Results for "Paul Hickson"

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Eliminating the Coriols Effect in Liquid MirrorsAug 18 2001If uncorrected, the Coriolis force due to the rotation of the Earth causes significant aberration of images produced by large liquid-mirror telescopes. We show that this problem can be eliminated by a fixed compensating tilt of the liquid-mirror rotation ... More
A Technique for Photometric Detection and Measurement of Unresolved Binary SystemsNov 29 1997A technique is described for the detection and measurement of close binary systems whose images are unresolved. The method is based on analysis of the moment of inertia tensor of the image, from which the product of the binary flux ratio and square of ... More
Wide-field tracking with zenth-pointing telescopesJun 12 2001Equipped with a suitable optical relay system, telescopes employing low-cost fixed primary mirrors could point and track while delivering high-quality images to a fixed location. Such an optical tracking system would enable liquid-mirror telescopes to ... More
Topology of the Las Campanas Redshift SurveyJul 10 2000Jul 12 2000The topology of the Las Campanas Redshift Survey is analyzed using Minkowski functional statistics, taking into account the selection effects of the survey. The results are compared with the predictions of some toy models of structure formation, including ... More
Compact groups of galaxiesOct 25 1997Compact groups of galaxies have posed a number of challenging questions. Intensive observational and theoretical studies are now providing answers to many of these, and at the same time, are revealing unexpected new clues about the nature and role of ... More
A Curvature-Compensated Corrector for Drift-Scan ObservationsJun 23 1998Images obtained by drift-scanning with a stationary telescope are affected by the declination-dependent curvature of star trails. The image displacement to curvature and drift rate variation increases with the angular field of view and can lead to significant ... More
Remote sensing of geomagnetic fields and atomic collisions in the mesosphereFeb 09 2018Magnetic-field sensing has contributed to the formulation of the plate-tectonics theory, the discovery and mapping of underground structures on Earth, and the study of magnetism in other planets. Filling the gap between space-based and near-Earth observation, ... More
UBC-NASA Multi-Narrowband Survey. I. Description and Photometric Properties of the SurveyOct 03 1997Observations, analysis techniques and photometric properties of a multi-narrowband survey of a 20 square-degree area of sky at +33 degrees declination are described. The survey is conducted with the 3-meter liquid-mirror telescope of the NASA Orbital ... More
Using Site Testing Data for Adaptive Optics SimulationsJan 12 2011Astronomical Site testing data plays a vital role in the simulation, design, evaluation and operation of adaptive optics systems for large telescope. We present the example of TMT and its first light facilitiy adaptive optics system NFIRAOS, and illustrate ... More
The Large Zenith Telescope Survey: a deep survey using a 6-m liquid mirror telescopeDec 18 2001The Large Zenith Telescope Survey whose construction is almost completed (first light expected in spring 2002) near Vancouver (Canada) is designed to observed a total strip of ~17' x 120 deg in 40 medium-band filters spanning 4000-10000 A. It will gather ... More
The 2-point angular correlation function of 20,000 galaxies to V<23.5 and I<22Jul 13 2000The UH8K wide field camera of the CFHT was used to image 0.68 deg^2 of sky. From these images, ~20,000 galaxies were detected to completeness magnitudes V<23.5 and I<22.5. The angular correlation function of these galaxies is well represented by the parameterization ... More
Classification and redshift estimation by principal component analysisJun 04 2002Jun 07 2002We show that the first 10 eigencomponents of the Karhunen-Lo\`eve expansion or Principal Component Analysis (PCA) provide a robust classification scheme for the identification of stars, galaxies and quasi-stellar objects from multi-band photometry. To ... More
The fast C(3P) + CH3OH reaction as an efficient loss process for gas-phase interstellar methanolJun 05 2014Rate constants for the C(3P) + CH3OH reaction have been measured in a continuous supersonic flow reactor over the range 50 K to 296 K. C(3P) was created by the in-situ pulsed laser photolysis of CBr4, a multiphoton process which also produced some C(1D), ... More
Discordant Redshifts in Compact GroupsOct 17 1996This paper addresses the long standing question of discordant redshifts in compact groups. We have used an homogenous catalogue of 173 compact groups selected by an automated procedure to objectively predict the fraction of discordant redshifts with high ... More
The zenithal 4-m International Liquid Mirror Telescope: a unique facility for supernova studiesFeb 01 2018The 4-m International Liquid Mirror Telescope (ILMT) will soon become operational at the newly developed Devasthal observatory near Nainital (Uttarakhand, India). Coupled with a 4k $\times$ 4k pixels CCD detector and TDI optical corrector, it will reach ... More
A cryogenic liquid-mirror telescope on the moon to study the early universeJun 13 2008We have studied the feasibility and scientific potential of zenith observing liquid mirror telescopes having 20 to 100 m diameters located on the moon. They would carry out deep infrared surveys to study the distant universe and follow up discoveries ... More
Unusual Low Temperature Reactivity of Water. The CH + H2O Reaction as a Source of Interstellar Formaldehyde?Aug 19 2013Water is an important reservoir species for oxygen in interstellar space and plays a key role in the physics of star formation through cooling by far-infrared emission. Whilst water vapour is present at high abundances in the outflows of protostars, its ... More
Similarity-based Browsing over Linked Open DataJun 21 2011An increasing amount of data is published on the Web according to the Linked Open Data (LOD) principles. End users would like to browse these data in a flexible manner. In this paper we focus on similarity-based browsing and we introduce a novel method ... More
Topological Statistics and the LMT Galaxy Redshift SurveyJun 26 1998The results of numerical simulations are presented which demonstrate that liquid mirror telescope galaxy redshift surveys such as the current UBC-NASA Multi-Narrowband Survey and the future LZT Survey have the potential of discriminating between the predictions ... More
An experimental and theoretical investigation of the C(1D) + D2 reactionNov 06 2016In a previous joint experimental and theoretical study of the barrierless chemical reaction C(1D) + H2 at low temperatures (300-50 K) [K. M. Hickson, J.-C. Loison, H. Guo, Y. V. Suleimanov, J. Phys. Chem. Lett., 2015, 6, 4194.], excellent agreement was ... 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
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
Temporal variability of the telluric sodium layerSep 12 2006The temporal variability of the telluric sodium layer is investigated by analyzing 28 nights of data obtained with the Colorado State University LIDAR experiment. The mean height power spectrum of the sodium layer was found to be well fit by a power law ... More
A proposed chemical scheme for HCCO formation in cold dense cloudsSep 01 2015The ketenyl radical (HCCO) has recently been discovered in two cold dense clouds with a non-negligible abundance of a few 1e-11 (compared to H2) (Agundez et al. 2015). Until now, no chemical network has been able to reproduce this observation. We propose ... More
Methylacetylene (CH3CCH) and propene (C3H6) formation in cold dense clouds: a case of dust grain chemistryMar 08 2016We present an extensive review of gas phase reactions producing methylacetylene and propene showing that these relatively abundant unsaturated hydrocarbons cannot be synthesized through gas-phase reactions. We explain the formation of propene and methylacetylene ... More
Isotopic fractionation of carbon, deuterium and nitrogen : a full chemical studyJan 06 2015Jan 08 2015Context. The increased sensitivity and high spectral resolution of millimeter telescopes allow the detection of an increasing number of isotopically substituted molecules in the interstellar medium. The 14N/ 15N ratio is difficult to measure directly ... More
Temperature Dependent Product Yields for the Spin Forbidden Singlet Channel of the C(3P) + C2H2 ReactionJul 05 2016The atomic hydrogen formation channels of the C + C2H2 reaction have been investigated using a continuous supersonic flow reactor over the 52 K 296 K temperature range. H-atoms were detected directly at 121.567 nm by vacuum ultraviolet laser induced fluorescence. ... More
The interstellar gas-phase chemistry of HCN and HNCJun 06 2014We review the reactions involving HCN and HNC in dark molecular clouds to elucidate new chemical sources and sinks of these isomers. We find that the most important reactions for the HCN-HNC system are Dissociative Recombination (DR) reactions of HCNH+ ... More
The different Clustering of red and blue galaxies: a robust signal from w(theta)Dec 18 2001A sample of ~20,000 galaxies covering 0.76 deg2 were observed with the CFHT-UH8K up to V<23.5 and I<22.5. The angular correlation analysis of the red selected sample (V-I>1.4) shows a stronger amplitude than the blue selected sample at all cutoff magnitudes. ... More
Astronomical seeing and ground-layer turbulence in the Canadian High ArcticMay 03 2013We report results of a two-year campaign of measurements, during arctic winter darkness, of optical turbulence in the atmospheric boundary-layer above the Polar Environment Atmospheric Laboratory in northern Ellesmere Island (latitude +80 deg N). The ... More
Summary Talk on Quark-Hadron DualitySep 14 2005I ascribe the origin of Bloom-Gilman duality in DIS to a separation of scales between the hard subprocess and soft resonance formation. The success of duality indicates that the subprocesses of exclusive form factors are the same as in DIS. The observed ... More
The Dynamics of Quarkonium ProductionSep 13 1998Quarkonium production is a sensitive probe of the dynamics of hard scattering, which can `measure' the environment of the heavy quark pair after it is created in a hard process. Quarkonium hadroproduction data indicates that the produced pair experiences ... More
Hadron StructureOct 26 2010I discuss a Born (\hbar \to 0) approximation of hadrons, motivated by a general feature of the data: The spectra of hadrons reflect their valence (q\bar q or qqq) constituents, whereas hard scattering reveals a prominent sea quark distribution. Why do ... More
Rescattering Effects on DIS Parton DistributionsAug 02 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
A Perturbative Gluon Condensate?Oct 07 1996I propose that the properties of QCD perturbation theory should be investigated when the boundary state (`perturbative vacuum') at $t= \pm\infty$ includes gluons. Any boundary state that has an overlap with the true QCD ground state generates a perturbative ... More
The Schwinger Model and Perturbative Charge ScreeningMar 16 1993Jul 13 1993\noindent The well-known exact solution of the massless Schwinger model can be simply obtained by perturbing around a vacuum without the Dirac sea of filled negative energy states. The unusual vacuum structure changes the sign of the $i\epsilon$ prescription ... More
Rigorous Results for the Periodic Oscillation of an Adiabatic PistonApr 05 2007We study a heavy piston of mass $M$ that moves in one dimension. The piston separates two gas chambers, each of which contains finitely many ideal, unit mass gas particles moving in $d$ dimensions, where $ d\geq 1$. Using averaging techniques, we prove ... More
Connections of Zero Curvature and Applications to Nonlinear Partial Differential EquationsFeb 28 2014A general formulation of zero curvature connections in a principle bundle is presented and some applications are discussed. It is proved that a related connection based on a prolongation in an associated bundle remains zero curvature as well. It is also ... More
Interpolation without continuity in partially ordered setsJan 06 2013Sep 26 2014We are interested in posets with the interpolation property that are not necessarily continuous. We show that every conditionally-complete poset $P$ with the interpolation property contains a largest continuous poset whose way-below relation is the restriction ... More
Leonard pairs and the q-Racah polynomialsJun 19 2003Jul 24 2008Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider an ordered pair of linear transformations $A:V\to V$ and $A^*:V\to V$ that satisfy conditions (i), (ii) below. (i) There exists a basis for $V$ ... More
A monomorphism theorem for the inverse limit of nested retractsFeb 13 2005Apr 22 2005Various characterizations are offered of injectivity of the canonical fundamental group homomorphism for a certain class of inverse limit spaces. One application characterizes the existence of a kind of generalized universal cover.
The canonical fractional Galois ideal at s=0Mar 18 2008The Stickelberger elements attached to an abelian extension of number fields conjecturally participate, under certain conditions, in annihilator relations involving higher algebraic K-groups. In [Victor P. Snaith, Stark's conjecture and new Stickelberger ... More
Simple Optimal Wait-free Multireader RegistersFeb 04 2002Dec 15 2005Multireader shared registers are basic objects used as communication medium in asynchronous concurrent computation. We propose a surprisingly simple and natural scheme to obtain several wait-free constructions of bounded 1-writer multireader registers ... More
Tolstoy's Mathematics in "War and Peace"Oct 18 2001The nineteenth century Russian author Leo Tolstoy based his egalitarian views on sociology and history on mathematical and probabilistic views, and he also proposed a mathematical theory of waging war.
Three Approaches to the Quantitative Definition of Information in an Individual Pure Quantum StateJul 09 1999May 04 2000In analogy of classical Kolmogorov complexity we develop a theory of the algorithmic information in bits contained in any one of continuously many pure quantum states: quantum Kolmogorov complexity. Classical Kolmogorov complexity coincides with the new ... More
Algorithmic ChaosMar 07 2003Many physical theories like chaos theory are fundamentally concerned with the conceptual tension between determinism and randomness. Kolmogorov complexity can express randomness in determinism and gives an approach to formulate chaotic behavior.
Meaningful InformationNov 20 2001Dec 09 2006The information in an individual finite object (like a binary string) is commonly measured by its Kolmogorov complexity. One can divide that information into two parts: the information accounting for the useful regularity present in the object and the ... More
Finiteness for Mapping Class Group Representations from Twisted Dijkgraaf-Witten TheoryOct 19 2016Any twisted Dijkgraaf-Witten representation of a mapping class group of an orientable, compact surface with boundary has finite image.
The reciprocals of some characteristic 2 "theta series"Jul 20 2011Suppose l=2m+1, m>0. We introduce m "theta-series", [1],...,[m], in Z/2[[x]]. It has been conjectured that the n for which the coefficient of x^n in 1/[i] is 1 form a set of density 0. This is probably always false, but in certain cases, for n restricted ... More
Frobenius' result on simple groups of order (p^3-p)/2Jul 20 2011The complete list of pairs of non-isomorphic finite simple groups having the same order is well-known. In particular for p>3, PSL_2(Z/p) is the "only" simple group of order (p^3-p)/2. It's less well-known that Frobenius proved this uniqueness result in ... More
Disquisitiones Arithmeticae and online sequence A108345Sep 21 2010Let g be the element that is the sum of x^(n^2) for n >= 0 of A=Z/2[[x]], and let B consist of all n for which the coefficient of x^n in 1/g is 1. (The elements of B are the entries 0, 1, 2, 3, 5, 7, 8, 9, 13, ... in A108345; see The On-Line Encyclopedia ... More
Tight closure's failure to localize - a self-contained expositionFeb 06 2009We give a treatment of the Brenner-Monsky example based on polynomial algebra and linear algebra. No prior knowledge of tight closure theory, Hilbert-Kunz theory, algebraic geometry or local cohomology is assumed.
Algebraicity of some Hilbert-Kunz multiplicities (modulo a conjecture)Jul 15 2009Let F be a finite field of characteristic 2 and h be the element x^3+y^3+xyz of F[[x,y,z]]. In an earlier paper we made a precise conjecture as to the values of the colengths of the ideals (x^q,y^q,z^q,h^j) for q a power of 2. We also showed that if the ... More
The BinProlog Experience: Architecture and Implementation Choices for Continuation Passing Prolog and First-Class Logic EnginesFeb 06 2011We describe the BinProlog system's compilation technology, runtime system and its extensions supporting first-class Logic Engines while providing a short history of its development, details of some of its newer re-implementations as well as an overview ... More
Ranking and Unranking of Hereditarily Finite Functions and PermutationsAug 05 2008Prolog's ability to return multiple answers on backtracking provides an elegant mechanism to derive reversible encodings of combinatorial objects as Natural Numbers i.e. {\em ranking} and {\em unranking} functions. Starting from a generalization of Ackerman's ... More
A Logic Programming Playground for Lambda Terms, Combinators, Types and Tree-based Arithmetic ComputationsJul 24 2015With sound unification, Definite Clause Grammars and compact expression of combinatorial generation algorithms, logic programming is shown to conveniently host a declarative playground where interesting properties and behaviors emerge from the interaction ... More
Binary Tree Arithmetic with Generalized ConstructorsJan 01 2013We describe arithmetic computations in terms of operations on some well known free algebras (S1S, S2S and ordered rooted binary trees) while emphasizing the common structure present in all them when seen as isomorphic with the set of natural numbers. ... More
Declarative Combinatorics: Isomorphisms, Hylomorphisms and Hereditarily Finite Data Types in HaskellAug 21 2008Jan 19 2009This paper is an exploration in a functional programming framework of {\em isomorphisms} between elementary data types (natural numbers, sets, multisets, finite functions, permutations binary decision diagrams, graphs, hypergraphs, parenthesis languages, ... More
Dust and Ionized gas in Elliptical GalaxiesNov 08 1996Results from IRAS and recent X-ray and optical surveys are reviewed to discuss the properties and nature of the interstellar medium in elliptical galaxies. As to the dust component, there is a strong contrast with the situation among spiral galaxies in ... More
Sizes, Half-Mass Densities, and Mass Functions of Star Clusters in the Merger Remnant NGC 1316: Clues to the Fate of Second-Generation Globular ClustersMar 06 2012Apr 26 2012We study mass functions of globular clusters derived from HST/ACS images of the early-type merger remnant galaxy NGC 1316 which hosts a significant population of metal-rich globular clusters of intermediate age (~3 Gyr). For the old, metal-poor (`blue') ... More
Cyclic Spectral Analysis of Radio PulsarsJun 16 2011Cyclic spectral analysis is a signal processing technique designed to deal with stochastic signals whose statistics vary periodically with time. Pulsar radio emission is a textbook example of this signal class, known as cyclostationary signals. In this ... More
The Universal Askey-Wilson AlgebraApr 14 2011Jul 15 2011In 1992 A. Zhedanov introduced the Askey-Wilson algebra AW=AW(3) and used it to describe the Askey-Wilson polynomials. In this paper we introduce a central extension $\Delta$ of AW, obtained from AW by reinterpreting certain parameters as central elements ... More
Some Properties of Transforms in Culture TheoryMar 07 2009It is shown that, in certain circumstances, systems of cultural rules may be represented by doubly stochastic matrices denoted called possibility transforms, and by certain real valued possibility densities with inner product. Using such objects we may ... More
Hausdorff Dimension of Average Conformal Hyperbolic SetsJan 06 2014Jan 18 2014The Hausdorff dimension of a conformal repeller or conformal hyperbolic set is well understood. For non-conformal maps, the Hausdorff dimension is only known in some special cases. Ban, Cao and Hu defined the concept of an average conformal repeller which ... More
State Information in Bayesian GamesNov 04 2009Two-player zero-sum repeated games are well understood. Computing the value of such a game is straightforward. Additionally, if the payoffs are dependent on a random state of the game known to one, both, or neither of the players, the resulting value ... More
Coisotropic D-branes on AdS4 x CP3 and massive deformationsApr 01 2009Jun 05 2009We scan for massive type IIA SU(3)-structure compactifications of the type AdS4 x CP3 with internal symmetry group SO(4). This group acts on CP3 with cohomogeneity one, so that one would expect new non-homogeneous solutions. We find however that all such ... More
Lectures on Generalized Complex Geometry for PhysicistsJun 08 2010Sep 02 2010In these lectures we review Generalized Complex Geometry and discuss two main applications to string theory: the description of supersymmetric flux compactifications and the supersymmetric embedding of D-branes. We start by reviewing G-structures, and ... More
A Deep Multicolor Survey. VI. Near-Infrared Observations, Selection Effects, and Number CountsAug 21 2000Oct 18 2000I present near-infrared J (1.25um), H (1.65um), and K (2.2um) imaging observations of 185 square arcminutes in 21 high galactic latitude fields. These observations reach limiting magnitudes of J ~ 21 mag, H ~ 20 mag and K ~ 18.5 mag. The detection efficiency, ... More
Nonstandard Hausdorff dimension in $\mathbb{R}^n$ and an application to the Kakeya conjecture in $\mathbb{R}^3$Aug 27 2013Aug 28 2013Through the use of a nonstandard version of Frostman's lemma, the notion of Hausdorff dimension is formulated in nonstandard euclidean space of arbitrary dimension. This allows for a nonstandard proof of the Kakeya conjecture in two dimensions, which ... More
Reference Frame Fields based on Quantum Theory Representations of Real and Complex NumbersSep 17 2007Mar 05 2008A quantum theory representations of real (R) and complex (C) numbers is given that is based on states of single, finite strings of qukits for any base k > 1. Both unary representations and the possibility that qukits with k a prime number are elementary ... More
Fields of quantum reference frames based on different representations of rational numbers as states of qubit stringsNov 13 2006In this paper fields of quantum reference frames based on gauge transformations of rational string states are described in a way that, hopefully, makes them more understandable than their description in an earlier paper. The approach taken here is based ... More
A simple Example of Definitions of Truth, Validity, Consistency, and Completeness in Quantum MechanicsNov 20 1998Dec 18 1998Besides their use for efficient computation, quantum computers are a base for studying quantum systems that create valid physical theories using mathematics and physics. An essential part of the validation process for quantum mechanics is the development ... More
Quantum Robots and Quantum ComputersJun 04 1997Dec 18 1997Validation of a presumably universal theory, such as quantum mechanics, requires a quantum mechanical description of systems that carry out theoretical calculations and experiments. The description of quantum computers is under active development. No ... More
Transmission and Spectral Aspects of Tight Binding Hamiltonians for the Counting Quantum Turing MachineJan 02 1997It was recently shown that a generalization of quantum Turing machines (QTMs), in which potentials are associated with elementary steps or transitions of the computation, generates potential distributions along computation paths of states in some basis ... More
Space and time dependent scaling of numbers in mathematical structures: Effects on physical and geometric quantitiesAug 07 2015The relationship between the foundations of mathematics and physics is a topic of of much interest. This paper continues this exploration by examination of the effect of space and time dependent number scaling on theoretical descriptions of some physical ... More
A Possible Approach to Inclusion of Space and Time in Frame Fields of Quantum Representations of Real and Complex NumbersSep 25 2008Aug 26 2009This work is based on the field of reference frames based on quantum representations of real and complex numbers described in other work. Here frame domains are expanded to include space and time lattices. Strings of qukits are described as hybrid systems ... More
The Landauer Resistance and Band Spectra for the Counting Quantum Turing MachineFeb 07 1997The generalized counting quantum Turing machine (GCQTM) is a machine which, for any N, enumerates the first $2^{N}$ integers in succession as binary strings. The generalization consists of associating a potential with read-1 steps only. The Landauer Resistance ... More
Tight Binding Hamiltonians and Quantum Turing MachinesOct 17 1996This paper extends work done to date on quantum computation by associating potentials with different types of computation steps. Quantum Turing machine Hamiltonians, generalized to include potentials, correspond to sums over tight binding Hamiltonians ... More
Generalized Wess-Zumino Consistency Conditions for Pure W_3 Gravity AnomaliesSep 08 1995General expressions for the anomalies appearing in pure W_3 gravity are found by requiring that they satisfy a modified version of the Wess-Zumino consistency conditions in which the Ward identities are treated as nonvanishing quantities.
Monopoles in AdSApr 11 2011Sep 01 2011Applications to holographic theories have led to some recent interest in magnetic monopoles in four-dimensional Anti-de Sitter spacetime. This paper is concerned with a study of these monopoles, using both analytic and numerical methods. An approximation ... More
Isotropic cosmological singularities in spatially-homogeneous models with a cosmological constantApr 19 2007We prove well-posedness of the initial value problem for the Einstein equations for spatially-homogeneous cosmologies with data at an isotropic cosmological singularity, for which the matter content is either a cosmological constant with collisionless ... More
Diffractive Phenomena at HERAJan 18 1999Highlights selected from recent measurements of colour-singlet exchange processes at HERA are summarised. Particular emphasis is placed on energy and momentum transfer dependences and the decomposition of the data into an expansion in Regge trajectories. ... More
Random-time isotropic fractional stable fieldsDec 20 2011Jun 27 2012Generalizing both Substable FSMs and Indicator FSMs, we introduce alpha-stabilized subordination, a procedure which produces new FSMs (H-sssi symmetric stable processes) from old ones. We extend these processes to isotropic stable fields which have stationary ... More
Extremal Reversible Measures for the Exclusion ProcessSep 14 2003We give a characterization of the invariant measures for the exclusion process on the integers with certain reversible transition kernels. Some examples include all nearest-neighbor kernels with asymptotic mean zero. One tool used is a necessary and sufficient ... More
Construction of uniformly bounded periodic continued fractionsJan 29 2016We build, for real quadratic fields, infinitely many periodic continuous fractions uniformly bounded, with a seemingly better bound than the known ones. We do that using continuous fraction expansions with the same shape as those of real numbers sqrt(n) ... More
Billiard Arrays and finite-dimensional irreducible $U_q(\mathfrak{sl}_2)$-modulesAug 01 2014We introduce the notion of a Billiard Array. This is an equilateral triangular array of one-dimensional subspaces of a vector space $V$, subject to several conditions that specify which sums are direct. We show that the Billiard Arrays on $V$ are in bijection ... More
Measurement of the inclusive electron cross-section from the decays of heavy flavour hadrons in pp collisions at sqrt(s) = 7 TeV at ATLASNov 22 2011We present the measurement of the inclusive electron spectrum in proton-proton collisions at a centre-of-mass energy of 7 TeV, using 1.3 pb-1 of data collected by the ATLAS experiment at the Large Hadron Collider. Signal electrons in the transverse momentum ... More
Neutrino Physics (theory)Nov 08 2004Nonzero neutrino masses are the first definitive need to extend the standard model. After reviewing the basic framework, I describe the status of some of the major issues, including tests of the basic framework of neutrino masses and mixings; the question ... More
Beyond the MSSMFeb 19 2004Specific quasi-realistic superstring constructions often predict the existence of new TeV-scale physics which may be different in character from bottom-up motivated constructions. I describe examples of such beyond the MSSM physics, with special emphasis ... More
Grand Unification and the Standard ModelNov 08 1994The current status of gauge unification is surveyed both in the standard model and its minimal supersymmetric extension. Implications for proton decay, Yukawa unification, and the Higgs mass are described.
Introduction to the Standard Model and Electroweak PhysicsJan 02 2009A concise introduction is given to the standard model, including the structure of the QCD and electroweak Lagrangians, spontaneous symmetry breaking, experimental tests, and problems.
Precision Tests of the Standard ModelMar 24 1993The implications of recent precision $Z$-pole, $W$ mass, and weak neutral current data for testing the standard electroweak model, constraining the $t$ quark and Higgs masses, \alsz, and grand unification are discussed. A fit to all data yields $\siz ... More
A GPU implementation of the Simulated Annealing Heuristic for the Quadratic Assignment ProblemAug 13 2012The quadratic assignment problem (QAP) is one of the most difficult combinatorial optimization problems. An effective heuristic for obtaining approximate solutions to the QAP is simulated annealing (SA). Here we describe an SA implementation for the QAP ... More
Comparative Performance of Tabu Search and Simulated Annealing Heuristics for the Quadratic Assignment ProblemOct 01 2010For almost two decades the question of whether tabu search (TS) or simulated annealing (SA) performs better for the quadratic assignment problem has been unresolved. To answer this question satisfactorily, we compare performance at various values of targeted ... More
A Variable Depth Sequential Search Heuristic for the Quadratic Assignment ProblemDec 30 2009We develop a variable depth search heuristic for the quadratic assignment problem. The heuristic is based on sequential changes in assignments analogous to the Lin-Kernighan sequential edge moves for the traveling salesman problem. We treat unstructured ... More
An orthogonal polynomial coefficient formula for the Hankel transformMar 30 2011We give an explicit formula for the Hankel transform of a regular sequence in terms of the coefficients of the associated orthogonal polynomials and the sequence itself. We apply this formula to some sequences of combinatorial interest, deriving interesting ... More
The Illusion of Requirements in Software DevelopmentMar 30 2013It is widely accepted that understanding system requirements is important for software development project success. However, this paper presents two novel challenges to the requirements concept. First, where many plausible approaches to achieving a goal ... More
A Conversation With Harry MartzAug 02 2007Harry F. Martz was born June 16, 1942 and grew up in Cumberland, Maryland. He received a Bachelor of Science degree in mathematics (with a minor in physics) from Frostburg State University in 1964, and earned a Ph.D. in statistics at Virginia Polytechnic ... More
The spectrum of prime ideals in tensor triangulated categoriesSep 20 2004Sep 22 2004We define the spectrum of a tensor triangulated category $K$ as the set of so-called prime ideals, endowed with a suitable topology. In this very generality, the spectrum is the universal space in which one can define supports for objects of $K$. This ... More
An Illustrated Introduction to the Truncated Fourier TransformFeb 15 2016Feb 17 2016The Truncated Fourier Transform (TFT) is a variation of the Discrete Fourier Transform (DFT/FFT) that allows for input vectors that do NOT have length $2^n$ for $n$ a positive integer. We present the univariate version of the TFT, originally due to Joris ... More