Results for "Collins Amburo Agyingi"
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$n$-tuple fixed point in $φ$-ordered $G$-metric spacesSep 22 2017We use three seminal approaches in the study of fixed point theory, the so called $G$-metrics, multidimensional fixed points and partially ordered spaces. More precisely, we extend known results from the theory of quasi-pseudometric spaces to the $G$-metric ... More ($2k+1)^{th}$-order Fixed points in $G$-metric spacesSep 22 2017We establish three major fixed-point theorems for functions satisfying an odd power type contractive condition in G-metric spaces. We first consider the case of a single mapping, followed by that of a triplet of mappings and we conclude by the case of ... More Weak contractions via $λ$-sequencesMar 30 2018In this note, we discuss common fixed point for a family of self mapping defined on a metric type space and satisfying a weakly contractive condition. In our development, we make use of the $\lambda$-sequence approach and also of a certain class of real ... More Startpoints via weak contractionsMar 30 2018Startpoints (resp. endpoints) can be defined as "oriented fixed points". They arise naturally in the study of fixed for multi-valued maps defined on quasi-metric spaces. In this article, we give a new result in the startpoint theory for quasi-pseudometric ... More Chatterjea type fixed point in Partial $b$-metric spacesFeb 08 2019In this paper, we give and prove two Chatterjea type fixed point theorems on partial $b$-metric space. We propose an extension to the Banach contraction principle on partial $b$-metric space which was already presented by Shukla and also study some related ... More Interactional Expertise and EmbodimentJul 27 2016In Part 1 of this paper, I introduce the idea of interactional expertise while in Part 2, I focus on its implications for philosophical theories of the importance of the body in forming our conceptual world. I argue that the way philosophers have dealt ... More Mixed state Pauli channel parameter estimationAug 29 2012The accuracy of any physical scheme used to estimate the parameter describing the strength of a single qubit Pauli channel can be quantified using standard techniques from quantum estimation theory. It is known that the optimal estimation scheme, with ... More The Mass of the b Quark from Lattice NRQCDSep 29 2000Oct 09 2000We present results for the mass of the $b$ quark in the $\bar{MS}$ scheme obtained by calculating the binding energy of the $B$ meson in the static limit. The self energy of a static quark, $E_0^\infty$ needed for this purpose, is now known to $O(\alpha^3)$ ... More Trans-Planckian relics in the scalar to tensor ratioOct 31 2008The physical properties of our universe at energy scales above the expansion rate during inflation can affect predictions for the ratio between the amplitudes of the primordial scalar and tensor fluctuations. In particular, we study here the effects of ... More Dynamics forced by surface trellisesJul 13 1999Given a saddle fixed point of a surface diffeomorphism, its stable and unstable curves $W^S$ and $W^U$ often form a homoclinic tangle. Given such a tangle, we use topological methods to find periodic points of the diffeomorphism, using only a subset of ... More On the concordance orders of knotsJun 04 2012This thesis develops some general calculational techniques for finding the orders of knots in the topological concordance group C. The techniques currently available in the literature are either too theoretical, applying to only a small number of knots, ... More Construction of a Prototype Spark ChamberOct 19 2010A small demonstration spark chamber is to be built at the Cavendish laboratory. A prototype chamber consisting of five 20x22.5cm plates has been built and descriptions of its properties and construction are given, while a second chamber with a somewhat ... More 2-soft-gluon exchange and factorization breakingAug 31 2007A previous counterexample to disprove k_T-factorization for H_1+H_2 --> H_3+H_4+X is extended calculationally to one higher order in gluon exchange. The result is that, by explicit calculation, standard k_T-factorization fails for the unpolarized cross-section ... More Three Generative, Lexicalised Models for Statistical ParsingJun 17 1997In this paper we first propose a new statistical parsing model, which is a generative model of lexicalised context-free grammar. We then extend the model to include a probabilistic treatment of both subcategorisation and wh-movement. Results on Wall Street ... More Restricted Schur Polynomials and Finite N CountingOct 23 2008Restricted Schur polynomials have been posited as orthonormal operators for the change of basis from N=4 SYM to type IIB string theory [1,2,3,4]. In this letter we briefly expound the relationship found between the restricted Schurs and the operators ... More Embedded Spreadsheet ModellingAug 08 2009In larger accounting firms, specialist modellers typically sit in separate teams. This paper will look at the advantages of embedding a specialist modeller within a Corporate Finance Team. Quasars and Galactic Nuclei,a Half-Century Agitated StoryApr 27 2006Sep 01 2006I recall how the discovery of quasars occurred more than forty years ago, and the strong debates marking out their story. It led to the discovery of Massive Black Holes, which are now known to be present in almost all galaxies, and it opened on a coherent ... More A new approach to the LSZ reduction formulaApr 24 2019Lehmann, Symanzik and Zimmermann (LSZ) proved a theorem showing how to obtain the S-matrix from time-ordered Green functions. Their result, the reduction formula, is fundamental to practical calculations of scattering processes. A known problem is that ... More An Imitation Game concerning gravitational wave physicsJul 25 2016The 'Imitation Game' is a Turing Test played with a human participant instead of a computer. Here the author, a sociologist, who has been immersed in the field of gravitational wave physics since 1972, tried to pass an Imitation Game as a gravitational ... More Martin Boundary Theory of some Quantum Random WalksNov 22 2002In this paper we define a general setting for Martin boundary theory associated to quantum random walks, and prove a general representation theorem. We show that in the dual of a simply connected Lie subgroup of U(n), the extremal Martin boundary is homeomorphic ... More The L^2 signature of torus knotsJan 08 2010Jun 25 2010We find a formula for the L2 signature of a (p,q) torus knot, which is the integral of the omega-signatures over the unit circle. We then apply this to a theorem of Cochran-Orr-Teichner to prove that the n-twisted doubles of the unknot, for n not 0 or ... More Rapidity divergences and valid definitions of parton densitiesAug 19 2008Sep 04 2008Rapidity divergences occur when parton densities in a gauge theory are defined in the most natural way, as expectation values of partonic number operators in light-front quantization. I review these and other related divergences, and show how the definitions ... More Monte-Carlo Event Generators at NLOOct 08 2001A method to construct Monte-Carlo event generators at arbitrarily non-leading order is explained for the case of a non-gauge theory. A precise and correct treatment of parton kinematics is provided. Modifications of the conventional formalism are required: ... More The Problem Of Scales: Renormalization and All ThatOct 11 1995Feb 12 2009I explain the methods that are used in field theory for problems involving typical momenta on two or more widely disparate scales. The principal topics are: (a) renormalization, which treats the problem of taking an ultra-violet cut-off to infinity, (b) ... More Polarized Beam JetsOct 10 1995Handedness and a left-right asymmetry have been proposed as methods of probing the polarization of hard jets. If the analyzing powers for these observables are substantial they would provide useful tools for probing polarized hard scattering. This paper ... More A Minimal Non-solvable Group of HomeomorphismsAug 07 2006Let $PL_0(I)$ represent the group of orientation-preserving piecewise-linear homeomorphisms of the unit interval which admit finitely many breaks in slope, under the operation of composition. We find a non-solvable group $W$ and show that $W$ embeds in ... More Non LTE radiation processes: application to the solar coronaJan 12 2001These lectures are intended to present a simple but relatively complete description of the theory needed to understand the formation of lines in non-local thermodynamical equilibrium (NLTE), without appealing to any previous knowledge except a few basics ... More New definition of TMD parton densitiesJul 20 2011I give an account of a new definition of transverse-momentum-dependent parton densities. The new definition solves a number of difficulties and inconsistencies in earlier definitions. QCD and DiffractionJun 12 2001I review some of the main results on hard diffraction, in their relation to QCD, and indicate some of the strengths and weaknesses of the arguments. I also make some suggestions for future work. Light-cone Variables, Rapidity and All ThatMay 22 1997I give a pedagogical summary of the methods of light-cone variables, rapidity and pseudo-rapidity. Then I show how these methods are useful in analyzing diffractive high-energy collisions. TMD theory, factorization and evolutionJul 10 2013The concepts and methods of factorization using transverse-momentum-dependent (TMD) parton densities and/or fragmentation functions are summarized. CSS Equation, etc, Follow from Structure of TMD FactorizationDec 24 2012I show that the forms of the Collins-Soper-Sterman and renormalization-group equations for the evolution of transverse-momentum-dependent (TMD) parton densities in QCD follow from the structure of TMD factorization. A derivation does not need to directly ... More Accretion and emission processes in AGNJan 12 2001Jan 13 2001The UV-X continuum, the X-ray spectral features, and the variability in these bands provide powerful tools for studying the innermost regions of AGNs from which we gain an insight into the accretion process. In this chapter the discussion focusses on ... More A New Statistical Parser Based on Bigram Lexical DependenciesMay 06 1996This paper describes a new statistical parser which is based on probabilities of dependencies between head-words in the parse tree. Standard bigram probability estimation techniques are extended to calculate probabilities of dependencies between pairs ... More Some questions about the dimension of a group actionNov 14 2006We discuss three families of groups, $ZW_n$, $PL(I^n)$, and $PL(S^n)$ (the last two being families of groups of piecewise-linear homeomorphisms of standard $n$-dimensional spaces). We note that for all positive integers $n$, $ZW_n$ embeds in $PL(I^n)$ ... More Different approaches to TMD Evolution with scaleSep 18 2014Many apparently contradictory approaches to TMD factorization and its non-perturbative content exist. This talk evaluated the different methods and proposed tools for resolving the contradictions and experimentally adjudicating the results. Computable Stochastic ProcessesSep 15 2014Oct 13 2015The aim of this paper is to present an elementary computable theory of probability, random variables and stochastic processes. The probability theory is baed on existing approaches using valuations and lower integrals. Various approaches to random variables ... More Matter in a Warped and Oscillating BackgroundOct 25 2001We examine the role of matter in an oscillating background with a warped, compact extra dimension. This background is compatible with an S^1/Z_2 orbifold structure which allows chiral fermions to be included in the scenario. When the background oscillates ... More Brane Cosmologies without OrbifoldsMar 17 2000Jun 20 2000We study the dynamics of branes in configurations where 1) the brane is the edge of a single anti-de Sitter (AdS) space and 2) the brane is the surface of a vacuum bubble expanding into a Schwarzschild or AdS-Schwarzschild bulk. In both cases we find ... More Ideal structure of the C*-algebra of Thompson group TSep 29 2014Oct 06 2014In a recent paper Uffe Haagerup and Kristian Knudsen Olesen show that for Richard Thompson's group $T$, if there exists a finite set $H$ which can be decomposed as disjoint union of sets $H_1$ and $H_2$ with $\sum_{g\in H_1}\pi(g)=\sum_{h\in H_2}\pi(h)$ ... More The Fe II problem in NLS1sMay 08 2000For more than twenty years, strong Fe II emission lines have been observed in Active Galactic Nuclei and in particular in Narrow Line Seyfert 1 galaxies. A quick overview of the observations and of the models proposed to interpret the Fe II spectrum is ... More Curvature actions on Spin(n) bundlesSep 24 2001We compute the number of linearly independent ways in which a tensor of Weyl type may act upon a given irreducible tensor-spinor bundle V over a Riemannian manifold. Together with the analogous but easier problem involving actions of tensors of Einstein ... More Trans-Planckian enhancements of the primordial non-GaussianitiesMay 29 2009This article examines how breaking a Lorentz-invariant description of nature at tiny space-time intervals would affect the non-Gaussian character of the pattern of primordial perturbations left by inflation. We specifically study a set of irrelevant operators ... More Hopf-Frobenius algebras and a new Drinfeld doubleMay 02 2019The ZX-calculus and related theories are based on so-called interacting Frobenius algebras, where a pair of $\dag$-special commutative Frobenius algebras jointly form a pair of Hopf algebras. In this setting we introduce a generalisation of this structure, ... More SN1a Supernova Red ShiftsJan 05 2001Oct 05 2004Recent SN1a data have probed deeper into space than ever before. Plotted as distance vs. recession speed, a disturbing non-linearity is found which has led to speculations about "dark energy" which somehow acts like anti-gravity. This study finds a full ... More Log-canonical thresholds in real and complex dimension 2Jul 27 2017Feb 05 2018We study the set of log-canonical thresholds (or critical integrability indices) of holomorphic (resp. real analytic) function germs in $\mathbb{C}^2$ (resp. $\mathbb{R}^2$). In particular, we prove that the ascending chain condition holds, and that the ... More Stability and Convergence of the Sasaki-Ricci FlowMay 19 2011We introduce a holomorphic sheaf E on a Sasaki manifold and study two new notions of stability for E along the Sasaki-Ricci flow related to the `jumping up' of the number of global holomorphic sections of E at infinity. First, we show that if the Mabuchi ... More On the Compatibility Between Physics and Intelligent OrganismsFeb 09 2001It has been commonly argued, on the basis of Goedel's theorem and related mathematical results, that true artificial intelligence cannot exist. Penrose has further deduced from the existence of human intelligence that fundamental changes in physical theories ... More QCD and Hadronic Interactions: Summary talk for Moriond 97May 09 1997This talk covers a selection of topics that were discussed at this meeting in the non-heavy-ion sessions: (a) The high $Q^{2}$ events at HERA and their theoretical interpretation. (b) The issues of how well we know the predictions of QCD, with a particular ... More Physics of Polarized pp CollisionsSep 23 1993I will summarize the physics that can be investigated with polarized pp collisions. It is technically feasible to use the RHIC collider for accelerating highly polarized protons to a center-of-mass energy of about 400 GeV, with high luminosity. Such collisions ... More Equivelar toroids with few flag-orbitsFeb 21 2018An $(n+1)$-toroid is a quotient of a tessellation of the $n$-dimensional Euclidean space with a lattice group. Toroids are generalizations of maps in the torus on higher dimensions and also provide examples of abstract polytopes. Equivelar toroids are ... More An OpenMath Content Dictionary for Tensor ConceptsMay 24 2010We introduce a new OpenMath content dictionary, named tensor1, containing symbols for the expression of tensor formulas. These symbols support the expression of non-Cartesian coordinates and invariant, multilinear expressions in the context of coordinate ... More Gluing stability conditionsFeb 02 2009May 13 2010We define and study a gluing procedure for Bridgeland stability conditions in the situation when a triangulated category has a semiorthogonal decomposition. As an application we construct stability conditions on the derived categories of ${\mathbb{Z}}_2$-equivariant ... More What exactly is a parton density?Apr 12 2003Apr 28 2003I give an account of the definitions of parton densities, both the conventional ones, integrated over parton transverse momentum, and unintegrated transverse-momentum-dependent densities. The aim is to get a precise and correct definition of a parton ... More On some properties of orthogonal Weingarten functionsMar 30 2009We give a Fourier-type formula for computing the orthogonal Weingarten formula. The Weingarten calculus was introduced as a systematic method to compute integrals of polynomials with respect to Haar measure over classical groups. Although a Fourier-type ... More Random matrix techniques in quantum information theorySep 15 2015The purpose of this review article is to present some of the latest developments using random techniques, and in particular, random matrix techniques in quantum information theory. Our review is a blend of a rather exhaustive review, combined with more ... More Modular analogues of Jordan's theorem for finite linear groupsSep 20 2007In 1878, Jordan showed that a finite subgroup of GL(n,C) contains an abelian normal subgroup whose index is bounded by a function of n alone. Previously, the author has given precise bounds. Here, we consider analogues for finite linear groups over algebraically ... More Cost Sharing in the Aspnes Inoculation ModelFeb 10 2011We consider the use of cost sharing in the Aspnes model of network inoculation, showing that this can improve the cost of the optimal equilibrium by a factor of $O(\sqrt{n})$ in a network of $n$ nodes. Taming the alpha-vacuumDec 14 2003An interacting scalar field theory in de Sitter space is non-renormalizable for a generic alpha-vacuum state. This pathology arises since the usual propagator used allows for a constructive interference among propagators in loop corrections, which produces ... More An effective theory of initial conditions in inflationJul 07 2005We examine the renormalization of an effective theory description of a general initial state set in an isotropically expanding space-time, which is done to understand how to include the effects of new physics in the calculation of the cosmic microwave ... More Fast Recompilation of Object Oriented ModulesJun 10 2005Once a program file is modified, the recompilation time should be minimized, without sacrificing execution speed or high level object oriented features. The recompilation time is often a problem for the large graphical interactive distributed applications ... More The Randall-Sundrum Scenario with an Extra Warped DimensionMar 10 2001We investigate a scenario with two four-branes embedded in six dimensions. When the metric is periodic and compact in one of the dimensions parallel to the branes, the value of the effective cosmological constant for the remaining five dimensions can ... More A Gamma-Poisson Model for Normalizing Archaeological AssemblagesFeb 02 2016Weighting artifact counts in archaeology has typically followed either a spatial or frequency-based approach. The following paper proposes a Bayesian inferential model using the Poisson distribution to normalize counts of artifacts as a rate, when comparing ... More