Results for "Cédric Bomme"

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Photophysics of indole upon x-ray absorptionFeb 08 2018A photofragmentation study of gas-phase indole (C$_8$H$_7$N) upon single-photon ionization at a photon energy of 420 eV is presented. Indole was primarily inner-shell ionized at its nitrogen and carbon $1s$ orbitals. Electrons and ions were measured in ... More
Collision dynamics of two $^{238}$U atomic nucleiApr 20 2009Jun 02 2009Collisions of actinide nuclei form, during very short times of few $10^{-21}$ s, the heaviest ensembles of interacting nucleons available on Earth. Such very heavy ions collisions have been proposed as an alternative way to produce heavy and superheavy ... More
On properties of (weakly) small groupsApr 02 2011A group is small if it has countably many complete $n$-types over the empty set for each natural number n. More generally, a group $G$ is weakly small if it has countably many complete 1-types over every finite subset of G. We show here that in a weakly ... More
Inferring effective field observables from a discrete modelNov 16 2015Nov 05 2016A spin system on a lattice can usually be modelled at large scales by an effective quantum field theory. A key mathematical result relating the two descriptions is the quantum central limit theorem, which shows that certain spin observables satisfy an ... More
Vogan classes and cells in the unequal parameter caseMay 26 2014Jul 11 2014Kazhdan and Lusztig proved that Vogan classes are unions of cells in the equal parameter case. We extend this result in the unequal parameter case.
Blocks of the Grothendieck ring of equivariant bundles on a finite groupMay 22 2014Sep 11 2015If $G$ is a finite group, the Grothendieck group ${\mathbf{K}}\_G(G)$ of the category of $G$-equivariant ${\mathbb{C}}$-vector bundles on $G$ (for the action of $G$ on itself by conjugation) is endowed with a structure of (commutative) ring. If $K$ is ... More
A note on the wellposedness of scalar brane world cosmological perturbationsSep 29 2004Dec 22 2004We discuss scalar brane world cosmological perturbations for a 3-brane world in a maximally symmetric 5D bulk. We show that Mukoyama's master equations leads, for adiabatic perturbations of a perfect fluid on the brane and for scalar field matter on the ... More
Analytic semigroups on vector valued noncommutative $L^p$-spacesNov 14 2012Feb 13 2015We give sufficient conditions on an operator space $E$ and on a semigroup of operators on a von Neumann algebra $M$ to obtain a bounded analytic or a $R$-analytic semigroup $(T_t \otimes Id_E)_{t \geq 0}$ on the vector valued noncommutative $L^p$-space ... More
Fields and rings with few typesApr 02 2011Let R be an associative ring with possible extra structure. R is said to be weakly small if there are countably many 1-types over any finite subset of R. It is locally P if the algebraic closure of any finite subset of R has property P. It is shown here ... More
Perturbative quantum error correctionFeb 18 2011Jul 04 2011We derive simple necessary and sufficient conditions under which a quantum channel obtained from an arbitrary perturbation from the identity can be reversed on a given code to the lowest order in fidelity. We find the usual Knill-Laflamme conditions applied ... More
Particle number fluctuations and correlations in transfer reactions obtained using the Balian-Vénéroni variational principleNov 10 2010Feb 21 2011The Balian-V\'en\'eroni (BV) variational principle, which optimizes the evolution of the state according to the relevant observable in a given variational space, is used at the mean-field level to determine the particle number fluctuations in fragments ... More
The nucleon spin decomposition: news and experimental implicationsJan 16 2014Recently, many nucleon spin decompositions have been proposed in the literature, creating a lot of confusion. This revived in particular old controversies regarding the measurability of theoretically defined quantities. We propose a brief overview of ... More
The gauge-invariant canonical energy-momentum tensorJan 08 2016The canonical energy-momentum tensor is often considered as a purely academic object because of its gauge dependence. However, it has recently been realized that canonical quantities can in fact be defined in a gauge-invariant way provided that strict ... More
Canonical and kinetic decompositions of the proton spinFeb 01 2013We propose a short summary of the present situation concerning the proton spin decomposition. We briefly discuss some of the main controversies about the issues of gauge invariance, uniqueness and measurability. As a conclusion, we argue that part of ... More
Exotic and Non-Exotic Baryon Properties on the Light ConeOct 08 2010We present an extensive study of the static properties of light exotic and non-exotic baryons, based on the formulation of chiral quark-soliton model in terms of light-cone wave functions. We discuss in particular vector, axial and tensor charges as well ... More
Electromagnetic Properties for Arbitrary Spin Particles: Part 2 $-$ Natural Moments and Transverse Charge DensitiesJan 27 2009In a set of two papers, we propose to study an old-standing problem, namely the electromagnetic interaction for particles of arbitrary spin. Based on the assumption that light-cone helicity at tree level and $Q^2=0$ should be conserved non-trivially by ... More
Application of Polynomial Optimization to Electricity Transmission NetworksAug 12 2016Transmission system operators need to adapt their decision-making tools to the technological evolutions of the twenty first century. A computation inherent to most tools seeks to find alternating-current power flows that minimize power loss or generation ... More
Representation theory of Mantaci-Reutenauer algebrasMay 23 2006Jul 12 2006We study some aspects of the representation theory of Mantaci-Reutenauer algebras: Cartan matrix, Loewy length, modular representations.
On the character ring of a finite groupApr 10 2006Let $G$ be a finite group and let $k$ be a sufficiently large finite field. Let $R(G)$ denote the character ring of $G$ (i.e. the Grothendieck ring of the category of ${\mathbb{C}}G$-modules). We study the structure and the representations of the commutative ... More
Non-asymptotically flat black holes/branesSep 09 2004In the framework of string-inspired dilatonic gravity theories (from 4 to $D$ space-time dimensions), we construct new non-asymptotically flat black hole or black brane solutions. For particular values of the dilatonic coupling constant, we generalize ... More
Constructible characters and b-invariantsFeb 12 2013May 28 2015To each finite Coxeter system (W,S) and to each weight function L, Lusztig has defined the notions of constructible characters and of Lusztig families of W, using the so-called J-induction. Whenever L is constant, and using a general argument, Lusztig ... More
Enhanced Higgs-Mediated Lepton-Flavour-Violating Processes in the Supersymmetric Inverse Seesaw ModelMay 29 2012We study the impact of the inverse seesaw mechanism on several leptonic and hadronic low-energy flavour-violating observables in the context of the Minimal Supersymmetric Standard Model. Indeed, the contributions of the light right-handed sneutrinos from ... More
Causal structure of the entanglement renormalization ansatzOct 21 2011Mar 03 2013We show that the multiscale entanglement renormalization ansatz (MERA) can be reformulated in terms of a causality constraint on discrete quantum dynamics. This causal structure is that of de Sitter space with a flat spacelike boundary, where the volume ... More
Small skew fieldsApr 02 2011Wedderburn showed in 1905 that finite fields are commutative. As for infinite fields, we know that superstable (Cherlin, Shelah) and supersimple (Pillay, Scanlon, Wagner) ones are commutative. In their proof, Cherlin and Shelah use the fact that a superstable ... More
A remark on Cantor derivativeApr 02 2011It is shown that, modulo an equivalence relation induced by finite correspondences preserving Cantor rank, the class of topological spaces is an integral semi-ring on which the Cantor derivative is precisely a derivation.
A progenerator for representations of SL(n,q) in transverse characteristicMar 21 2011Let G=GL(n,q), SL(n,q) or PGL(n,q) where q is a power of some prime number p, let U denote a Sylow p-subgroup of G and let R be a commutative ring in which p is invertible. Let D(U) denote the derived subgroup of U and let e be the central primitive idempotent ... More
On Matsaev's conjecture for contractions on noncommutative $L^p$-spacesSep 07 2010Nov 12 2012We exhibit large classes of contractions on noncommutative $L^p$-spaces which satisfy the noncommutative analogue of Matsaev's conjecture, introduced by Peller, in 1985. In particular, we prove that every Schur multiplier on a Schatten space $S^p$ induced ... More
Particle transfer reactions with the time-dependent Hartree-Fock theory using a particle number projection techniqueAug 18 2010Nov 08 2010A particle-number projection technique is used to calculate transfer probabilities in the $^{16}$O+$^{208}$Pb reaction below the fusion barrier. The time evolution of the many-body wave function is obtained with the time-dependent Hartree-Fock (TDHF) ... More
On a conjecture of Pisier on the analyticity of semigroupsMar 26 2014Feb 12 2015We show that the analyticity of semigroups $(T_t)_{t \geq 0}$ of selfadjoint contractive Fourier multipliers on $L^p$-spaces of compact abelian groups is preserved by the tensorisation of the identity operator of a Banach space for a large class of K-convex ... More
Dilations of semigroups on von Neumann algebras and noncommutative $L^p$-spacesMar 15 2016Jun 13 2016We prove that any $w^*$-continuous semigroup of factorizable Markov maps acting on a von Neumann algebra $M$ equipped with a state can be dilated by a group of Markov $*$-automorphisms in a manner analogous to the discrete case of one factorizable Markov ... More
Tensor charges of light baryons in the Infinite Momentum FrameAug 30 2007We have used the Chiral-Quark Soliton Model formulated in the Infinite Momentum Frame to investigate the octet, decuplet and antidecuplet tensor charges up to the 5Q level. Using flavor SU(3) symmetry we have obtained for the proton $\delta u=1.172$ and ... More
Orbital angular momentum in the nucleonsJun 26 2014In the last decade, it has been realized that the orbital angular momentum of partons inside the nucleon plays a major role. It contributes significantly to nucleon properties and is at the origin of many asymmetries observed in spin physics. It is therefore ... More
Spin-orbit correlations in the nucleonJan 30 2014Jun 24 2014We investigate the correlations between the quark spin and orbital angular momentum inside the nucleon. Similarly to the Ji relation, we show that these correlations can be expressed in terms of specific moments of measurable parton distributions. This ... More
Gauge-covariant canonical formalism revisited with application to the proton spin decompositionFeb 22 2013Aug 15 2013We revisit the gauge-covariant canonical formalism by separating explicitly physical and gauge degrees of freedom. We show in particular that the gauge-invariant linear and angular momentum operators proposed by Chen et al. can consistently be derived ... More
Wilson lines and orbital angular momentumOct 09 2012Jan 07 2013We present an explicit realization of the Chen et al. approach to the proton spin decomposition in terms of Wilson lines, generalizing the light-front gauge-invariant extensions discussed recently by Hatta. Particular attention is drawn to the residual ... More
Noncommutative Figa-Talamanca-Herz algebras for Schur multipliersNov 23 2009Sep 23 2011We introduce a noncommutative analogue of the Fig\'a-Talamanca-Herz algebra $A_p(G)$ on the natural predual of the operator space $\frak{M}_{p,cb}$ of completely bounded Schur multipliers on Schatten space $S_p$. We determine the isometric Schur multipliers ... More
Exploring the proton spin structureApr 20 2015Understanding the spin structure of the proton is one of the main challenges in hadronic physics. While the concepts of spin and orbital angular momentum are pretty clear in the context of non-relativistic quantum mechanics, the generalization of these ... More
Néron's pairing and relative algebraic equivalenceMar 02 2011Let R be a complete discrete valuation ring with algebraically closed residue field k and fraction field K. Let X_K be a projective smooth and geometrically connected scheme over K. N\'eron defined a canonical pairing on X_K between 0-cycles of degree ... More
Semi-factorial models and Néron modelsMar 02 2011Let S be the spectrum of a discrete valuation ring with function field K. Let X be a scheme over S. We will say that X is semi-factorial over S if each invertible sheaf on the generic fiber X_K can be extended to an invertible sheaf on X. Here we show ... More
On Kazhdan-Lusztig cells in type BJun 02 2008Jan 14 2009We prove that, for any choice of parameters, the Kazhdan-Lusztig cells of a Weyl group of type $B$ are unions of combinatorial cells (defined using the domino insertion algorithm).
Semi-continuité des cellules de Kazhdan-LusztigMay 20 2008Computations in small Coxeter groups and infinite dihedral groups suggest that Kazhdan-Lusztig cells for unequal parameters obey to some "semicontinuity" phenomenon (as the parameter vary). The aim of this paper is to provide a rigorous theoretical background ... More
Two-sided cells in type $B$ (asymptotic case)Feb 04 2005Jun 30 2006We compute two-sided cells of Weyl groups of type $B$ for the "asymptotic" choice of parameters. We also obtain some partial results concerning Kazhdan-Lusztig conjectures in this particular case.
Information flow at the quantum-classical boundaryJan 23 2009We study the nature of the information preserved by a quantum channel via the observables which exist in its image (in the Heisenberg picture), and can therefore be simulated on the receiver's side. The sharp observables preserved by a channel form an ... More
Width of the analyticity strip in space variable of viscous Burgers shockwavesMar 20 2008May 06 2008Analytic continuation of viscous shock solution for the generalized Burgers equation with polynomial nonlinear source term is investigated. We show that a pertubated wave recovers its analyticity in the space variable in the strip limited by the first ... More
Cells and cactiJun 25 2015Oct 16 2015Let $(W,S)$ be a Coxeter system, let $\varphi$ be a weight function on $S$ and let ${\mathrm{Cact}}\_W$ denote the associated {\it cactus group}. Following an idea of I. Losev, we construct an action of ${\mathrm{Cact}}\_W \times {\mathrm{Cact}}\_W$ on ... More
Semicontinuity properties of Kazhdan-Lusztig cellsAug 26 2008May 31 2010Computations in small Coxeter groups or dihedral groups suggest that the partition into Kazhdan-Lusztig cells with unequal parameters should obey to some semicontinuity phenomenon (as the parameters vary). The aim of this paper is to provide a rigorous ... More
On Brane World Cosmological PerturbationsMay 09 2002We discuss the scalar cosmological perturbations in a 3-brane world with a 5D bulk. We first show explicitly how the effective perturbed Einstein's equations on the brane (involving the Weyl fluid) are encoded into Mukohyama's master equation. We give ... More
From light to hyper-heavy molecules and neutron-star crusts in a dynamical mean-field approachNov 11 2012The richness of phenomena occurring in heavy-ion collisions calls for microscopic approaches where the motion of each nucleon is treated quantum mechanically. The most popular microscopic approach for low-energy collisions between atomic nuclei is the ... More
Topologie sur l'ensemble des parties positives d'un réseauAug 26 2008We define a notion of {\it positive part} of a lattice $\Lambda$ and we endow the set of such positive parts with a topology. We then study some properties of this topology, by comparing it with the one of $V^*/\RM_{> 0}$, where $V^*$ is the dual vector ... More
Unsharp pointer observables and the structure of decoherenceFeb 05 2008The theory of decoherence attempts to explain the emergent classical behaviour of a quantum system interacting with its quantum environment. In order to formalize this mechanism we introduce the idea that the information preserved in an open quantum evolution ... More
Branching rules, Kostka-Foulkes polynomials and $q$-multiplicities in tensor product for the root systems $B\_{n},C\_{n}$ and $D\_{n}$Dec 31 2004Jan 17 2005The Kostka-Foulkes polynomials $K$ related to a root system $\phi $ can be defined as alternated sums running over the Weyl group associated to $\phi .$ By restricting these sums over the elements of the symmetric group when $% \phi $ is of type $B,C$ ... More
Sur les caractères des groupes réductifs finis : applications aux groupes spéciaux linéaires et unitairesApr 05 2005In the first chapters, this paper contains a survey on the theory of ordinary characters of finite reductive groups with non-connected centre. The last chapters are devoted to the proof of Lusztig's conjecture on characteristic functions of character ... More
Effects of fermionic singlet neutrinos on high- and low-energy observablesNov 22 2013In this doctoral thesis, we study both low- and high-energy observables related to massive neutrinos. Neutrino oscillations have provided indisputable evidence in favour of non-zero neutrino masses and mixings. However, the original formulation of the ... More
Conditions for the approximate correction of algebrasJul 24 2009We study the approximate correctability of general algebras of observables, which represent hybrid quantum-classical information. This includes approximate quantum error correcting codes and subsystems codes. We show that the main result of arXiv:quant-ph/0605009 ... More
Dualité sur un corps local de caractéristique positive à corps résiduel algébriquement closNov 04 2014Let K be a complete discretely valued field with residue field k of characteristic p>0. There is a duality theory for cohomology with coefficients in commutative finite K-group schemes in the following cases : char(K)=0 and k finite (Tate), char(K)=p ... More
Square functions for Ritt operators on noncommutative $L^p$-spacesJul 18 2011Feb 18 2012For any Ritt operator $T$ acting on a noncommutative $L^p$-space, we define the notion of \textit{completely} bounded functional calculus $H^\infty(B_\gamma)$ where $B_\gamma$ is a Stolz domain. Moreover, we introduce the `column square functions' $\norm{x}_{T,c,\alpha}=\Bnorm{\Big(\sum_{k=1}^{+\infty}k^{2\alpha-1}|T^{k-1}(I-T)^{\alpha}(x)|^2\Big)^{1/2}}_{L^p(M)}$ ... More
Geometrical approach to the proton spin decompositionMay 29 2012Jan 29 2013We discuss in detail and from the geometrical point of view the issues of gauge invariance and Lorentz covariance raised by the approach proposed recently by Chen et al. to the proton spin decomposition. We show that the gauge invariance of this approach ... More
Electromagnetic Properties for Arbitrary Spin Particles: Part 1 $-$ Electromagnetic Current and Multipole DecompositionJan 27 2009In a set of two papers, we propose to study an old-standing problem, namely the electromagnetic interaction for particles of arbitrary spin. Based on the assumption that light-cone helicity at tree level and $Q^2=0$ should be conserved non-trivially by ... More
Improvement of the Theta+ width estimation method on the Light ConeMar 28 2006Jun 29 2006Recently, Diakonov and Petrov have suggested a formalism in the Relativistic Mean Field Approximation allowing one to derive the 3-, 5-, 7-,... quark wavefunctions for the octet, decuplet and antidecuplet. They have used this formalism and many strong ... More
Baryon vector and axial content up to the 7Q componentAug 23 2007Aug 02 2008We have used the light-cone formulation of Chiral-Quark Soliton Model to investigate the vector and axial content of octet, decuplet and the hypothetical antidecuplet in the flavor SU(3) symmetry limit. We have extended previous works by computing the ... More
A polynomial-time algorithm for planar multicuts with few source-sink pairsJun 18 2012Given an edge-weighted undirected graph and a list of k source-sink pairs of vertices, the well-known minimum multicut problem consists in selecting a minimum-weight set of edges whose removal leaves no path between every source and its corresponding ... More
A note on the Grothendieck ring of the symmetric groupNov 02 2005Nov 30 2005Let $p$ be a prime number and let $n$ be a non-zero natural number. We compute the descending Loewy series of the algebra $R\_n/pR\_n$, where $R\_n$ denotes the ring of virtual ordinary characters of the symmetric group $S\_n$.
Deep learning and the renormalization groupJan 14 2013Mar 13 2013Renormalization group (RG) methods, which model the way in which the effective behavior of a system depends on the scale at which it is observed, are key to modern condensed-matter theory and particle physics. We compare the ideas behind the RG on the ... More
Nuclear Quantum Many-Body Dynamics: From Collective Vibrations to Heavy-Ion CollisionsSep 15 2012Nov 08 2012A summary of recent researches on nuclear dynamics with realistic microscopic quantum approaches is presented. The Balian-V\'en\'eroni variational principle is used to derive the time-dependent Hartree-Fock (TDHF) equation describing the dynamics at the ... More
Unconditionality, Fourier multipliers and Schur multipliersNov 07 2011Apr 02 2012Let $G$ be an infinite locally compact abelian group. If $X$ is Banach space, we show that if every bounded Fourier multiplier $T$ on $L^2(G)$ has the property that $T\ot Id_X$ is bounded on $L^2(G,X)$ then the Banach space $X$ is isomorphic to a Hilbert ... More
Coarse-grained distinguishability of field interactionsSep 10 2015Jun 06 2016Information-theoretical quantities such as statistical distinguishability typically result from optimisations over all conceivable observables. Physical theories, however, are not generally considered valid for all mathematically allowed measurements. ... More
Quasi-isolated elements in reductive groupsFeb 17 2004A semisimple element $s$ of a connected reductive group $G$ is said {\it quasi-isolated} (respectively {\it isolated}) if $C_G(s)$ (respectively $C_G^0(s)$) is not contained in a Levi subgroup of a proper parabolic subgroup of $G$. We study properties ... More
Gauge symmetry and background independence: Should the proton spin decomposition be path independent?Jun 03 2013Dec 31 2013Exploring the similarities between the Chen \emph{et al.} approach, where physical and gauge degrees of freedom of the gauge potential are explicitly separated, and the background field method, we provide an alternative point of view to the proton spin ... More
The light-front energy-momentum tensorOct 02 2015We present the first complete parametrization for the matrix elements of the generic light-front gauge-invariant energy-momentum tensor, derive the expressions giving separately the spin and orbital angular momentum of quarks and gluons as probed in high-energy ... More
Spin structure of the nucleon on the light frontSep 22 2014We briefly review the spin structure of the nucleon and show that it is best thought in the light-front formulation. We discuss in particular the longitudinal and transverse spin sum rules, the proper definition of canonical orbital angular momentum and ... More
Quark spin-orbit correlationsSep 16 2014The proton spin puzzle issue focused the attention on the parton spin and orbital angular momentum contributions to the proton spin. However, a complete characterization of the proton spin structure requires also the knowledge of the parton spin-orbit ... More
Automorphisms of Coxeter groups and Lusztig's conjectures for Hecke algebras with unequal parametersMay 28 2008Aug 31 2009Let $(W,S)$ be a Coxeter system, let $G$ be a finite solvable group of automorphisms of $(W,S)$ and let $\varphi$ be a weight function which is invariant under $G$. Let $\varphi_G$ denote the weight function on $W^G$ obtained by restriction from $\varphi$. ... More
The light-front gauge-invariant energy-momentum tensorFeb 24 2015We provide for the first time a complete parametrization for the matrix elements of the generic asymmetric, non-local and gauge-invariant canonical energy-momentum tensor, generalizing therefore former works on the symmetric, local and gauge-invariant ... More
The bead model and limit behaviors of dimer modelsJul 06 2006Feb 23 2011In this paper, we study the bead model: beads are threaded on a set of wires on the plane represented by parallel straight lines. We add the constraint that between two consecutive beads on a wire; there must be exactly one bead on each neighboring wire. ... More
Plünnecke and Kneser type theorems for dimension estimatesSep 01 2011Aug 26 2013Given a division ring K containing the field k in its center and A,B two finite subsets of K\{0}, we give some analogues of Pl\"unnecke and Kneser theorems for the dimension of the k-linear span of the Minkowski product AB in terms of the dimensions of ... More
Superdiffusion of energy in Hamiltonian systems perturbed by a conservative noiseAug 20 2013Oct 05 2013We review some recent results on the anomalous diffusion of energy in systems of 1D coupled oscillators and we revisit the role of momentum conservation.
Coulomb explosion imaging of concurrent CH$_{2}$BrI photodissociation dynamicsOct 06 2017The dynamics following laser-induced molecular photodissociation of gas-phase CH$_{2}$BrI at 271.6 nm were investigated by time-resolved Coulomb explosion imaging using intense near-IR femtosecond laser pulses. The observed delay-dependent photofragment ... More
Microscopic description of heavy ion collisions around the barrierApr 17 2009A microscopic mean-field description of heavy ion collisions is performed in the framework of the time dependent Hartree-Fock theory using a Skyrme energy density functional. A good agreement with experiments is obtained on the position of the fusion ... More
Actinide collisions for QED and superheavy elements with the time-dependent Hartree-Fock theory and the Balian-Vénéroni variational principleAug 11 2011Collisions of actinide nuclei form, during very short times of few zs ($10^{-21}$ s), the heaviest ensembles of interacting nucleons available on Earth. Such collisions are used to produce super-strong electric fields by the huge number of interacting ... More
Bayesian Pursuit AlgorithmsJan 29 2014This paper addresses the sparse representation (SR) problem within a general Bayesian framework. We show that the Lagrangian formulation of the standard SR problem, i.e., $\mathbf{x}^\star=\arg\min_\mathbf{x} \lbrace \| \mathbf{y}-\mathbf{D}\mathbf{x} ... More
Finite BMS transformationsJan 15 2016The action of finite BMS and Weyl transformations on the gravitational data at null infinity is worked out in three and four dimensions in the case of an arbitrary conformal factor for the boundary metric induced on Scri.
A Stochastic Model for Car-Sharing SystemsApr 15 2015Vehicle-sharing systems are becoming important for urban transportation. In these systems, users arrive at a station, pick up a vehicle, use it for a while and then return it to another station of their choice. Depending on the type of system, there might ... More
Comments on holographic current algebras and asymptotically flat four dimensional spacetimes at null infinitySep 03 2013Oct 21 2013We follow the spirit of a recent proposal to show that previous computations for asymptotically flat spacetimes in four dimensions at null infinity can be re-interpreted in terms of a well-defined holographic current algebra for the time component of ... More
Time-Depentent Hartree-Fock description of heavy ions fusionNov 06 2007A microscopic mean-field description of heavy ions fusion is performed in the framework of the Time-Dependent Hartree-Fock (TDHF) theory using a Skyrme interaction with the SLy4d parametrization. A good agreement with experiments is obtained on the position ... More
Generalized Swiss-cheese cosmologies: Mass scalesOct 01 2009Jan 11 2010We generalize the Swiss-cheese cosmologies so as to include nonzero linear momenta of the associated boundary surfaces. The evolution of mass scales in these generalized cosmologies is studied for a variety of models for the background without having ... More
Algorithms for nonnegative matrix factorization with the beta-divergenceOct 08 2010Mar 08 2011This paper describes algorithms for nonnegative matrix factorization (NMF) with the beta-divergence (beta-NMF). The beta-divergence is a family of cost functions parametrized by a single shape parameter beta that takes the Euclidean distance, the Kullback-Leibler ... More
Algebraic approach to quantum theory: a finite-dimensional guideMay 12 2015Nov 16 2015This document is meant as a pedagogical introduction to the modern language used to talk about quantum theories, especially in the field of quantum information. It assumes that the reader has taken a first traditional course on quantum mechanics, and ... More
Reduced-Order Modeling Of Hidden DynamicsOct 08 2015The objective of this paper is to investigate how noisy and incomplete observations can be integrated in the process of building a reduced-order model. This problematic arises in many scientific domains where there exists a need for accurate low-order ... More
Coxeter orbits and modular representationsNov 30 2005Mar 15 2006We study the modular representations of finite groups of Lie type arising in the cohomology of certain quotients of Deligne-Lusztig varieties associated with Coxeter elements. These quotients are related to Gelfand-Graev representations and we present ... More
Generalized Transverse-Momentum Dependent Parton Distributions in Light-Cone Quark ModelsSep 28 2010We discuss the general formalism for the calculation in light-cone quark models of the fully unintegrated, off-diagonal quark-quark correlator of the nucleon. The corresponding distributions in impact parameter space are the Wigner or phase-space distributions. ... More
Heavy neutrino impact on the triple Higgs couplingMar 02 2016Nov 28 2016We present the first calculation of the one-loop corrections to the triple Higgs coupling in the framework of a simplified 3+1 Dirac neutrino model, that is three light neutrinos plus one heavy neutrino embedded in the Standard Model (SM). The triple ... More
Online Inference for Relation Extraction with a Reduced Feature SetApr 18 2015Access to web-scale corpora is gradually bringing robust automatic knowledge base creation and extension within reach. To exploit these large unannotated---and extremely difficult to annotate---corpora, unsupervised machine learning methods are required. ... More
Anticollinear magnetic order induced by impurities in the frustrated Heisenberg model of pnictidesJun 30 2012We present Monte Carlo simulations for a classical antiferromagnetic Heisenberg model with both nearest ($J_1$) and next-nearest ($J_2$) exchange couplings on the square lattice in the presence of non-magnetic impurities. We show that the order-by-disorder ... More
Delta Hedging in Financial Engineering: Towards a Model-Free ApproachMay 03 2010Delta hedging, which plays a crucial r\^ole in modern financial engineering, is a tracking control design for a "risk-free" management. We utilize the existence of trends in financial time series (Fliess M., Join C.: A mathematical proof of the existence ... More
Model-free controlMay 30 2013Nov 20 2013"Model-free control" and the corresponding "intelligent" PID controllers (iPIDs), which already had many successful concrete applications, are presented here for the first time in an unified manner, where the new advances are taken into account. The basics ... More
Regularity theory for the spatially homogeneous Boltzmann equation with cut-offJul 21 2006We develop the regularity theory of the spatially homogeneous Boltzmann equation with cut-off and hard potentials (for instance, hard spheres), by (i) revisiting the Lp-theory to obtain constructive bounds, (ii) establishing propagation of smoothness ... More
Supertranslations call for superrotationsFeb 22 2011Aug 21 2012We review recent results on symmetries of asymptotically flat spacetimes at null infinity. In higher dimensions, the symmetry algebra realizes the Poincar\'e algebra. In three and four dimensions, besides the infinitesimal supertranslations that have ... More
PT-Scotch: A tool for efficient parallel graph orderingJul 08 2009The parallel ordering of large graphs is a difficult problem, because on the one hand minimum degree algorithms do not parallelize well, and on the other hand the obtainment of high quality orderings with the nested dissection algorithm requires efficient ... More
Hecke algebras with unequal parameters and Vogan's left cell invariantsFeb 05 2015In 1979, Vogan introduced a generalised $\\tau$ -invariant for characterising primitive ideals in enveloping algebras. Via a known dictionary this translates to an invariant of left cells in the sense of Kazhdan and Lusztig. Although it is not a complete ... More
Some complete intersection symplectic quotients in positive characteristic: invariants of a vector and a covectorJun 24 2010Apr 04 2011Given a linear action of a group $G$ on a $K$-vector space $V$, we consider the invariant ring $K[V \oplus V^*]^G$, where $V^*$ is the dual space. We are particularly interested in the case where $V =\gfq^n$ and $G$ is the group $U_n$ of all upper unipotent ... More