Results for "Abdessatar Barhoumi"

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Phase transitions for Quantum Markov Chains associated with Ising type models on a Cayley treeMay 15 2016The main aim of the present paper is to prove the existence of a phase transition in quantum Markov chain (QMC) scheme for the Ising type models on a Cayley tree. Note that this kind of models do not have one-dimensional analogous, i.e. the considered ... More
Identification of the theory of multidimensional orthogonal polynomials with the theory of symmetric interacting Fock spaces with finite dimensional one particle spaceMar 10 2014Sep 01 2016The identification mentioned in the title allows a formulation of the multidi mensional Favard Lemma different from the ones currently used in the literature and which exactly parallels the original one dimensional formulation in the sense that the positive ... More
Phase Transitions for quantum Ising model with competing XY -interactions on a Cayley treeFeb 08 2019The main aim of the present paper is to establish the existence of a phase transition for the quantum Ising model with competing XY interactions within the quantum Markov chain (QMC) scheme. In this scheme, we employ the $C^*$-algebraic approach to the ... More
Recovery of small electromagnetic inhomogeneities from boundary measurements in time-dependent Maxwell's equationsJun 01 2007We consider for the time-dependent Maxwell's equations the inverse problem of identifying locations and certain properties of small electromagnetic inhomogeneities in a homogeneous background medium from dynamic measurements of the tangential component ... More
Quantum Markov States on Cayley treesFeb 08 2019It is known that any locally faithful quantum Markov state (QMS) on one dimensional setting can be considered as a Gibbs state associated with Hamiltonian with commuting nearest-neighbor interactions. In our previous results, we have investigated quantum ... More
Asymptotic behaviors for eigenvalues and eigenfunctions associated to Stokes operator in the presence of small boundary perturbationsSep 07 2015Feb 09 2016We consider the Stokes eigenvalue problem in a bounded domain of R3 with Dirich- let boundary conditions. The aim of this paper is to advance the development of high-order terms in the asymptotic expansions of the boundary perturbations of eigen- values, ... More
On the perturbation of the electromagnetic energy due to the presence of inhomogeneities with small diametersMay 31 2007We consider solutions to the time-harmonic Maxwell problem in $\R^3$. For such solution we provide a rigorous derivation of the asymptotic expansions in the practically interesting situation, where a finite number of inhomogeneities of small diameter ... More
A penalised model reproducing the mod-Poisson fluctuations in the Sathe-Selberg theoremJan 12 2017We construct a probabilistic model for the number of divisors of a random uniform integer that converges in the mod-Poisson sense to the same limiting function as its original counterpart, the one arising in the Sathe-Selberg theorem. This construction ... More
On Stein's method and mod-* convergenceJan 11 2017Stein's method allows to prove distributional convergence of a sequence of random variables and to quantify it with respect to a given metric such as Kolmogorov's (a Berry-Ess\'een type theorem). Mod-* convergence quantifies the convergence of a sequence ... More
Extreme value statistics for the roots of a complex Kac polynomialJun 22 2017We investigate the fluctuations and large deviations of the root of largest modulus in a model of random polynomial with independent complex Gaussian coefficients (Kac polynomials). The fluctuations were recently computed by R. Butez (arxiv 1704.02761) ... More
Random characters under the $L$-measure, I : Dirichlet charactersJan 16 2017We define the $L$-measure on the set of Dirichlet characters as an analogue of the Plancherel measure, once considered as a measure on the irreducible characters of the symmetric group. We compare the two measures and study the limit in distribution of ... More
Reconstruction of a complex electromagnetic coefficient from partial measurementsFeb 08 2017We consider an inverse boundary value problem for the Maxwell equations with boundary data assumed known only in accessible part $\Gamma$ of the boundary. We aim to prove a uniqueness result using the Dirichlet to Neumann data with measurements limited ... More
Determination of small linear perturbations in the diffusion coefficient from partial dynamic boundary measurementsFeb 07 2016This work deals with an inverse boundary value problem arising from the equation of heat conduction. We reconstruct small perturbations of the (isotropic) heat conductivity distribution from partial (on accessible part of the boundary) dynamic boundary ... More
Theorical and Numerical Analysis of the Rapid Pointwise Stabilization of Coupled String-Beam SystemsMay 24 2011We consider a pointwise stabilization problem for a coupled wave and plate equations. We prove under rather general assumptions, that such systems can stabilized so as to have arbitrarily high decay rates and are exactly controllable. We propose a numerical ... More
Inverse Conduction Problem for a Parabolic Equation using a Boundary Integral MethodMay 05 2008In this paper, a boundary integral method is used to solve an inverse linear heat conduction problem in two-dimensional bounded domain. An inverse problem of measuring the heat flux from partial (on part of the boundary) dynamic boundary measurements ... More
Construction of a new class of quantum Markov fieldsDec 16 2016In the present paper, we propose a new construction of quantum Markov fields on arbitrary connected, infinite, locally finite graphs. The construction is based on a specific tessellation on the considered graph, that allows us to express the Markov property ... More
Seuillage par hystérésis pour le test de photo-consistance des voxels dans le cadre de la reconstruction 3DSep 17 2018Voxel coloring is a popular method of reconstructing a three-dimensional surface model from a set of calibrated 2D images. However, the reconstruction quality is largely dependent on a thresholding procedure allowing the authors to decide, for each voxel, ... More
Quantum Markov Chains: A unification approachNov 01 2018In the present paper we study a unified approach for Quantum Markov Chains. A new quantum Markov property that generalizes the old one, is discussed. We introduce Markov states and chains on general local algebras, possessing a generic algebraic property, ... More
Identifying of the refractive index for the acoustic equation at fixed frequencyApr 16 2008In this paper we determine a formula for calculating the refractive index ${\bf n}$ for the acoustic equation from the partial Dirichlet to Neumann map(DN) associated to ${\bf n}$. We apply these results to identify locations and values of small volume ... More
A vectorial Ingham-Beurling theoremMar 19 2009Baiocchi et al. generalized a few years ago a classical theorem of Ingham and Beurling by means of divided differences. The optimality of their assumption has been proven by the third author of this note. The purpose of this note to extend these results ... More
Bivariate fluctuations for the number of arithmetic progressions in random setsFeb 11 2019We study arithmetic progressions $\{a,a+b,a+2b,\dots,a+(\ell-1) b\}$, with $\ell\ge 3$, in random subsets of the initial segment of natural numbers $[n]:=\{1,2,\dots, n\}$. Given $p\in[0,1]$ we denote by $[n]_p$ the random subset of $[n]$ which includes ... More
On the number of zeros of linear combinations of independent characteristic polynomials of random unitary matricesJan 22 2013We show that almost all the zeros of any finite linear combination of independent characteristic polynomials of random unitary matrices lie on the unit circle. This result is the random matrix analogue of an earlier result by Bombieri and Hejhal on the ... More
Use of multiple singular value decompositions to analyze complex intracellular calcium ion signalsSep 28 2010We compare calcium ion signaling ($\mathrm {Ca}^{2+}$) between two exposures; the data are present as movies, or, more prosaically, time series of images. This paper describes novel uses of singular value decompositions (SVD) and weighted versions of ... More
Hydrogen Burning of 17-O in Classical NovaeJun 21 2005We report on the observation of a previously unknown resonance at E=194.1+/-0.6 keV (lab) in the 17-O(p,alpha)14-N reaction, with a measured resonance strength omega_gamma(p,alpha)=1.6+/-0.2 meV. We studied in the same experiment the 17-O(p,gamma)18-F ... More
New measurement and analysis of the 7Be(p,gamma)8B cross sectionDec 10 1997Cross sections for the 7Be(p,gamma)8B reaction have been measured for E_c.m.= 0.35-1.4 MeV using radioactive 7Be targets. Two independent measurements carried out with different beam conditions, different targets and detectors are in excellent agreement. ... More
Low energy measurement of the 7Be(p,gamma)8B cross sectionJan 31 2001We have measured the cross section of the 7Be(p,gamma)8B reaction for E_cm = 185.8 keV, 134.7 keV and 111.7 keV using a radioactive 7Be target (132 mCi). Single and coincidence spectra of beta^+ and alpha particles from 8B and 8Be^* decay, respectively, ... More