsJan 13 2012Sep 26 2012Let G be a simple classical algebraic group over an algebraically closed field of positive characteristic. We describe the support variety of a simple G-module over the r-th Frobenius kernel of G, in terms of its calculation over the first Frobenius kernel. ... More
Topological fundamental groups can distinguish spaces with isomorphic homotopy groupsFeb 18 2005Apr 19 2005We exhibit a map f between aspherical spaces X and Y such that f induces an isomorphism on homotopy groups but, with natural topologies, X and Y fail to have homeomorphic fundamental groups. Thus the topological fundamental group has the capacity to distinguish ... More
Compactly generated quasitopological homotopy groups with discontinuous multiplicationMay 31 2011For each positive integer Q there exists a path connected metric compactum X such that the Qth-homotopy group of X is compactly generated but not a topological group (with the quotient topology).
Just How Final are Today's Quantum Structures?Mar 26 2001I present a selection of conceptual and mathematical problems in the foundations of modern physics as they derive from the title question. Contribution to a panel session, "Springer Forum: Quantum Structures -- Physical, Mathematical and Epistemological ... More
The Hawaiian earring group and metrizabilityMar 10 2006Endowed with quotient topology inherited from the space of based loops, the fundamental group of the Hawaiian earring fails to be metrizable. The fundamental group of any space which retracts to the Hawaiian earring is also nonmetrizable.
Absolute Algebra III - The saturated spectrumOct 31 2013Let B1 denote the set {0,1} with the usual operations except that $1+1=1$, in other words, the smallest characteristic 1 semifield . We compare two possible analogues of the notion of prime ideal for B1--algebras. We then consider the relations between ... More
Algèbre absolueNov 10 2009We give an exposition of Zhu's theory concerning a formal analogue of the field Fp, "for p = 1", and then compare it to Deitmar's.-- Nous exposons la th\'eorie de Zhu concernant un analogue formel du corps Fp "pour p = 1", et la comparons \`a celle de ... More
Qualitative Decision Making Under Possibilistic Uncertainty: Toward more discriminating criteriaJul 04 2012The aim of this paper is to propose a generalization of previous approaches in qualitative decision making. Our work is based on the binary possibilistic utility (PU), which is a possibilistic counterpart of Expected Utility (EU).We first provide a new ... More
The Evolution of AGN in Groups and ClustersOct 08 2009The evolution of AGN in groups and clusters provides important information about how their black holes grow, the extent to which galaxies and black holes coevolve in dense environments, and has implications for feedback in the local universe and at the ... More
Showing OCA in Pmax-style extensionsNov 09 1999We give a proof that OCA holds in the Pmax extension of L(R). The proof is general enough to be adapted to most Pmax variations.
Symplectic packing in dimension 4Jun 06 1996Jun 09 1996We discuss closed symplectic 4-manifolds which admit full symplectic packings by $N$ equal balls for large $N$'s. We give a homological criterion for recognizing such manifolds. As a corollary we prove that ${\Bbb C}P^2$ can be fully packed by $N$ equal ... More
Jets via Hasse-Schmidt DerivationsJul 07 2004Jan 09 2013This note is intended to provide a general reference for jet spaces and jet differentials, valid in maximal generality (at the level of EGA). The approach is rather concrete, using Hasse-Schmidt (divided) higher differentials. Discussion of projectivized ... More
Noncommutative String Theory, the R-Matrix, and Hopf AlgebrasNov 04 1999Motivated by the form of the noncommutative *-product in a system of open strings and Dp-branes with constant nonzero Neveu-Schwarz 2-form, we define a deformed multiplication operation on a quasitriangular Hopf algebra in terms of its R-matrix, and comment ... More
Ward Identities and Anomalies in Pure W_4 GravitySep 11 1998Feb 12 1999W_4 gravity is treated algebraically, represented by a set of transformations on classical fields. The Ward identities of the theory are determined by requiring the algebra to close. The general forms for the anomalies are found by looking for solutions ... More
Derivatives and the Role of the Drinfel'd Twist in Noncommutative String TheoryMar 26 2000Mar 29 2000We consider the derivatives which appear in the context of noncommutative string theory. First, we identify the correct derivations to use when the underlying structure of the theory is a quasitriangular Hopf algebra. Then we show that this is a specific ... More
Effects of mathematical locality and number scaling on coordinate chart useMay 13 2014A stronger foundation for earlier work on the effects of number scaling, and local mathematics is described. Emphasis is placed on the effects of scaling on coordinate systems. Effects of scaling are represented by a scalar field, $\theta,$ that appears ... More
Fields of Iterated Quantum Reference Frames based on Gauge Transformations of Rational String StatesApr 18 2006This work is based on a description of quantum reference frames that seems more basic than others in the literature. Here a frame is based on a set of real and of complex numbers and a space time as a 4-tuple of the real numbers. There are many isomorphic ... More
A representation of complex rational numbers in quantum mechanicsMar 16 2005Jun 20 2005A representation of complex rational numbers in quantum mechanics is described that is not based on logical or physical qubits. It stems from noting that the zeros in a product qubit state do not contribute to the number. They serve only as place holders. ... More
Tightening the Theory-Experiment Connection in Physics: R_{n} based Space and TimeAug 11 2004Some aspects of replacing C based physics by C_{n} based physics are discussed. Here C_{n} ={R_{n},I_{n}} where R_{n} and I_{n} are the real and imaginary components of the numbers in C_{n}, and both R_{n} and I_{n}) are sets of length 2n string numbers ... More
The Representation of Numbers by States in Quantum MechanicsSep 29 2000The representation of numbers by tensor product states of composite quantum systems is examined. Consideration is limited to k-ary representations of length L and arithmetic modulo k^{L}. An abstract representation on an L fold tensor product Hilbert ... More
Dynamics of Induced Surfaces in Four-Dimensional Euclidean SpaceDec 15 2006The Davey Stewartson hierarchy will be developed based on a set of three matrix differential operators. These equations will act as evolution equations for different types of surface deformation in Euclidean four space. The Weierstrass representation ... More
Closed Unitary and Similarity Orbits of Normal Operators in Purely Infinite C*-AlgebrasAug 31 2012Nov 29 2012We will investigate the norm closure of the unitary and similarity orbits of normal operators in unital, simple, purely infinite C*-algebras. An operator theoretic proof will be given to the classification of when two normal operators are approximately ... More
Cyclic MonopolesOct 06 1996We study charge k SU(2) BPS monopoles which are symmetric under the cyclic group of order k. Approximate twistor data (spectral curves and Nahm data) is constructed using a new technique based upon a Painleve analysis of Nahm's equation around a pole. ... More
Knots in the Skyrme-Faddeev modelMay 10 2007The Skyrme-Faddeev model is a modified sigma model in three-dimensional space, which has string-like topological solitons classified by the integer-valued Hopf charge. Numerical simulations are performed to compute soliton solutions for Hopf charges up ... More
Kink Chains from Instantons on a TorusSep 29 1994We describe how the procedure of calculating approximate solitons from instanton holonomies may be extended to the case of soliton crystals. It is shown how sine-Gordon kink chains may be obtained from CP1 instantons on a torus. These kink chains turn ... More
Spanning Trees in Grid GraphsSep 15 2008Building on work by Desjarlais, Molina, Faase, and others, a general method is obtained for counting the number of spanning trees of graphs that are a product of an arbitrary graph and either a path or a cycle, of which grid graphs are a subclass. Results ... More
Analyticity of strictly static and strictly stationary, inheriting and non-inheriting Einstein-Maxwell solutionsApr 19 2007Following the technique of M\"uller-zum-Hagen, refs [1,2], we show that strictly static and strictly stationary solutions of the Einstein-Maxwell equations are analytic in harmonic coordinates. This holds whether or not the Maxwell field inherits the ... More
A comment on positive mass for scalar field sourcesMay 31 2011We use a transformation due to Bekenstein to relate the ADM and Bondi masses of asymptotically-flat solutions of the Einstein equations with, respectively, scalar sources and conformal-scalar sources. Although the conformal-scalar energy-momentum tensor ... More
Conditions for nonexistence of static or stationary, Einstein-Maxwell, non-inheriting black-holesNov 05 2006We consider asymptotically-flat, static and stationary solutions of the Einstein equations representing Einstein-Maxwell space-times in which the Maxwell field is not constant along the Killing vector defining stationarity, so that the symmetry of the ... More
A Note on Riemannian Anti-self-dual Einstein metrics with SymmetrySep 11 2006We give a complete proof of the result stated in an earlier article, that the general Einstein metric with a symmetry, an anti-self-dual Weyl tensor and nonzero scalar curvature is determined by a solution of the $SU(\infty)$-Toda field equation. We consider ... More
Two linear transformations each tridiagonal with respect to an eigenbasis of the otherJun 27 2004Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V\to V$ and $A^*:V\to V$ that satisfy both conditions below: (i) There exists a basis for $V$ with respect ... More
GL(2,R)-Invariant Measures in Marked Strata: Generic Marked Points, Earle-Kra for Strata, and IlluminationJan 28 2016Let H be a component of a stratum of abelian differentials and let H(m,n) be the collection of translation surfaces in H together with m+n distinct marked points, none coinciding with zeros, m of which are labelled and n of which are unlabelled. We show ... More
On Integrability of Type 0A Matrix Model in the Presence of D braneJan 11 2011We consider type 0A matrix model in the presence of a spacelike D brane,localized in matter direction at any arbitrary point. It appears that in order to have an appropriate string/MQM correspondence we must need to impose a constraint on the matrix model ... More
Right submodules of finite rank for von Neumann dynamical systemsSep 03 2010Jan 10 2011Let $(M,\tau,\sigma,\Gamma)$ be a (finite) von Neumann dynamical system and let $N$ be a $\Gamma$-invariant unital von Neumann subalgebra of $M$. If $V\subset L^2(M)$ is a right $N$-submodule whose projection $p_V$ has finite trace in $< M,e_N>$ and is ... More
Parton Propagation in a Gluon FieldFeb 22 2005The phenomenological success of PQCD is based on processes where the effects of the color field environment on parton propagation can be eliminated or is universal. In hard diffraction and quarkonium production the PQCD subprocess is the same as in fully ... More
The Unexpected Role of Final State Interactions in Deep Inelastic ScatteringJul 21 2003Rescattering of the struck quark in Deep Inelastic Scattering implies that measured parton distributions are not directly related to the Fock state probabilities of the target wave function. The production amplitudes acquire dynamical phases, which gives ... More
Confinement with Perturbation Theory, after All?Sep 16 2014Nov 17 2014I call attention to the possibility that QCD bound states (hadrons) could be derived using rigorous Hamiltonian, perturbative methods. Solving Gauss' law for $A^0$ with a non-vanishing boundary condition at spatial infinity gives an \order{\alpha_s^0} ... More
Are hadrons simpler than they seem?Mar 07 2013I briefly review a systematic approximation scheme of QCD in which the quark model picture of hadrons emerges at lowest order. A linear A^0 potential arises if Gauss' law is solved with a non-vanishing boundary condition at spatial infinity. Similarly ... More
Measuring transverse size with virtual photonsOct 15 2011Fourier transforming the virtual photon transverse momentum in \gamma*(q)+N \to f processes allows new insight into hadron dynamics as a function of impact parameter b. I discuss how previous analyses of charge density based on elastic and transition ... More
Soft Perturbative QCDAug 30 1999There are indications of a faith transition in QCD: The strong coupling may freeze at a sufficiently low value to make PQCD relevant even in the confining regime. The properties of PQCD at low Q^2 depend on the asymptotic field configuration assumed at ... More
A simple piston problem in one dimensionMay 17 2006Aug 04 2006We study a heavy piston that separates finitely many ideal gas particles moving inside a one-dimensional gas chamber. Using averaging techniques, we prove precise rates of convergence of the actual motions of the piston to its averaged behavior. The convergence ... More
A New Class of Asymptotically Non-Chaotic Vacuum SingularitiesJul 15 2015Dec 10 2015The BKL conjecture, stated in the 60s and early 70s by Belinski, Khalatnikov and Lifshitz, proposes a detailed description of the generic asymptotic dynamics of spacetimes as they approach a spacelike singularity. It predicts complicated chaotic behaviour ... More
Timelike singularities and Hamiltonian cosmological billiardsDec 10 2015May 11 2016We construct a large class of vacuum solutions of the Einstein equations without any symmetries and with controlled asymptotics near a timelike singularity. The solutions are obtained by a Fuchs analysis of the equations which evolve the metric in a spacelike ... More
Entropy of Overcomplete Kernel DictionariesNov 01 2014In signal analysis and synthesis, linear approximation theory considers a linear decomposition of any given signal in a set of atoms, collected into a so-called dictionary. Relevant sparse representations are obtained by relaxing the orthogonality condition ... More
An eigenanalysis of data centering in machine learningJul 10 2014Many pattern recognition methods rely on statistical information from centered data, with the eigenanalysis of an empirical central moment, such as the covariance matrix in principal component analysis (PCA), as well as partial least squares regression, ... More
Approximation errors of online sparsification criteriaSep 21 2014Many machine learning frameworks, such as resource-allocating networks, kernel-based methods, Gaussian processes, and radial-basis-function networks, require a sparsification scheme in order to address the online learning paradigm. For this purpose, several ... More
Analyzing sparse dictionaries for online learning with kernelsSep 21 2014Many signal processing and machine learning methods share essentially the same linear-in-the-parameter model, with as many parameters as available samples as in kernel-based machines. Sparse approximation is essential in many disciplines, with new challenges ... More
Structure of the Standard ModelApr 19 2003The structure of the standard model is concisely summarized, including the standard model Lagrangian, spontaneous symmetry breaking, the reexpression of the Lagrangian in terms of mass eigenstates after symmetry breaking, and the gauge interactions. The ... More
Time Variation of Fundamental Constants as a Probe of New PhysicsApr 09 2003Apr 10 2003Time variation of fundamental constants would not be surprising in the framework of theories involving extra dimensions. The variation of any one constant is likely to be correlated with variations of others in a pattern that is diagnostic of the underlying ... More
Alternatives to the Seesaw: Extra Z's and Constraints on Large Extra DimensionsApr 04 2003Apr 10 2003Alternatives to the traditional grand unified theory seesaw for neutrino masses are briefly described. These include the possibility of large extra dimensions and various possibilities for models involving an extra U(1)' gauge symmetry. The difficulty ... More
Neutrino Oscillation Workshop 2000: Conference SummaryJan 22 2001The NOW2000 Workshop summarized the present status and future possibilities for all aspects of neutrino physics and astrophysics. Neutrino oscillation physics has truly come of age in the last few years. It is now data driven (analogous to cosmology and ... More
Theoretical Summary, Electroweak PhysicsMay 20 1999Aspects of theoretical electroweak physics are summarized, including the status of electroweak radiative corrections, the hadronic contribution to the running of alpha, global fits to precision data and their implication for testing the standard model ... More
Theoretical Study of the Electroweak Interaction -- Present and FutureAug 17 1994There have been several important recent developments in precision electroweak tests. These include: the new LEP energy scan during the 1993 run; the first high-precision results on the left-right asymmetry from the SLD Collaboration at SLAC; the probable ... More
Solar NeutrinosMar 10 1993The status of solar neutrino experiments and their implications for both nonstandard astrophysics ({\it e.g.,} cool sun models) and nonstandard neutrino properties ({\it e.g.,} MSW conversions) are discussed. Assuming that all of the experiments are correct, ... More
Z' Physics from StringsMay 27 1998Many extensions of the standard model, especially grand unified theories and superstring models, predict the existence of additional Z' bosons and associated exotic chiral supermultiplets. It has recently been argued that for classes of string motivated ... More
Neutrino Masses from the Top DownDec 27 2011General classes of mechanisms for generating small neutrino masses are surveyed from a top-down (superstring) perspective. In particular, string constructions have motivated various possibilities involving higher-dimensional operators, string instantons, ... More
TeV Physics from the Top DownAug 04 2003Concrete semi-realistic string/M theory constructions often predict the existence of new physics at the TeV scale, which may be different in character from the bottom-up ideas that are motivated by specific problems of the standard model. I describe two ... More
Initial Results on the F-logic to OWL Bi-directional Translation on a Tabled Prolog EngineAug 12 2008In this paper, we show our results on the bi-directional data exchange between the F-logic language supported by the Flora2 system and the OWL language. Most of the TBox and ABox axioms are translated preserving the semantics between the two representations, ... More
Flexible Audio StreamsMar 15 2007May 02 2007Tremendous research effort was invested in audio browsers and machine learning techniques to decode the structure of Web pages in order to put them into an audio format. In this paper, we address a simpler and efficient solution for the creation of an ... More
Portlet Wrappers using JavaScriptMar 14 2007May 02 2007In this paper we extend the classical portal (with static portlets) design with HTML DOM Web clipping on the client browser using dynamic JavaScript portlets: the portal server supplies the user/passwords for all services through https and the client ... More
ASTROSAT: Some Key Science ProspectsJul 22 2013ASTROSAT is an astronomy satellite designed for simultaneous multi-wavelength studies in the Optical/UV and a broad X-ray energy range. With four X-ray instruments and a pair of UV-Optical telescopes, ASTROSAT will provide unprecendented opportunity for ... More
A Complexity O(1) Priority Queue for Event Driven Molecular Dynamics SimulationsJun 26 2006We propose and implement a priority queue suitable for use in event driven molecular dynamics simulations. All operations on the queue take on average O(1) time per collision. In comparison, previously studied queues for event driven molecular dynamics ... More
Towards New Classes of Flux CompactificationsMar 27 2013We derive novel solutions of flux compactification with D7-branes on the resolved conifold in type IIB String Theory and later extend this solution to allow for non-zero temperature. At zero temperature, we find that adding D7-branes via the Ouyang embedding ... More
Signed Simplicial Decomposition and Overlay of n-D Polytope ComplexesMay 25 2012Polytope complexes are the generalisation of polygon meshes in geo-information systems (GIS) to arbitrary dimension, and a natural concept for accessing spatio-temporal information. Complexes of each dimension have a straight-forward dimension-independent ... More
A Mysterious Cluster Expansion Associated to the Expectation Value of the Permanent of 0-1 MatricesJul 04 2016Aug 19 2016We consider two ensembles of 0-1 nxn matrices. The first is the set of all nxn matrices with entries zeroes and ones such that all column sums and all row sums equal r, uniformly weighted. The second is the set of nxn matrices with zero and one entries ... More
How regular can maxitive measures be?Jan 20 2013We examine domain-valued maxitive measures defined on the Borel subsets of a topological space. Several characterizations of regularity of maxitive measures are proved, depending on the structure of the topological space. Since every regular maxitive ... More
Salem Numbers and Abelian Surface AutomorphismsJun 27 2014We classify two-dimensional complex tori admitting automorphisms with positive entropy in terms of the entropies they exhibit. For each possible positive value of entropy, we describe the set of two-dimensional complex tori admitting automorphisms with ... More
Presheaves of triangulated categories and reconstruction of schemesNov 05 2001May 28 2002To any triangulated category with tensor product $(K,\otimes)$, we associate a topological space $Spc(K,\otimes)$, by means of thick subcategories of $K$, a la Hopkins-Neeman-Thomason. Moreover, to each open subset $U$ of $Spc(K,\otimes)$, we associate ... More
Measurements of electroweak couplings of the tau lepton at L3Feb 05 1999We review the current knowledge of the couplings of the tau lepton to the electroweak gauge bosons, the W, Z and photon, obtained from the full L3 data sample at center-of-mass energies near the Z mass. Measurements of the the effective vector and axial-vector ... More
Elliptic Flow: A Study of Space-Momentum Correlations In Relativistic Nuclear CollisionsMay 02 2009Jun 04 2009Here I review measurements of v2, the second component in a Fourier decomposition of the azimuthal dependence of particle production relative to the reaction plane in heavy-ion collisions. v2 is an observable central to the interpretation of the subsequent ... More
Searching for Superhorizon Fluctuations in Heavy-Ion CollisionsAug 04 2008In this talk I discuss novel explanations for the azimuthal correlations observed in heavy-ion collisions. I review some ideas about correlations and the evolution of heavy-ion collisions. Some aspects of the correlations observed in heavy-ion collisions ... More
Identified particle measurements at RHIC: elucidating hadronization mechanisms for bulk partonic matterMay 03 2004Measurements of identified particle momentum spectra at center of mass energy 200 GeV are reviewed. Emphasis is placed on the azimuthal dependence and the centrality dependence of hadron yields at intermediate transverse momentum (1.5 < p_T < 5 GeV/c). ... More
Particle dependence of elliptic flow in Au+Au collisions at $\sqrt{s_{NN}}=$ 200 GeVMay 13 2003Oct 13 2006The elliptic flow parameter ($v_2$) for $K_S^0$ and $\Lambda+\bar{\Lambda}$ has been measured at mid-rapidity in Au + Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV by the STAR collaboration. The $v_2$ values for both $K_S^{0}$ and $\Lambda+\bar{\Lambda}$ ... More
On Operator-Valued Bi-Free DistributionsOct 13 2015In this paper, operator-valued bi-free distributions are investigated. Given a subalgebra $D$ of a unital algebra $B$, it is established that a two-faced family $Z$ is bi-free from $(B, B^{\mathrm{op}})$ over $D$ if and only if certain conditions relating ... More
A Framework for Partial SecrecyAug 03 2010Aug 04 2010We consider theoretical limits of partial secrecy in a setting where an eavesdropper attempts to causally reconstruct an information sequence with low distortion based on an intercepted transmission and the past of the sequence. The transmitter and receiver ... More
The dimension of affine Deligne-Lusztig varieties in the affine Grassmannian of unramified groupsDec 02 2013Mar 09 2015In this paper we calculate the dimension of affine Deligne-Lusztig varieties in the affine Grassmannian of unramified groups. We also examine the irreducible components of ADLVs in the superbasic case and the $J_b(F)$-action on them.
Domain theory and mirror properties in inverse semigroupsJan 24 2013Inverse semigroups are a class of semigroups whose structure induces a compatible partial order. This partial order is examined so as to establish mirror properties between an inverse semigroup and the semilattice of its idempotent elements, such as continuity ... More
Recent progress on univariate and multivariate polynomial and spline quasi-interpolantsMay 03 2004Polynomial and spline quasi-interpolants (QIs) are practical and effective approximation operators. Among their remarkable properties, let us cite for example: good shape properties, easy computation and evaluation (no linear system to solve), uniform ... More
Zeta Functions, the Tate Conjecture, and Catanese SurfacesNov 15 2011Nov 16 2011This paper has been withdrawn by the author due to an error in the sufficient condition given for the proof of the Tate conjecture for Catanese surfaces.