Results for "Thierry Grandou"

total 1981took 0.12s
Effective locality and chiral symmetry breaking in $QCD$May 14 2019A few years ago the use of standard functional manipulations was demonstrated to imply an unexpected property satisfied by the fermionic Green's functions of QCD, and called \textit{effective locality}. This feature of QCD is non-perturbative as it results ... More
Angular intricacies in hot gauge field theoriesApr 02 2003It is argued that in hot gauge field theories, "Hard Thermal Loops" leading order calculations call for a definite sequence of angular averages and discontinuity (or Imaginary part prescription) operations, and run otherwise into incorrect results. The ... More
Proof of a mass singularity free property in high temperature QCDJan 22 2003It is shown that three series of diagrams entering the calculation of some hot $QCD$ process, are mass (or collinear) singularity free, indeed. This generalizes a result which was recently established up to the third non trivial order of (thermal) Perturbation ... More
On the Light Cone Singularity of the Thermal Effective ExpansionMay 06 1996We consider a scalar massless quantum field model, at finite temperature $T$, both renormalizable and asymptotically free. Focussing on the singular structure of the effective perturbation theory about the light cone, several new insights are put forth, ... More
Thermal ground state and nonthermal probesMar 18 2015Aug 24 2015The Euclidean formulation of SU(2) Yang-Mills thermodynamics admits periodic, (anti)selfdual solutions to the fundamental, classical equation of motion which possess one unit of topological charge: (anti)calorons. A spatial coarse graining over the central ... More
Spacetime deployments parametrized by gravitational and electromagnetic fieldsApr 23 2004Oct 07 2004On the basis of a "Punctual" Equivalence Principle of the general relativity context, we consider spacetimes with measurements of conformally invariant physical properties. Then, applying the Pfaff theory for PDE to a particular conformally equivariant ... More
Time 'betwins'Jun 15 2004Jun 16 2004Discussions on the Langevin Twins 'paradox' are most often based on a "triangular" diagram which outlines the twins spacetime travels. It won't be our way, avoiding what we think to be a problem at the basis of numerous controversies. Our approach relies ... More
Chiral Symmetry Breaking out of QCD Effective LocalityOct 11 2018The QCD non-perturbative property of Effective Locality whose essential meaning has been disclosed recently, is here questioned about the chiral symmetry breaking phenomenon, one of the two major issues of the non-perturbative phase of QCD. As a first ... More
On the non-perturbative realization of QCD gauge-invarianceJun 07 2017A few years ago the use of standard functional manipulations was demonstrated to imply an unexpected property satisfied by the fermionic Green's functions of QCD: effective locality. This feature of QCD is non-perturbative as it results from a full integration ... More
Massive loops in thermal SU(2) Yang-Mills theory: Radiative corrections to the pressure beyond two loopsMar 21 2017We device an efficient book-keeping of excluded energy-sign and scattering-channel combinations for the loop four-momenta associated with massive quasi-particles, circulating in (connected) bubble diagrams subject to vertex constraints inherited from ... More
On Quantum Fields at High TemperatureJan 18 2019Jan 21 2019Revisiting the fast fermion damping rate calculation in a thermalized QED and/or QCD plasma at 4-loop order, focus is put on a peculiar perturbative structure which has no equivalent at zero-temperature. Not surprisingly and in agreement with previous ... More
Twin Paradox and CausalityApr 20 2007After pointing out the historical avatar at the origin of a would be twin or clock paradox, we argue that, at least on a local scale, the (re-qualified) paradox is but a necessary consequence of the sole principle of causality.
Comparison of Non-Perturbative, Gauge-Invariant, Realistic QCD with ISR Elastic pp Scattering DataNov 08 2016Using previously-described, functional techniques for exact solutions to QCD processes, a simplified version of the amplitudes provides high-quality fits to the ISR data. Qualitative generalizations to initial LHC data are suggested, and are presently ... More
Comparison of Gluon Bundle based QCD Curves with ISR Elastic pp Scattering DataNov 08 2016Nov 30 2016Using previously described, functional techniques for solutions to QCD processes, a simplified version of the amplitudes provides fits to the ISR data.
Comparison of Gluon Bundle based QCD Curves with ISR Elastic pp Scattering DataNov 08 2016May 16 2017Using previously described functional techniques for exact, non-perturbative, gauge-invariant renormalized QCD processes, a simplified version of the amplitudes - in which forms akin to Pomerons naturally appear - provides fits to ISR Elastic pp scattering ... More
On the Casimir operator dependences of QCD amplitudesFeb 28 2014Mar 25 2014In eikonal and quenched approximations at least, it is argued that the strong coupling fermionic QCD amplitudes obtained with the help of the newly discovered effective locality property, depart from a dependence on the sole $SU_c(3)$ quadratic Casimir ... More
Puzzling aspects of hot quantum fieldsSep 29 2000Over the past decade, Finite Temperature Quantum Field Theories have benefitted from impressive developments, while an increasing number of intriguing points were made. Some of them are presented here, recent and older, in a non exhaustive list.
Dealing with Metonymic Readings of Named EntitiesJul 11 2006The aim of this paper is to propose a method for tagging named entities (NE), using natural language processing techniques. Beyond their literal meaning, named entities are frequently subject to metonymy. We show the limits of current NE type hierarchies ... More
Non integrability of a self-gravitating Riemann liquid ellipsoidFeb 08 2012We prove that the motion of a triaxial Riemann ellipsoid of homogeneous liquid without angular momentum does not possess an additional first integral which is meromorphic in position, impulsions, and the elliptic functions which appear in the potential, ... More
Are magnetic OB stars more prone to mixing? Still an unsettled issueJan 11 2012We review our knowledge of the mixing properties of magnetic OB stars and discuss whether the observational data presently available support, as predicted by some theoretical models, the idea that magnetic phenomena favour the transport of the chemical ... More
Non integrability of the n body problem with non zero angular momentumDec 08 2011We prove an integrability criterion and a partial integrability criterion for homogeneous potentials of degree -1 which are invariant by rotation. We then apply it to the proof of the meromorphic non-integrability of the n body problem with Newtonian ... More
Integrability conditions at order 2 for homogeneous potentials of degree -1Sep 26 2011We prove a meromorphic integrability condition at order 2 near a homothetic orbit for a meromorphic homogeneous potential of degree -1, which extend the Morales Ramis conditions of order 1. Conversely, we prove that if this criterion is satisfied, then ... More
Context Tree Estimation in Variable Length Hidden Markov ModelsSep 02 2011Sep 14 2011We address the issue of context tree estimation in variable length hidden Markov models. We propose an estimator of the context tree of the hidden Markov process which needs no prior upper bound on the depth of the context tree. We prove that the estimator ... More
Interactions in Quantum FluidsJul 07 2010In these notes I review the basic concepts of the effects of interactions on quantum particles. I focuss here mostly on the case of fermions, but several aspects of interacting bosons are mentioned as well. These notes have been voluntarily kept at an ... More
Quantum Phase Transitions in quasi-one dimensional systemsJul 07 2010I review in this chapter several classes of quantum phase transitions that occur in quasi-one dimensional systems. I start by examining the simple case of coupled spin chains and ladders, then move to the case of bosons, and finally deal with the more ... More
Physical limit to concentration sensing amid spurious ligandsApr 27 2015Jul 22 2015To adapt their behaviour in changing environments, cells sense concentrations by binding external ligands to their receptors. However, incorrect ligands may bind nonspecifically to receptors, and when their concentration is large, this binding activity ... More
Spectroscopic constraints for low-mass asteroseismic targetsMar 20 2014A full exploitation of the observations provided by the CoRoT and Kepler missions depends on our ability to complement these data with accurate effective temperatures and chemical abundances. We review in this contribution the major efforts that have ... More
A Duality Approach to the Genealogies of Discrete Non-Neutral Wright-Fisher ModelsNov 06 2008Discrete ancestral problems arising in population genetics are investigated. In the neutral case, the duality concept has proved of particular interest in the understanding of backward in time ancestral process from the forward in time branching population ... More
A new proof of the analyticity of the electronic density of moleculesApr 01 2009Jun 30 2010We give a new, short proof of the regularity away from the nuclei of the electronic density of a molecule obtained in [1,2]. The new argument is based on the regularity properties of the Coulomb interactions underlined in [3,4] and on well-known elliptic ... More
Poincaré et les quantaJan 21 2009We present some reflections concerning two papers by H. Poincar\'e concerning the theory of quanta.
Antares/Virgo Coincidences : a feasibility studyJul 16 2008Sources of gravitational waves (GW) and emitters of high energy (HE) neutrinos both involve compact objects and matter moving at relativistic speeds. Coincidences between Virgo and Antares would give a unique insight on the physics of the most powerful ... More
A single step protein assay that is both detergent and reducer compatible: The cydex blue assayOct 24 2016Determination of protein concentration in often an absolute pre-requisite in preparing samples for biochemical and proteomic analyses. However, current protein assay methods are not compatible with both reducers and detergents, which are however present ... More
Semilinear automorphisms or reductive algebraic groupsJan 16 2019Let $ G $ be a connected reductive algebraic group over a field $ k $. We study the group of semilinear automorphisms Aut($ G\to $Spec $k$) consisting of algebraic automorphisms of $ G $ over automorphisms of $ k $. We focus on the exact sequence $ 1\to ... More
Integrable homogeneous potentials of degree $-1$ in the plane with small eigenvaluesOct 27 2011Apr 18 2015We give a complete classification of meromorphically integrable homogeneous potentials $V$ of degree $-1$ which are real analytic on $\mathbb{R}^2\setminus \{0\}$. In the more general case when $V$ is only meromorphic on an open set of an algebraic variety, ... More
Les extensions intrinseques les plus simples des ensembles R et N pour une nouvelle Analyse Non standardJun 30 2012The main results of this paper are the formal constructions, both rigorous and intuitive of the "Aleph" intrinsic extension of the set of non negative integers N and the "Omega" smallest strict over-field of R which is totally ordered and complete. The ... More
Prefixes of minimal factorisations of a cycleMay 29 2011We give a bijective proof of the fact that the number of k-prefixes of minimal factorisations of the n-cycle (1...n) as a product of n-1 transpositions is n^{k-1}\binom{n}{k+1}. Rather than a bijection, we construct a surjection with fibres of constant ... More
Topology of definable Hausdorff limitsJul 28 2003Mar 23 2004Let $A\sub \R^{n+r}$ be a set definable in an o-minimal expansion $\S$ of the real field, $A' \sub \R^r$ be its projection, and assume that the non-empty fibers $A_a \sub \R^n$ are compact for all $a \in A'$ and uniformly bounded, {\em i.e.} all fibers ... More
Revisitation of the original hot QCD collinear singularity problemApr 27 2010Nov 16 2010The long standing issue known as the hot QCD collinear singularity problem has been proven to rely on an incorrect sequence of two mathematical operations. Here, the original derivation of this problem is entirely revisited within the correct sequence, ... More
On a fate of hot quantum field theoriesSep 29 2000It is argued that for hot quantum fields, the necessary effective perturbation theories may be based on a resummation procedure which, contrarily to the zero temperature case, differs substantially from the one ordinarily in use. Important differences ... More
Thermal Field Theory and Infinite StatisticsJun 17 1992Oct 28 1992We construct a quantum thermal field theory for scalar particles in the case of infinite statistics. The extension is provided by working out the Fock space realization of a "quantum algebra", and by identifying the hamiltonian as the energy operator. ... More
A deformation formula for the heat kernelFeb 07 2013Let us consider a time-dependent differential operator quadratic with respect to the phase variables. Let us consider a multiplication operator defined with the help of a "small" matrix-valued function. Under suitable conditions, we give an "explicit" ... More
Borel summation of the semi-classical expansion of the partition function associated to the Schrödinger equationMay 16 2013We prove that the partition function associated to a perturbation of the semi-classical harmonic oscillator is the Borel sum of its semi-classical expansion.
DisPerSE: robust structure identification in 2D and 3DFeb 25 2013We present the DIScrete PERsistent Structures Extractor (DisPerSE), an open source software for the automatic and robust identification of structures in 2D and 3D noisy data sets. The software is designed to identify all sorts of topological structures, ... More
Digital Mathematics Libraries: The Good, the Bad, the UglyJan 22 2010The idea of a World digital mathematics library (DML) has been around since the turn of the 21th century. We feel that it is time to make it a reality, starting in a modest way from successful bricks that have already been built, but with an ambitious ... More
Keynotes on membrane proteomicsJul 07 2008This review article deals with the specificities of the proteomics analysis of membrane proteins.
Coincidences between Gravitational Wave Interferometers and High Energy Neutrino TelescopesJul 16 2008Sources of gravitational waves (GW) and emitters of high energy (HE) neutrinos both involve compact objects and matter moving at relativistic speeds. GW emission requires a departure from spherical symmetry, which is the case if clumps of matter are accreted ... More
When 2D is not enough, go for an extra dimensionNov 15 2013The use of an extra SDS separation in a different buffer system provide a technique for deconvoluting 2D gel spots made of several proteins (Colignon et al. Proteomics, 2013, 13, 2077-2082). This technique keeps the quantitative analysis of the protein ... More
Some experimental tests of Tomonaga-Luttinger liquidsAug 13 2013The Tomonaga-Luttinger-Liquid (TLL) has been the cornerstone of our understanding of the properties of one dimensional systems. This universal set of properties plays in one dimension, the same role than Fermi liquid plays for the higher dimensional metals. ... More
On the mathematical treatment of the Born-Oppenheimer approximationMar 23 2013Apr 24 2014Motivated by a paper by B.T. Sutcliffe and R.G. Woolley, we present the main ideas used by mathematicians to show the accuracy of the Born-Oppenheimer approximation for molecules. Based on mathematical works on this approximation for molecular bound states, ... More
How to use 2D gel electrophoresis in plant proteomicsDec 04 2013Two-dimensional electrophoresis has nurtured the birth of proteomics. It is however no longer the exclusive setup used in proteomics, with the development of shotgun proteomics techniques that appear more fancy and fashionable nowadays.Nevertheless, 2D ... More
Deformations of Fuchsian AdS representations are Quasi-FuchsianJan 18 2013May 29 2013Let $\Gamma$ be a finitely generated group, and let $\op{Rep}(\Gamma, \SO(2,n))$ be the moduli space of representations of $\Gamma$ into $\SO(2,n)$ ($n \geq 2$). An element $\rho: \Gamma \to \SO(2,n)$ of $\op{Rep}(\Gamma, \SO(2,n))$ is \textit{quasi-Fuchsian} ... More
Silver Staining of 2D Electrophoresis GelsJun 14 2012Silver staining is used to detect proteins after electrophoretic separation on polyacrylamide gels. It -combines excellent sensitivity (in the low nanogram range) with the use of very simple and cheap equipment and chemicals. For its use in proteomics, ... More
The Whereabouts of 2D Gels in Quantitative ProteomicsJun 14 2012Two-dimensional gel electrophoresis has been instrumental in the development of proteomics. Although it is no longer the exclusive scheme used for proteomics, its unique features make it a still highly valuable tool, especially when multiple quantitative ... More
Chabauty limits of algebraic groups acting on treesOct 26 2016Given a locally finite leafless tree $ T $, various algebraic groups over local fields might appear as closed subgroups of $ \text{Aut} (T)$. We show that the set of closed cocompact subgroups of $ \text{Aut} (T)$ that are isomorphic to a quasi-split ... More
A generalized closure concept based on neighborhood-equivalence and preserving graph HamiltonicityAug 28 2013A graph is Hamiltonian if it contains a cycle which goes through all vertices exactly once. Determining if a graph is Hamiltonian is known as a NP-complete problem and no satisfactory characterization for these graphs has been found. In 1976 Bondy and ... More
Integrability of the one dimensional Schroedinger equationSep 14 2016We present a definition of integrability for the one dimensional Schroedinger equation, which encompasses all known integrable systems, i.e. systems for which the spectrum can be explicitly computed. For this, we introduce the class of rigid functions, ... More
Combinatorics of The Interrupted PeriodMay 01 2014Nov 14 2018This article is about discrete periodicities and their combinatorial structure. It describes the unique structure caused by the alteration of a pattern in a repetition. That alteration of a pattern could be "heard" as the disturbance that one can hear ... More
Schur-Weyl duality and the heat kernel measure on the unitary groupMar 23 2007Jan 15 2008We establish a convergent power series expansion for the expectation of a product of traces of powers of a random unitary matrix under the heat kernel measure. These expectations turn out to be the generating series of certain paths in the Cayley graph ... More
Fractal trees for irreducible automorphisms of free groupsOct 16 2009The self-similar structure of the attracting subshift of a primitive substitution is carried over to the limit set of the repelling tree in the boundary of Outer Space of the corresponding irreducible outer automorphism of a free group. Thus, this repelling ... More
Integrability and non integrability of some n body problemsSep 28 2015We prove the non integrability of the colinear $3$ and $4$ body problem, for any masses positive masses. To deal with resistant cases, we present strong integrability criterions for $3$ dimensional homogeneous potentials of degree $-1$, and prove that ... More
A homological condition for a dynamical and illuminatory classification of torus branched coveringsMar 14 2006We prove that, for translation surfaces whose homology is generated by the periodic orbits, the notions of - finite blocking property - pure periodicity - torus branched covering are equivalent. In particular, we prove this equivalence for convex surfaces ... More
Submanifolds and Quotient Manifolds in Noncommutative GeometryJul 26 1995We define and study noncommutative generalizations of submanifolds and quotient manifolds, for the derivation-based differential calculus introduced by M.~Dubois-Violette and P.~Michor. We give examples to illustrate these definitions.
Quasi-Fuchsian AdS representations are AnosovOct 04 2007In a recent paper, Q. M\'erigot proved that representations in SO(2,n) of uniform lattices of SO(1,n) which are Anosov in the sense of Labourie are quasi-Fuchsian, i.e. are faithfull, discrete, and preserve an acausal subset in the boundary of anti-de ... More
Globally Hyperbolic Flat SpacetimesFeb 16 2004We consider (flat) Cauchy-complete GH spacetimes, i.e., globally hyperbolic flat lorentzian manifolds admitting some Cauchy hypersurface on which the ambient lorentzian metric restricts as a complete riemannian metric. We define a family of such spacetimes ... More
Paleoproteomics explained to youngsters: how did the wedding of two-dimensional electrophoresis and protein sequencing spark proteomics on: Let there be lightAug 06 2014Taking the opportunity of the 20th anniversary of the word "proteomics", this young adult age is a good time to remember how proteomics came from enormous progress in protein separation and protein microanalysis techniques, and from the conjugation of ... More
Combinatorics of The Interrupted PeriodMay 01 2014May 05 2014This article is about discrete periodicities and their combinatorial structure. It describes the unique structure caused by the alteration of a pattern in a repetition. That alteration of a pattern could be "heard" as the disturbance that one can hear ... More
Introduction to Risk Parity and BudgetingMar 07 2014Although portfolio management didn't change much during the 40 years after the seminal works of Markowitz and Sharpe, the development of risk budgeting techniques marked an important milestone in the deepening of the relationship between risk and asset ... More
Variations on a theme: Changes to electrophoretic separations that can make a differenceMay 06 2010Electrophoretic separations of proteins are widely used in proteomic analyses, and rely heavily on SDS electrophoresis. This mode of separation is almost exclusively used when a single dimension separation is performed, and generally represents the second ... More
Gamma-rays from star-forming regions: from SNOBs to dark acceleratorsSep 01 2009Observational gamma-ray astronomy was born some forty years ago, when small detectors were flown in satellites, following a decade of theoretical predictions of its potential to discover the origin of cosmic rays via the pi-zero decay mechanism. The seventies ... More
Solubilization of Proteins in 2DE: An OutlineApr 22 2009Protein solubilization for two-dimensional electrophoresis (2DE) has to break molecular interactions to separate the biological contents of the material of interest into isolated and intact polypeptides. This must be carried out in conditions compatible ... More
Detergents and chaotropes for protein solubilization before two-dimensional electrophoresisApr 04 2009Because of the outstanding ability of two-dimensional electrophoresis to separate complex mixtures of intact proteins, it would be advantageous to apply it to all types of proteins, including hydrophobic and membrane proteins. Unfortunately, poor solubility ... More
Semiclassical analysis and sensitivity to initial conditionsJan 20 2009We present several recent results concerning the transition between quantum and classical mechanics, in the situation where the underlying dynamical system has an hyperbolic behaviour. The special role of invariant manifolds will be emphasized, and the ... More
Measuring the eccentricity of the Earth orbit with a nail and a piece of plywoodJul 04 2012I describe how to obtain a rather good experimental determination of the eccentricity of the Earth orbit, as well as the obliquity of the Earth rotation axis, by measuring, over the course of a year, the elevation of the Sun as a function of time during ... More
Semiclassical approximation and noncommutative geometryAug 28 2011Mar 19 2012We consider the long time semiclassical evolution for the linear Schr\"odinger equation. We show that, in the case of chaotic underlying classical dynamics and for times up to $\hbar^{-2+\epsilon},\ \epsilon>0$, the symbol of a propagated observable by ... More
The complexity of tangent wordsAug 18 2011In a previous paper, we described the set of words that appear in the coding of smooth (resp. analytic) curves at arbitrary small scale. The aim of this paper is to compute the complexity of those languages.
Gauge theories in noncommutative geometryJan 16 2012In this review we present some of the fundamental mathematical structures which permit to define noncommutative gauge field theories. In particular, we emphasize the theory of noncommutative connections, with the notions of curvatures and gauge transformations. ... More
Indeterminisme Quantique et Impredictibilite ClassiqueNov 25 2010We present in an informal way some recent results concerning a possible overlapping between classical unpredictability and quantum indeterminism.
Mixing in magnetic OB starsOct 20 2010Recent observations have revealed the existence of a population of slowly-rotating, nitrogen-rich B dwarfs that are not predicted by evolutionary models including rotational mixing. However, as theoretical arguments suggest that magnetic processes may ... More
Mixing in two magnetic OB stars discovered by the MiMeS collaborationSep 17 2010Recent observational and theoretical arguments suggest that magnetic OB stars may suffer more mixing than their non magnetic analogs. We present the results of an NLTE abundance study revealing a lack of CN-cycled material at the surface of two magnetic ... More
Some remarks on the complex heat kernel in the scalar potential caseFeb 14 2013In previous works, we used a so-called deformation formula in order to study, in particular, the Borel summability of the heat kernel of some operators. A goal of this paper is to collect miscellaneous remarks related to these works. Here the complex ... More
Borel summation of the small time expansion of the heat kernel. The scalar potential caseJan 31 2013We study the Borel summability of the small time expansion of the heat kernel for the Schr\"odinger operator in several dimensions. On the torus, we prove a Poisson formula.
Dualité de Van den Bergh et Structure de Batalin-Vilkovisky sur les algèbres de Calabi-YauJul 23 2009The abstract notion of Tamarkin-Tsygan calculus with duality gives Batalin- Vilkovisky structures in a general setting. We apply this technique to the case of Van den Bergh duality for algebras to prove that Calabi-Yau algebras are BV-algebras.
Are solar granules the only source of acoustic oscillations ?Aug 27 1998The excitation mechanism of low degree acoustic modes is investigated through the analysis of the stochastic time variations of their energy. The correlation between the energies of two different modes is interpreted as the signature of the occurrence ... More
Chabauty limits of algebraic groups acting on treesOct 26 2016Nov 29 2016Given a locally finite leafless tree $ T $, various algebraic groups over local fields might appear as closed subgroups of $ \text{Aut} (T)$. We show that the set of closed cocompact subgroups of $ \text{Aut} (T)$ that are isomorphic to a quasi-split ... More
Derivation of the Tully-Fisher's law from the Theory of EtherAug 30 2011The astrophysicist S. Mc Gaugh recently published (3) a result raising questions concerning the existence of dark matter and the validity of General Relativity, conclusion of his observations of 47 galaxies. He established the validity of Tully-Fisher's ... More
Bose-like condensation of Lagrangian particles and higher-order statistics in passive scalar turbulent advectionAug 24 2010We establish an hitherto hidden connection between zero modes and instantons in the context of the Kraichanan model for passive scalar turbulent advection, that relies on the hypothesis that the production of strong gradients of the scalar is associated ... More
Rational integrability of trigonometric polynomial potentials on the flat torusFeb 05 2017We consider a lattice $\mathcal{L}\subset \mathbb{R}^n$ and a trigonometric potential $V$ with frequencies $k\in\mathcal{L}$. We then prove a strong integrability condition on $V$, using the support of its Fourrier transform. We then use this condition ... More
Interacting vortex pairs in inviscid and viscous planar flowsDec 07 2012The aim of this contribution is to make a connection between two recent results concerning the dynamics of vortices in incompressible planar flows. The first one is an asymptotic expansion, in the vanishing viscosity limit, of the solution of the two-dimensional ... More
Finite blocking property versus pure periodicityJun 24 2004Mar 07 2008A translation surface S is said to have the finite blocking property if for every pair (O,A) of points in S there exists a finite number of "blocking" points B_1,...,B_n such that every geodesic from O to A meets one of the B_i's. S is said to be purely ... More
Discrete and continuous Yang-Mills measure for non-trivial bundles over compact surfacesJan 06 2005We construct one Yang-Mills measure on a compact surface for each isomorphism class of principal bundles over this surface. For this, we define a new discrete gauge theory which is essentially a covering of the usual one. We prove that the measures correponding ... More
Semilinear automorphisms of reductive algebraic groupsJan 16 2019Mar 01 2019Let $ G $ be a connected reductive algebraic group over a field $ k $. We study the group of semilinear automorphisms Aut($ G\to $Spec $k$) consisting of algebraic automorphisms of $ G $ over automorphisms of $ k $. We focus on the exact sequence $ 1\to ... More
Stability and Interaction of Vortices in Two-Dimensional Viscous FlowsMar 05 2012The aim of these notes is to present in a comprehensive and relatively self-contained way some recent developments in the mathematical analysis of two-dimensional viscous flows. We consider the incompressible Navier-Stokes equations in the whole plane, ... More
Slab percolation for the Ising modelSep 18 2003For the FK representation of the Ising model, we prove that the slab percolation threshold coincides with the critical temperature in any dimension larger or equal to three.
Necessary and sufficient conditions for meromorphic integrability near a curveApr 26 2017Let us consider a vector field $X$ meromorphic on a neighbourhood of an algebraic curve $\bar{\Gamma}\subset \mathbb{P}^n$ such that $\Gamma$ is a particular solution of $X$. The vector field $X$ is $(l,n-l)$ integrable if it there exists $Y_1,\dots,Y_{l-1},X$ ... More
Enhanced dissipation and axisymmetrization of two-dimensional viscous vorticesJul 18 2017This paper is devoted to the stability analysis of the Lamb-Oseen vortex in the regime of high circulation Reynolds numbers. When strongly localized perturbations are applied, it is shown that the vortex relaxes to axisymmetry in a time proportional to ... More
Linguistically Grounded Models of Language ChangeJul 11 2006Questions related to the evolution of language have recently known an impressive increase of interest (Briscoe, 2002). This short paper aims at questioning the scientific status of these models and their relations to attested data. We show that one cannot ... More
Automatic extraction of paraphrastic phrases from medium size corporaSep 28 2005This paper presents a versatile system intended to acquire paraphrastic phrases from a representative corpus. In order to decrease the time spent on the elaboration of resources for NLP system (for example Information Extraction, IE hereafter), we suggest ... More
Recent results in semiclassical approximation with rough potentialsSep 15 2011This is an extended abstract for the conference "Microlocal2011 : Microlocal Methods in Mathematical Physics and Global Analysis Universit\"at T\"ubingen, June 14 - 18, 2011"
Échelles de temps pour l'évolution quantique à petite constante de PlanckJan 21 2009We present some recent results concerning the long time semiclassical approximation .
Mitochondrial proteomics: analysis of a whole mitochondrial extract with two-dimensional electrophoresisJul 08 2008Mitochondria are complex organelles, and their proteomics analysis requires a combination of techniques. The emphasis in this chapter is made first on mitochondria preparation from cultured mammalian cells, then on the separation of the mitochondrial ... More