Results for "George Christodoulides"

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Praaline: Integrating Tools for Speech Corpus ResearchFeb 08 2018This paper presents Praaline, an open-source software system for managing, annotating, analysing and visualising speech corpora. Researchers working with speech corpora are often faced with multiple tools and formats, and they need to work with ever-increasing ... More
DisMo: A Morphosyntactic, Disfluency and Multi-Word Unit Annotator. An Evaluation on a Corpus of French Spontaneous and Read SpeechFeb 08 2018We present DisMo, a multi-level annotator for spoken language corpora that integrates part-of-speech tagging with basic disfluency detection and annotation, and multi-word unit recognition. DisMo is a hybrid system that uses a combination of lexical resources, ... More
Observation of Bloch oscillations in complex PT-symmetric photonic latticesAug 31 2016Light propagation in periodic environments is often associated with a number of interesting and potentially useful processes. If a crystalline optical potential is also linearly ramped, light can undergo periodic Bloch oscillations, a direct outcome of ... More
Four Weak Gauge Boson Production at Photon Linear Collider and Heavy Higgs SignalJul 28 1994We study the signals and backgrounds for a heavy Higgs boson in the processes $\gamma\gamma\to WWWW$, $\gamma\gamma\to WWZZ$ at the photon linear collider. The results are based on the complete tree level SM calculation for these reactions. We show that ... More
Spatial Variations of the Extinction Law in the Galactic Disk from Infrared ObservationsJun 28 2016Infrared photometry in the J (1.2 microns), H (1.7 microns), Ks (2.2 microns) bands from the 2MASS catalogue and in the W1 (3.4 microns), W2 (4.6 microns), W3 (12 microns), W4 (22 microns) bands from the WISE catalogue is used to reveal the spatial variations ... More
The classical pion field in a nucleusNov 08 2007Sep 04 2008A self-consistent symmetry arises when the nucleon angular momentum j and the isospin t are coupled to a grand spin G. Closed G shells become sources of a classical pion field with a hedgehog shape. Although the amplitude of the pion field, as measured ... More
Doubles melanges des polylogarithmes multiples aux racines de l'unit'eFeb 15 2002The values at positive integers of the polyzeta functions are solutions of the polynomial equations arising from Drinfeld's associators, which have numerous applications in quantum algebra. Considered as iterated integrals they become periods of the motivic ... More
A Person Re-Identification System For Mobile DevicesDec 13 2015Person re-identification is a critical security task for recognizing a person across spatially disjoint sensors. Previous work can be computationally intensive and is mainly based on low-level cues extracted from RGB data and implemented on a PC for a ... More
Verso folio: Diversified Ranking for Large Graphs with Context-Aware ConsiderationsJul 25 2016This work is pertaining to the diversified ranking of web-resources and interconnected documents that rely on a network-like structure, e.g. web-pages. A practical example of this would be a query for the k most relevant web-pages that are also in the ... More
Connections Between Symmetries and Conservation LawsNov 09 2005This paper presents recent work on connections between symmetries and conservation laws. After reviewing Noether's theorem and its limitations, we present the Direct Construction Method to show how to find directly the conservation laws for any given ... More
Mass Determinations of Star ClustersJul 03 2001Mass determinations are difficult to obtain and still frequently characterised by deceptively large uncertainties. We review below the various mass estimators used for star clusters of all ages and luminosities. We highlight a few recent results related ... More
Mirror mesons at the Large Hadron Collider (LHC)Jun 23 2016The existence of mirror partners of Standard-Model fermions offers a viable alternative to a fundamental BEH mechanism, with the coupling corresponding to the gauged mirror generation symmetry becoming naturally strong at energies around 1 TeV. The resulting ... More
Automorphisms of an orthomodular poset of projectionsNov 29 2002Oct 07 2003By using a lattice characterization of continuous projections defined on a topological vector space E arising from a dual pair, we determine the automorphism group of their orthomodular poset Proj(E) by means of automorphisms and anti-automorphisms of ... More
A Bayesian Nonparametric IRT ModelFeb 11 2015This paper introduces a flexible Bayesian nonparametric Item Response Theory (IRT) model, which applies to dichotomous or polytomous item responses, and which can apply to either unidimensional or multidimensional scaling. This is an infinite-mixture ... More
Variations of the Interstellar Extinction Law within the Nearest KiloparsecJun 30 2016Multicolor photometry from the Tycho-2 and 2MASS catalogues for 11 990 OB and 30 671 K-type red giant branch stars is used to detect systematic large-scale variations of the interstellar extinction law within the nearest kiloparsec. The characteristic ... More
Some Properties of Dust Outside the Galactic DiskJun 28 2016The joint use of accurate near- and mid-infrared photometry from the 2MASS and WISE catalogues has allowed the variations of the extinction law and the dust grain size distribution in high Galactic latitudes (|b|>50) at distances up to 3 kpc from the ... More
Influence of the Gould Belt on Interstellar ExtinctionJun 30 2016A new analytical 3D model of interstellar extinction within 500 pc of the Sun as a function of the Galactic spherical coordinates is suggested. This model is physically more justified than the widely used Arenou model, since it takes into account the ... More
On the maximal operators of Walsh-Kaczmarz-Fejér meansOct 05 2014The main aim of this paper is to prove that the maximal operator $\sigma_{p}^{\kappa ,\ast }f:=\sup_{n\in \mathbf{P}}\left\vert \sigma_{n}^{\kappa }f\right\vert /\left( n+1\right) ^{1/p-2}$ is bounded from the Hardy space $% H_{p}$ to the space $L_{p},$ ... More
On The maximal operators of Vilenkin-Fejér means on Hardy spacesOct 05 2014The main aim of this paper is to prove that when $0<p<1/2$ the maximal operator $\overset{\sim }{\sigma }_{p}^{\ast }f:=\underset{n\in \mathbb{N}}{% \sup }\frac{\left\vert \sigma_{n}f\right\vert }{\left( n+1\right) ^{1/p-2}}$ is bounded from the martingale ... More
On the convergence of Fejér means of Walsh-Fourier series in the space $H_{p}$Sep 17 2014The main aim of this paper is to find the necessary and sufficient conditions for a modulus of continuity of a martingale $F\in H_{p},$ for which Fej\'er means convergence in $H_{p}$-norm, when $0<p\leq 1/2.$
Single or combined location measurements of the same parameter without prior probability. (Altern. title, Parametric inference as useful illusion; Part 1)Mar 28 2002May 13 2003Motivation. This version is based solely on the calculus of probability, excluding any statistical principle. "Location measurement" means the pdf of the error is known. When the datum is obtained, intuition suggests something like a pdf for the parameter; ... More
Projective Connections and the Algebra of DensitiesAug 20 2008Projective connections first appeared in Cartan's papers in the 1920's. Since then they have resurfaced periodically in, for example, integrable systems and perhaps most recently in the context of so called projectively equivariant quantisation. We recall ... More
Black Holes and Sphalerons in Low Energy Effective String TheoryOct 25 1994Talk given at the 7th Marcel Grossmann Meeting on General Relativity, Stanford University, July 24-30, 1994.
Quillen's adjunction theorem for derived functors, revisitedNov 30 2006The aim of this paper is to present a very simple original, purely formal, proof of Quillen's adjunction theorem for derived functors, and of some more recent variations and generalizations of this theorem. This is obtained by proving an abstract adjunction ... More
Nondifferentiable functions of one-dimensional semimartingalesFeb 04 2008Jan 26 2010We consider decompositions of processes of the form $Y=f(t,X_t)$ where $X$ is a semimartingale. The function $f$ is not required to be differentiable, so It\^{o}'s lemma does not apply. In the case where $f(t,x)$ is independent of $t$, it is shown that ... More
Quantization of maximally-charged slowly-moving black holesSep 15 2000Jan 11 2001We discuss the quantization of a system of slowly-moving extreme Reissner-Nordstrom black holes. In the near-horizon limit, this system has been shown to possess an SL(2,R) conformal symmetry. However, the Hamiltonian appears to have no well-defined ground ... More
Canonical quantization of a particle near a black holeJun 12 2000We discuss the quantization of a particle near an extreme Reissner-Nordstrom black hole in the canonical formalism. This model appears to be described by a Hamiltonian with no well-defined ground state. This problem can be circumvented by a redefinition ... More
Valley currents and non-local resistances of graphene nanostructures with broken inversion symmetry from the perspective of scattering theorySep 23 2015Valley currents and non-local resistances of graphene nanostructures with broken inversion symmetry are considered theoretically in the linear response regime. Scattering state wave functions of electrons entering the nanostructure from the contacts represented ... More
Ideal Spin Filters: Theoretical Study of Electron Transmission Through Ordered and Disordered Interfaces Between Ferromagnetic Metals and SemiconductorsOct 11 2000It is predicted that certain atomically ordered interfaces between some ferromagnetic metals (F) and semiconductors (S) should act as ideal spin filters that transmit electrons only from the majority spin bands or only from the minority spin bands of ... More
Why Are Large Persistent Currents Observed in Small Gold Rings?Jan 13 1995It is demonstrated using three-dimensional computer simulations that some simple non-interacting electron models that include electron scattering by grain boundaries, exhibit coexistence of large persistent currents and small conductances, similar to ... More
Congruences of the fork extensions. I. The Congruence Extension PropertyJul 02 2013Sep 08 2013For a slim, planar, semimodular lattice, G. Cz\'edli and E.\,T. Schmidt introduced the fork extension in 2012. In this note we prove that the fork extension has the Congruence Extension Property. This paper has been merged with Part II, under the title ... More
Congruences in slim, planar, semimodular lattices: The Swing LemmaDec 30 2014Apr 24 2015In an earlier paper, to describe how a congruence spreads from a prime interval to another in a finite lattice, I introduced the concept of prime-perspectivity and its transitive extension, prime-projectivity and proved the Prime-projectivity Lemma. In ... More
Sentient NetworksDec 13 1997In this paper we consider the question whether a distributed network of sensors and data processors can form "perceptions" based on the sensory data. Because sensory data can have exponentially many explanations, the use of a central data processor to ... More
Quantum Mechanics as Information FusionDec 04 1999We provide evidence that quantum mechanics can be interpreted as a rational algorithm for finding the least complex description for the correlations in the outputs of sensors in a large array. In particular, by comparing the self-organization approach ... More
A Natural Cosmological Model with Omega_matter <1Feb 12 1999Flat cosmological models with a cosmological constant on the order of the Einstein-de Sitter critical density are enigmatic in the sense that there does not appear to be any natural explanation for why there should be a cosmological constant with such ... More
The Black Hole Information Puzzle and Evidence for a Cosmological ConstantJul 22 1998Recent hints from observations of distant supernovae of a positive cosmological constant with magnitude comparable to the average density of matter seem to point in the direction of a two fluid model for spacetime; where the "normal" component consists ... More
The Monster Sporadic Group and a Theory Underlying Superstring ModelsSep 18 1996The pattern of duality symmetries acting on the states of compactified superstring models reinforces an earlier suggestion that the Monster sporadic group is a hidden symmetry for superstring models. This in turn points to a supersymmetric theory of self-dual ... More
Change Detection with Compressive MeasurementsApr 11 2014Quickest change point detection is concerned with the detection of statistical change(s) in sequences while minimizing the detection delay subject to false alarm constraints. In this paper, the problem of change point detection is studied when the decision ... More
Discussion of "Estimating the historical and future probabilities of large terrorist events" by Aaron Clauset and Ryan WoodardJan 10 2014Discussion of "Estimating the historical and future probabilities of large terrorist events" by Aaron Clauset and Ryan Woodard [arXiv:1209.0089].
Modeling and estimation of multi-source clustering in crime and security dataNov 28 2013While the presence of clustering in crime and security event data is well established, the mechanism(s) by which clustering arises is not fully understood. Both contagion models and history independent correlation models are applied, but not simultaneously. ... More
Three-Dimensional Reddening Map for Stars from 2MASS Photometry: The Method and the First ResultsJul 02 2016The first results of the construction of a 3D reddening map for stars within 1600 pc of the Sun are presented. Analysis of the distribution of 70 million stars from the 2MASS catalog with the most accurate photometry on the (J-Ks) - Ks diagram supplemented ... More
A counterexample to a question of Haydon, Odell and RosenthalOct 14 1996We give an example of a compact metric space $K$, an open dense subset $U$ of $K$, and a sequence $(f_n)$ in $C(K)$ which is pointwise convergent to a non-continuous function on $K$, such that for every $u \in U$ there exists $n \in \N$ with $f_n(u)=f_m(u)$ ... More
Resonant capture of multiple planet systems under dissipation and stable orbital configurationsApr 12 2016Migration of planetary systems caused by the action of dissipative forces may lead the planets to be trapped in a resonance. In this work we study the conditions and the dynamics of such resonant trapping. Particularly, we are interested in finding out ... More
Observation of Parity-Time Symmetry in Optically Induced Atomic LatticesApr 14 2016Nov 28 2016We experimentally demonstrate PT-symmetric optical lattices with periodical gain and loss profiles in a coherently-prepared four-level N-type atomic system. By appropriately tuning the pertinent atomic parameters, the onset of PT-symmetry breaking is ... More
Engineered optical nonlinearities and enhanced light transmission in soft-matter systems with tunable polarizabilitiesAug 14 2013In this work, we demonstrate that the nonlinear response of certain soft-matter systems can be tailored at will by appropriately engineering their optical polarizability. In particular, we deliberately synthesize stable colloidal suspensions with negative ... More
The Emergence of Norms via Contextual Agreements in Open SocietiesMar 24 2015This paper explores the emergence of norms in agents' societies when agents play multiple -even incompatible- roles in their social contexts simultaneously, and have limited interaction ranges. Specifically, this article proposes two reinforcement learning ... More
On satellites in arbitrary categoriesSep 09 2008We generalize the definition of satellites with respect to presheaves (and copresheaves) with trace in the sense of Inassaridze; a presheaf with trace is replaced by a graph with a pair of diagrams defined on it. We show that the right satellite functor ... More
Matching of analytical and numerical solutions for neutron stars of arbitrary rotationJan 29 2012We demonstrate the results of an attempt to match the two-soliton analytical solution with the numerically produced solutions of the Einstein field equations, that describe the spacetime exterior of rotating neutron stars, for arbitrary rotation. The ... More
The April First PhenomenonMar 28 2014A true quantum reason for why people fib on April first.
A toy quantum analog of enzymesOct 19 2015We present a quantum system incorporating qualitative aspects of enzyme action in which the possibility of quantum superposition of several conformations of the enzyme-substrate complex is investigated. We present numerical results showing quantum effects ... More
Comparison of the Pulkovo Compilation of Radial Velocities with the RAVE DR1 CatalogueJun 25 2016The Data Release 1 of the Radial-Velocity Experiment (RAVE DR1, 24 748 stars) is compared with the May 15, 2006 version of the Pulkovo Compilation of Radial Velocities (PCRV, 35 495 stars). RAVE DR1 includes mostly $9^m-13^m$ stars, while the PCRV contains ... More
Localizing subcategories in the bootstrap category of filtered C*-algebrasFeb 01 2016We use the abelian approximation for the bootstrap category of filtered C*-algebras to define a sensible notion of support for its objects. As a consequence, we provide a full classification of localizing subcategories in terms of a product of lattices ... More
H0 RevisitedNov 14 2013Feb 08 2014I reanalyse the Riess et al. (2011, hereafter R11) Cepheid data using the revised geometric maser distance to NGC 4258 of Humphreys et al. (2013). I explore different outlier rejection criteria designed to give a reduced chi-squared of unity and compare ... More
Normal Galaxies in the InfraredMay 09 2000This review addresses what can be learned from infrared observations about galaxies powered predominantly by star formation. Infrared techniques mostly probe the interstellar medium of galaxies, yielding physical and chemical information on the medium ... More
A note on the norm convergence by Vilenkin-Fejér meansFeb 14 2015The main aim of this paper is to find necessary and sufficient conditions for the convergence of Fej\'er means in terms of the modulus of continuity on the Hardy spaces $H_{p},$ when $0<p\leq 1/2.$
Approximation by Walsh-Kaczmarz-Fejér means on the Hardy spaceOct 05 2014The main aim of this paper is to find necessary and sufficient conditions for the convergence of Walsh-Kaczmarz-Fej\'er means in the terms of the modulus of continuity on the Hardy spaces $H_{p},$ when $0<p\leq 1/2.$
On the maximal operators of Walsh-Kaczmarz-Nörlund meansOct 05 2014Dec 25 2014The main aim of this paper is to investigate $\left( H_{p},L_{p,\infty }\right) $ type inequalities for maximal operators of N\"orlund means with monotone coefficients of one-dimensional Walsh-Kaczmarz system. By applying this results we conclude a.e ... More
On The maximal operators of Vilenkin-Fejér meansOct 05 2014The main aim of this paper is to prove that the maximal operator $\overset{% \sim }{\sigma }^{*}f:=\underset{n\in P}{\sup }\frac{\left| \sigma_{n}f\right| }{\log ^{2}\left( n+1\right) }$ is bounded from the Hardy space $H_{1/2}$ to the space $L_{1/2}$, ... More
Strong convergence theorems of Walsh-Fejér meansOct 05 2014As main result we prove that Fej\'er means of Walsh-Fourier series are uniformly bounded operators from $\ H_{p}$ to $H_{p}$ $\left( 0<p\leq 1/2\right) .
A note on the Fourier coefficients and partial sums of Vilenkin-Fourier seriesOct 05 2014The main aim of this paper is to investigate Paley type and Hardy-Littlewood type inequalities and strong convergence theorem of partial sums of Vilenkin-Fourier series.
Survival exponents for some Gaussian processesMar 12 2012The problem is a power-law asymptotics of the probability that a self-similar process does not exceed a fixed level during long time. The exponent in such asymptotics is estimated for some Gaussian processes, including the fractional Brownian motion (FBM) ... More
Properties of Expectations of Functions of Martingale DiffusionsJan 02 2008Given a real valued and time-inhomogeneous martingale diffusion X, we investigate the properties of functions defined by the conditional expectation f(t,X_t)=E[g(X_T)|F_t]. We show that whenever g is monotonic or Lipschitz continuous then f(t,x) will ... More
A Generalized Backward Equation For One Dimensional ProcessesMar 23 2008Aug 17 2008Suppose that a real valued process X is given as a solution to a stochastic differential equation. Then, for any twice continuously differentiable function f, the backward Kolmogorov equation gives a condition for f(t,X) to be a local martingale. We generalize ... More
On the homotopy type of certain cobordism categories of surfacesAug 30 2010Mar 14 2011Let $\mathcal{A}_{g,d}$ be the (topological) cobordism category of orientable surfaces whose connected components are homeomorphic to either $S^1 \times I$ with one incoming and one outgoing boundary component or the surface $\Sigma_{g,d}$ of genus $g$ ... More
On the Cofibrant Generation of Model CategoriesJul 16 2009The paper studies the problem of the cofibrant generation of a model category. We prove that, assuming Vop\v{e}nka's principle, every cofibrantly generated model category is Quillen equivalent to a combinatorial model category. We discuss cases where ... More
Projective Connections and Schwarzian Derivatives for Supermanifolds, and Batalin-Vilkovisky OperatorsSep 29 2009We extend the notion of a Thomas projective connection (a projective equivalence class of linear connections) for supermanifolds. As a by-product, we arrive at a generalisation of the multidimensional Schwarzian derivative for the super case which was ... More
A Canonical Laplacian on the Algebra of Densities on a Projectively Connected ManifoldSep 29 2009On a manifold with a projective connection we canonically assign a second order differential operator acting on the algebra of all densities to any tensor density $S^{ij}$ of fixed weight $\lambda$. In particular, this implies that on any projectively ... More
Some Early Ideas on the Metric Geometry of ThermodynamicsApr 09 2016It is a pleasure to write for this 90'th anniversary volume of Journal of Low Temperature Physics dedicated to Horst Meyer at Duke University. I was a PhD student with Horst in the period 1975-1980, working in experimental low temperature physics. While ... More
Notes on the vector adelic GrassmannianJun 23 2015These are notes about the connection between the Gibbons-Hermsen system and the multi-component KP hierarchy: they were intended as a first sketch of a paper on that subject, but since it seems unlikely that I will ever write such a paper I have decided ... More
On the quadratic action of the Hawking-Turok instantonApr 22 1998May 01 1998Positive definiteness of the quadratic part of the action of the Hawking-Turok instanton is investigated. The Euclidean quadratic action for scalar perturbations is expressed in terms of a single gauge invariant quantity $q$. The mode functions satisfy ... More
On instability of Rubakov-Shaposhnikov modelFeb 24 2010Instability of 6 dimensional Rubakov-Shaposhnikov model is reinvestigated. It is shown that the model is unstable in scalar perturbations sector with very particular instability pattern: there are no unstable modes for the first two lowest angular harmonics, ... More
Gravitating, Gravitational and Dilatonic SphaleronsAug 05 1995This is a brief review of the main properties of sphalerons in various theories with a Yang--Mills field. Talk given at the Heat Kernel Techniques and Quantum Gravity, Winnipeg, Canada, August 2-6, 1994.
Magnetic spin excitations in diluted ferromagnetic systems: the case of $Ga_{1-x}Mn_{x}As$Oct 17 2006Jul 11 2007We propose a theory which allow to calculate the magnetic excitation spectrum in diluted ferromagnetic systems. The approach is rather general and based on the Self-Consistent local Random Phase Approximation in which disorder (dilution) and thermal fluctuations ... More
Consistency Strengths of Modified Maximality PrinciplesJun 03 2004The Maximality Principle MP is a scheme which states that if a sentence of the language of ZFC is true in some forcing extension V^P, and remains true in any further forcing extension of V^P, then it is true in all forcing extensions of V. A modified ... More
Non-Noether symmetries in singular dynamical systemsJun 15 2001Jul 22 2002It's well known that Noether symmetries lead to the conservation laws. Conserved quantities are constructed out of generator of the symmetry - invariant Hamiltonian vector field. Considering more general class of vector fields - non-Hamiltonian ones leads ... More
Rashba-Dirac cones at the tungsten surface: Insights from a tight-binding model and thin film subband structureNov 11 2016A tight-binding model of bcc tungsten that includes spin-orbit coupling is developed and applied to the surface states of (110) tungsten thin films. The model describes accurately the anisotropic Dirac cone-like dispersion and Rashba-like spin polarization ... More
On the appearance of compact objects at radio and optical frequenciesJun 25 2009In the dark energy star picture a compact object is transparent at radio and optical frequencies, and acts as a defocusing lens. Thus the object itself appears as a luminous disk whose surface brightness reflects the surface brightness of the background. ... More
Blueprint for a rotating UniversAug 17 2006Aug 24 2006A solution of the vacuum Einstein equations with a cosmological constant is exhibited which can perhaps be used to describe the interior of compact rotating objects, and may also provide a description of our universe on length scales approaching the size ... More
Quantum Criticality and the Alpha/Delta PuzzleOct 11 2008In this paper we suggest a novel explanation for the alpha-delta transition in plutonium based on an analogy between the evolution of the actinide ground state as a function of spin orbit coupling and the behaviour of thin film superconductors in a magnetic ... More
Locally Contractive Maps on Perfect Polish Ultrametric SpacesFeb 12 2015May 01 2015In this paper we present a result concerning locally contractive maps defined on subsets of perfect Polish ultrametric spaces (i.e. separable complete ultrametric spaces). Specifically, we show that a perfect compact ultrametric space cannot be contained ... More
Univariate error function based neural network approximationApr 24 2014Here we research the univariate quantitative approximation of real and complex valued continuous functions on a compact interval or all the real line by quasi-interpolation, Baskakov type and quadrature type neural network operators. We perform also the ... More
Representing finite distributive lattices as congruence lattices of latticesSep 28 2013Dilworth's theorem. Every finite distributive lattice $D$ can be represented as the congruence lattice of a finite lattice $L$. We want: Every finite distributive lattice $D$ can be represented as the congruence lattice of a nice finite lattice $L$. nice ... More
Grothendieck $\infty$-groupoids, and still another definition of $\infty$-categoriesSep 13 2010The aim of this paper is to present a simplified version of the notion of $\infty$-groupoid developed by Grothendieck in "Pursuing Stacks" and to introduce a definition of $\infty$-categories inspired by Grothendieck's approach.
Thinking locally: reflections on Dynamical Mean-Field Theory from a high-temperature/high energy perspectiveDec 22 2011When spatial correlations are short-range, the physics of strongly correlated systems is controlled by local quantum fluctuations. In those regimes, Dynamical Mean-Field Theory can be viewed as a `compass' which provides guidance on the relevant degrees ... More
Quantized Detector Networks: A review of recent developmentsSep 26 2007QDN (quantized detector networks) is a description of quantum processes in which the principal focus is on observers and their apparatus, rather than on states of SUOs (systems under observation). It is a realization of Heisenberg's original instrumentalist ... More
The running of the Universe and the quantum structure of timeMay 04 2001May 14 2001Some principles underpinning the running of the Universe are discussed. The most important, the machine principle, states that the Universe is a fully autonomous, self-organizing and self-testing quantum automaton. Continuous space and time, consciousness ... More
Discrete spacetime: classical causality,prediction, retrodiction and the mathematical arrow of timeApr 08 2000A mathematical definition of classical causality over discrete spacetime dynamics is formulated. The approach is background free and permits a definition of causality in a precise way whenever the spacetime dynamics permits. It gives a natural meaning ... More
Time-dependent diffusion in A-starsMay 05 1998Each time diffusion of elements is invoked in explaining abundance anomalies in a star, this supposes implicitly that a stratification process is in progress somewhere in that star. This means also, that the element abundances can still be evolving according ... More
A Hennings TQFT Construction for Quasi-Hopf AlgebrasNov 22 2013We extend the construction of the Hennings TQFT for ribbon Hopf algebras to the case of ribbon quasi-Hopf algebras as defined by Drinfeld. Calculations proceed in a similar fashion to the ordinary Hopf algebra case, but also require the handling of the ... More
Sum of many dilatesFeb 19 2014Aug 19 2015We show that for any coprime integers $\lambda_1 , \ldots , \lambda_k$ and any finite $A \subset \mathbb{Z}$, one has $$|\lambda_1 \cdot A + \ldots + \lambda_k \cdot A| \geq (|\lambda_1| + \ldots + |\lambda_k|)|A|- C,$$ where $C$ only depends on $\lambda_1 ... More
Eigenvalues of the basic Dirac operator on quaternion-Kahler foliationsJul 02 2007In this paper, we give an optimal lower bound for the eigenvalues of the basic Dirac operator on a quaternion-Kahler foliation. The limiting case is characterized by the existence of quaternion-Kahler Killing spinors. We end this paper by giving some ... More
Some applications of the Kohn-Rossi extension theoremsJun 02 1997We prove extension results for meromorphic functions by combining the Kohn-Rossi extension theorems with Andreotti's theory on the algebraic and analytic dependence of meromorphic functions on pseudoconcave manifolds. Versions of Kohn-Rossi theorems for ... More
The notion of Infinity within the Zermelo system and its relation to the Axiom of Countable ChoiceAug 27 2015In this article we consider alternative definitions-descriptions of a set being Infinite within the primitive Axiomatic System of Zermelo.
The Future of CosmologyDec 10 2007Jan 04 2008This article is the written version of the closing talk presented at the conference `A Century of Cosmology' held at San Servolo, Italy, in August 2007. I focus on the prospects of constraining fundamental physics from cosmological observations, using ... More
Principal Component Analysis of the Cosmic Microwave Background Anisotropies: Revealing The Tensor DegeneracySep 10 2001A principal component analysis of cosmic microwave background (CMB) anisotropy measurements is used to investigate degeneracies among cosmological parameters. The results show that a degeneracy with tensor modes -- the `tensor degeneracy' -- dominates ... More
On the centralizer of the sum of commuting nilpotent elementsDec 14 2004Oct 23 2005Let X and Y be commuting nilpotent K-endomorphisms of a vector space V, where K is a field of characteristic p >= 0. If F=K(t) is the field of rational functions on the projective line, consider the K(t)-endomorphism A=X+tY of V. If p=0, or if the (p-1)-st ... More
On the partial sums of Vilenkin-Fourier seriesOct 05 2014The main aim of this paper is to investigate weighted maximal operators of partial sums of Vilenkin-Fourier series. We also use our results to prove approximation and strong convergence theorems on the martingale Hardy spaces $H_{p},$ when $0<p\leq 1.$ ... More
A note on the strong convergence of two-dimensional Walsh-Fourier seriesOct 05 2014The main aim of this paper is to investigate the quadratical partial sums of the two-dimensional Walsh-Fourier series.
Four Weak Boson Production in Tev Photon--Photon Collisions and Heavy Higgs SignalJun 26 1994We study the signals for a heavy Higgs boson in the processes $\gamma\gamma\to WWWW$, $\gamma\gamma\to WWZZ$ at the photon linear collider. The results are based on the first complete tree level calculation for these reactions. Using a forward ``spectator" ... More
An Alternative Method to Obtain the Quark Polarization of the NucleonDec 11 2000An alternate method is described to extract the quark contribution to the spin of the nucleon directly from the first moment of the deuteron structure function, $g^d_1$. It is obtained without recourse to the use of input on the nucleon wave function ... More