Results for "Jean-Francois Donati"

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Direct magnetic field detection in the innermost regions of an accretion discNov 24 2005Models predict that magnetic fields play a crucial role in the physics of astrophysical accretion disks and their associated winds and jets. For example, the rotation of the disk twists around the rotation axis the initially vertical magnetic field, which ... More
Coronal Structure of Low-Mass StarsJul 09 2012We investigate the change in stellar magnetic topology across the fully-convective boundary and its effects on coronal properties. We consider both the magnitude of the open flux that influences angular momentum loss in the stellar wind and X-ray emission ... More
Global 3D Simulations of Disc Accretion onto the classical T Tauri Star V2129 OphDec 09 2009Sep 17 2010The magnetic field of the classical T Tauri star V2129 Oph can be modeled approximately by superposing slightly tilted dipole and octupole moments, with polar magnetic field strengths of 0.35kG and 1.2kG respectively (Donati et al. 2007). Here we construct ... More
Magnetic fields on young, moderately rotating Sun-like stars - I: HD~35296 and HD~29615Feb 20 2015Observations of the magnetic fields of young solar-type stars provide a way to investigate the signatures of their magnetic activity and dynamos. Spectropolarimetry enables the study of these stellar magnetic fields and was thus employed at the T\'{e}lescope ... More
The Explicit Formula in simple termsOct 29 1998Nov 22 1998This is a semi-expository paper on the easier aspects of the Explicit Formula for the Riemann Zeta Function. The topics reviewed here include: Weil's criterion for the Riemann Hypothesis and its probabilistic interpretation, various formulations of the ... More
Spectral Analysis of the local Commutator OperatorsDec 01 1998The spectral analysis of the (local) conductor operator H = log(|q|) + log(|p|) was shown in a previous paper to be given by the Explicit Formula. I give here the spectral analysis of the commutator operator K = i[log(|p|),log(|q|)] (which shares with ... More
An adelic causality problem related to abelian L-functionsJan 04 2000Sep 14 2000I associate to a global field K a Lax-Phillips scattering which has the property of causality if and only if the Riemann Hypothesis holds for all the abelian L-functions of K. As a Hilbert space closure problem this provides an adelic variation on a theme ... More
Quaternionic Gamma functions and their logarithmic derivatives as spectral functionsApr 12 1999Nov 10 2000We establish Connes's local trace formula (related to the explicit formulae of number theory) for the quaternions. This is done as an application of a study of the central operator H = log(|x|) + log(|y|) in the context of invariant harmonic analysis. ... More
Diffusion processes with weak constraint through penalization approximationApr 05 2017Apr 19 2017In this paper, we investigate the construction of a diffusion process whose time-marginal densities are constrained to belong to a given set at all time. The construction is obtained from a penalization approximation to the constraint set, acting on the ... More
Lower semicontinuity of quasiconvex bulk energies in SBV and integral representation in dimension reductionDec 07 2006Nov 07 2007A result of Larsen concerning the structure of the approximate gradient of certain sequences of functions with Bounded Variation is used to present a short proof of Ambrosio's lower semicontinuity theorem for quasiconvex bulk energies in $SBV$. It enables ... More
A Floer fundamental groupApr 12 2014Feb 21 2017The main purpose of this paper is to provide a description of the fundamental group of a symplectic manifold in terms of Floer theoretic objects. As an application, we show that when counted with a suitable notion of multiplicity, non degenerate Hamiltonian ... More
Finitude pour les representations lisses de groupes p-adiquesJul 18 2006We study basic properties of the category of smooth representations of a p-adic group G with coefficients in any commutative ring R in which p is invertible. Our main purpose is to prove that Hecke algebras are noetherian whenever R is ; a question left ... More
Random trees and applicationsNov 21 2005We discuss several connections between discrete and continuous random trees. In the discrete setting, we focus on Galton-Watson trees under various conditionings. In particular, we present a simple approach to Aldous' theorem giving the convergence in ... More
The topological structure of scaling limits of large planar mapsJul 22 2006Oct 31 2006We discuss scaling limits of large bipartite planar maps. If p is a fixed integer strictly greater than 1, we consider a random planar map M(n) which is uniformly distributed over the set of all 2p-angulations with n faces. Then, at least along a suitable ... More
An invariance principle for conditioned treesMar 14 2005We consider Galton-Watson trees associated with a critical offspring distribution and conditioned to have exactly $n$ vertices. These trees are embedded in the real line by affecting spatial positions to the vertices, in such a way that the increments ... More
The Explicit Formula and a PropagatorSep 21 1998Nov 22 1998I give a new derivation of the Explicit Formula for the general number field K, which treats all primes in exactly the same way, whether they are discrete or archimedean, and also ramified or not. In another token, I advance a probabilistic interpretation ... More
Mesures limites pour l'equation de Helmholtz dans le cas non captifJul 05 2007Cet article est consacre a l'etude des mesures limites associees a la solution de l'equation de Helmholtz avec un terme source se concentrant en un point. Le potentiel est suppose regulier et l'operateur non-captif. La solution de l'equation de Schrodinger ... More
Field theory on the light-frontNov 02 2010We present a general framework to study relativistic compound systems in a Hamiltonian formalism. This formalism is based on the explicitly covariant formulation of light-front dynamics, with a decomposition of the state vector in Fock components. In ... More
On Fourier and Zeta(s)Dec 22 2001Mar 11 2003We study some of the interactions between the Fourier Transform and the Riemann zeta function (and Dirichlet-Dedekind-Hecke-Tate L-functions)
Quasistatic evolution of a brittle thin filmApr 26 2006This paper deals with the quasistatic crack growth of a homogeneous elastic brittle thin film. It is shown that the quasistatic evolution of a three-dimensional cylinder converges, as its thickness tends to zero, to a two-dimensional quasistatic evolution ... More
Real-Time Model-Checking: Parameters everywhereJan 22 2007Feb 27 2007In this paper, we study the model-checking and parameter synthesis problems of the logic TCTL over discrete-timed automata where parameters are allowed both in the model (timed automaton) and in the property (temporal formula). Our results are as follows. ... More
A pinching theorem for the first eigenvalue of the laplacian on hypersurface of the euclidean spaceSep 18 2006In this paper, we give pinching Theorems for the first nonzero eigenvalue $\lambda$ of the Laplacian on the compact hypersurfaces of the Euclidean space. Indeed, we prove that if the volume of $M$ is 1 then, for any $\epsilon>0$, there exists a constant ... More
Low-lying eigenvalues of semiclassical Schrödinger operator with degenerate wellsFeb 08 2018In this article, we consider the semiclassical Schr\"odinger operator $P = - h^{2} \Delta + V$ in $\mathbb{R}^{d}$ with confining non-negative potential $V$ which vanishes, and study its low-lying eigenvalues $\lambda_{k} ( P )$ as $h \to 0$. First, we ... More
Fast and exact simulation of complex-valued stationary Gaussian processes through embedding circulant matrixApr 01 2016This paper is concerned with the study of the embedding circulant matrix method to simulate stationary complex-valued Gaussian sequences. The method is, in particular, shown to be well-suited to generate circularly-symmetric stationary Gaussian processes. ... More
On submanifolds in locally symmetric spaces of noncompact typeJul 10 2006Jul 29 2009Given a connected, compact, totally geodesic submanifold Y^m of noncompact type inside a compact locally symmetric space of noncompact type X^n, we provide a sufficient condition that ensures that [Y^m] is nonzero in H_m(X^n; R); in low dimensions, our ... More
The semilinear wave equation on asymptotically euclidean manifoldsOct 02 2008We consider the quadratically semilinear wave equation on R^d, d>=3, equipped with a Riemannian metric. This metric is non-trapping and approaches the Euclidean metric polynomially at infinity. Using Mourre estimates and the Kato theory of smoothness, ... More
Feller property and infinitesimal generator of the exploration processDec 09 2005We consider the exploration process associated to the continuous random tree (CRT) built using a Levy process with no negative jumps. This process has been studied by Duquesne, Le Gall and Le Jan. This measure-valued Markov process is a useful tool to ... More
Decay and non-decay of the local energy for the wave equation in the De Sitter - Schwarzschild metricJun 04 2007We describe an expansion of the solution of the wave equation in the De Sitter - Schwarzschild metric in terms of resonances. The main term in the expansion is due to a zero resonance. The error term decays polynomially if we permit a logarithmic derivative ... More
Reversal property of the Brownian treeOct 10 2017We consider the Brownian tree introduced by Aldous and the associated Q-process which consists in an infinite spine on which are grafted independent Brownian trees. We present a reversal procedure on these trees that consists in looking at the tree downward ... More
Homogenization of variational problems in manifold valued BV-spacesApr 03 2008Nov 04 2008This paper extends the result of \cite{BM} on the homogenization of integral functionals with linear growth defined for Sobolev maps taking values in a given manifold. Through a $\Gamma$-convergence analysis, we identify the homogenized energy in the ... More
A variational approach to the local character of G-closure: the convex caseMar 14 2007Aug 21 2007This article is devoted to characterize all possible effective behaviors of composite materials by means of periodic homogenization. This is known as a $G$-closure problem. Under convexity and $p$-growth conditions ($p>1$), it is proved that all such ... More
Eigenvalue pinching and application to the stability and the almost umbilicity of hypersurfacesSep 06 2007Feb 14 2011In this paper we give pinching theorems for the first nonzero eigenvalue of the Laplacian on the compact hypersurfaces of ambient spaces with bounded sectional curvature. As application we deduce rigidity results for stable constant mean curvature hypersurfaces ... More
Superstructures par agrégation contrôlée de nanocolloïdes: caractérisation structurale par diffusion de neutrons aux petits angles et simulation numériqueFeb 01 2011The complexation of micelles or charged nanoparticles with neutral-charged block copolymers in aqueous solutions leads to the formation of colloidal superstructures also termed 'colloidal complexes'. Their primary interest relies in their monodispersity ... More
L'incompressibilite des feuilles de germes de feuilletages holomorphes singuliersDec 06 2006We consider a non-dicritic germ of foliations defined in some ball, with finite number of separatrices and satisfying some additional but generic hypothesis. We prove that there exists an open neighborhood U of the total separatice set S such that each ... More
The Heisenberg-Pauli canonical formalism of quantum field theory in the rigorous setting of nonlinear generalized functions (Part I)Jul 02 2008Sep 07 2008The unmodified Heisenberg-Pauli canonical formalism of quantum field theory applied to a self-interacting scalar boson field is shown to make sense mathematically in a framework of generalized functions adapted to nonlinear operations. The free-field ... More
Semiclassical estimates of the cut-off resolvent for trapping perturbationsJan 26 2012Sep 21 2012This paper is devoted to the study of a semiclassical "black box" operator $P$. We estimate the norm of its resolvent truncated near the trapped set by the norm of its resolvent truncated on rings far away from the origin. For $z$ in the unphysical sheet ... More
Local limits of conditioned Galton-Watson trees I: the infinite spine caseApr 15 2013Oct 16 2013We give a necessary and sufficient condition for the convergence in distribution of a conditioned Galton-Watson tree to Kesten's tree. This yields elementary proofs of Kesten's result as well as other known results on local limit of conditioned Galton-Watson ... More
The first eigenvalue of Dirac and Laplace operators on surfacesSep 18 2006Let $(M,g,\sigma)$ be a compact Riemmannian surface equipped with a spin structure $\sigma$. For any metric $\tilde{g}$ on $M$, we denote by $\mu\_1(\tilde{g})$ (resp. $\lambda\_1(\tilde{g})$) the first positive eigenvalue of the Laplacian (resp. the ... More
Local energy decay for several evolution equations on asymptotically euclidean manifoldsAug 13 2010Let P be a long range metric perturbation of the Euclidean Laplacian on R^d, d>1. We prove local energy decay for the solutions of the wave, Klein-Gordon and Schroedinger equations associated to P. The problem is decomposed in a low and high frequency ... More
Resolvent smoothness and local decay at low energies for the standard model of non-relativistic QEDApr 15 2011We consider an atom interacting with the quantized electromagnetic field in the standard model of non-relativistic QED. The nucleus is supposed to be fixed. We prove smoothness of the resolvent and local decay of the photon dynamics for quantum states ... More
3D-2D analysis of a thin film with periodic microstructureApr 26 2006The purpose of this article is to study the behavior of a heterogeneous thin film whose microstructure oscillates on a scale that is comparable to that of the thickness of the domain. The argument is based on a 3D-2D dimensional reduction through a $\Gamma$-convergence ... More
Low frequency resolvent estimates for long range perturbations of the Euclidean LaplacianMar 31 2009Using Mourre theory, we obtain low frequency resolvent estimates with sharp weights for long range metric perturbations of the flat Laplacian.
Local limits of conditioned Galton-Watson trees II: the condensation caseNov 26 2013We provide a complete picture of the local convergence of critical or subcritical Galton-Watson tree conditioned on having a large number of individuals with out-degree in a given set. The generic case, where the limit is a random tree with an infinite ... More
$β$-coalescents and stable Galton-Watson treesMar 27 2013Jan 07 2015Representation of coalescent process using pruning of trees has been used by Goldschmidt and Martin for the Bolthausen-Sznitman coalescent and by Abraham and Delmas for the $\beta(3/2,1/2)$-coalescent. By considering a pruning procedure on stable Galton-Watson ... More
The forest associated with the record process on a Lévy treeApr 11 2012Dec 17 2012We perform a pruning procedure on a L\'evy tree and instead of throwing away the removed sub-tree, we regraft it on a given branch (not related to the L\'evy tree). We prove that the tree constructed by regrafting is distributed as the original L\'evy ... More
Improved local energy decay for the wave equation on asymptotically Euclidean odd dimensional manifolds in the short range caseJul 26 2011We show improved local energy decay for the wave equation on asymptotically Euclidean manifolds in odd dimensions in the short range case. The precise decay rate depends on the decay of the metric towards the Euclidean metric. We also give estimates of ... More
Homogenization of variational problems in manifold valued Sobolev spacesDec 11 2007Apr 22 2008Homogenization of integral functionals is studied under the constraint that admissible maps have to take their values into a given smooth manifold. The notion of tangential homogenization is defined by analogy with the tangential quasiconvexity introduced ... More
Character decomposition of Potts model partition functions. I. Cyclic geometryMay 04 2006We study the Potts model (defined geometrically in the cluster picture) on finite two-dimensional lattices of size L x N, with boundary conditions that are free in the L-direction and periodic in the N-direction. The decomposition of the partition function ... More
Superintegrable systems with spin and second-order integrals of motionAug 14 2012Jul 16 2014We investigate a quantum nonrelativistic system describing the interaction of two particles with spin 1/2 and spin 0, respectively. We assume that the Hamiltonian is rotationally invariant and parity conserving and identify all such systems which allow ... More
Preheating after Small-Field InflationDec 21 2010Apr 14 2011Whereas preheating after chaotic and hybrid inflation models has been abundantly studied in the literature, preheating in small field inflation models, where the curvature of the inflaton potential is negative during inflation, remains less explored. ... More
Simulation of induction at low magnetic Prandtl numberNov 26 2003We consider the induction of magnetic field in flows of electrically conducting fluid at low magnetic Prandtl number and large kinetic Reynolds number. Using the separation between the magnetic and kinetic diffusive lengthscales, we propose a new numerical ... More
Rigidity of Almost-Isometric Universal CoversSep 10 2014Almost-isometries are quasi-isometries with multiplicative constant one. Lifting a pair of metrics on a compact space gives quasi-isometric metrics on the universal cover. Under some additional hypotheses on the metrics, we show that there is no almost-isometry ... More
Charge transport in purple membrane monolayers: A sequential tunneling approachMay 04 2011Current voltage (I-V) characteristics in proteins can be sensitive to conformational change induced by an external stimulus (photon, odour, etc.). This sensitivity can be used in medical and industrial applications besides shedding new light in the microscopic ... More
Phononic engineering with nanostructures for hot carrier solar cellsNov 02 2006Hot Carrier solar cells have long been recognized as an attractive contender in the search for high efficiency photovoltaic devices but their fabrication requires solution of two important material challenges: finding materials with drastically reduced ... More
Globally monotonic tracking control of multivariable systemsFeb 21 2014In this paper we present a method for designing a linear time invariant (LTI) state-feedback controller to monotonically track a constant step reference at any desired rate of convergence for any arbitrarily assigned initial condition. Necessary and sufficient ... More
Minoration de la resolvante dans le cas captifSep 30 2010In this note, we prove an optimal universal lower bound on the truncated resolvent for semiclassical Schroedinger operators near a trapping energy. In particular, this shows that known upper bounds for hyperbolic trapping are optimal. The proof rely on ... More
An explicit Euler scheme with strong rate of convergence for financial SDEs with non-Lipschitz coefficientsMay 14 2014Apr 10 2016We consider the approximation of stochastic differential equations (SDEs) with non-Lipschitz drift or diffusion coefficients. We present a modified explicit Euler-Maruyama discretisation scheme that allows us to prove strong convergence, with a rate. ... More
Escape probabilities for branching Brownian motion among mild obstaclesMar 19 2010Jan 17 2011We derive asymptotics for the quenched probability that a critical branching Brownian motion killed at a small rate in Poissonian obstacles exits a large domain. Results are formulated in terms of the solution to a semilinear partial differential equation ... More
Lattice Diagram polynomials in one set of variablesMar 27 2001The space $M_{\mu/i,j}$ spanned by all partial derivatives of the lattice polynomial $\Delta_{\mu/i,j}(X;Y)$ is investigated in math.CO/9809126 and many conjectures are given. Here, we prove all these conjectures for the $Y$-free component $M_{\mu/i,j}^0$ ... More
Pruning Galton-Watson Trees and Tree-valued Markov ProcessesJul 02 2010Feb 07 2011We present a new pruning procedure on discrete trees by adding marks on the nodes of trees. This procedure allows us to construct and study a tree-valued Markov process $\{{\cal G}(u)\}$ by pruning Galton-Watson trees and an analogous process $\{{\cal ... More
Spatial heterogeneity in 3D-2D dimensional reductionApr 26 2006A justification of heterogeneous membrane models as zero-thickness limits of a cylindral three-dimensional heterogeneous nonlinear hyperelastic body is proposed in the spirit of Le Dret & Raoult. Specific characterizations of the 2D elastic energy are ... More
Hypersurfaces with small extrinsic radius or large $λ_1$ in Euclidean spacesSep 10 2010Nov 25 2010We prove that hypersurfaces of $\R^{n+1}$ which are almost extremal for the Reilly inequality on $\lambda_1$ and have $L^p$-bounded mean curvature ($p>n$) are Hausdorff close to a sphere, have almost constant mean curvature and have a spectrum which asymptotically ... More
Eigenvalue amplitudes of the Potts model on a torusAug 23 2006We consider the Q-state Potts model in the random-cluster formulation, defined on finite two-dimensional lattices of size L x N with toroidal boundary conditions. Due to the non-locality of the clusters, the partition function Z(L,N) cannot be written ... More
Mean--field limit of a particle approximation of the one-dimensional parabolic--parabolic Keller-Segel model without smoothingDec 20 2017Oct 16 2018In this work, we prove the well--posedness of a singularly interacting stochastic particle system and we establish propagation of chaos result towards the one-dimensional parabolic-parabolic Keller-Segel model.
Mechanical Instabilities of Biological TubesJul 06 2012We study theoretically the shapes of biological tubes affected by various pathologies. When epithelial cells grow at an uncontrolled rate, the negative tension produced by their division provokes a buckling instability. Several shapes are investigated ... More
CMB and SZ effect separation with Constrained Internal Linear CombinationsJun 29 2010The `Internal Linear Combination' (ILC) component separation method has been extensively used on the data of the WMAP space mission, to extract a single component, the CMB, from the WMAP multifrequency data. We extend the ILC approach for reconstructing ... More
Learning to automatically detect features for mobile robots using second-order Hidden Markov ModelsJan 24 2005In this paper, we propose a new method based on Hidden Markov Models to interpret temporal sequences of sensor data from mobile robots to automatically detect features. Hidden Markov Models have been used for a long time in pattern recognition, especially ... More
The Hausdorff measure of stable treesSep 29 2005We study fine properties of the so-called stable trees, which are the scaling limits of critical Galton-Watson trees conditioned to be large. In particular we derive the exact Hausdorff measure function for Aldous' continuum random tree and for its level ... More
A note on Gromov-Hausdorff-Prokhorov distance between (locally) compact measure spacesFeb 24 2012We present an extension of the Gromov-Hausdorff metric on the set of compact metric spaces: the Gromov-Hausdorff-Prokhorov metric on the set of compact metric spaces endowed with a finite measure. We then extend it to the non-compact case by describing ... More
Counting function of characteristic values and magnetic resonancesSep 19 2011We consider the meromorphic operator-valued function 1-K(z) = 1-A(z)/z where A(z) is holomorphic on the domain D, and has values in the class of compact operators acting in a given Hilbert space. Under the assumption that A(0) is a selfadjoint operator ... More
Toward perfect reads: self-correction of short reads via mapping on de Bruijn graphsNov 09 2017Feb 08 2018Motivations Short-read accuracy is important for downstream analyses such as genome assembly and hybrid long-read correction. Despite much work on short-read correction, present-day correctors either do not scale well on large data sets or consider reads ... More
Dimensional reduction for energies with linear growth involving the bending momentNov 05 2007Apr 24 2008A $\Gamma$-convergence analysis is used to perform a 3D-2D dimension reduction of variational problems with linear growth. The adopted scaling gives rise to a nonlinear membrane model which, because of the presence of higher order external loadings inducing ... More
Temporal and Spatial Data Mining with Second-Order Hidden ModelsMay 09 2005In the frame of designing a knowledge discovery system, we have developed stochastic models based on high-order hidden Markov models. These models are capable to map sequences of data into a Markov chain in which the transitions between the states depend ... More
Random Trees, Levy Processes and Spatial Branching ProcessesSep 23 2005We investigate the genealogical structure of general critical or subcritical continuous-state branching processes. Analogously to the coding of a discrete tree by its contour function, this genealogical structure is coded by a real-valued stochastic process ... More
Conditioned Brownian treesJan 05 2005We consider a Brownian tree consisting of a collection of one-dimensional Brownian paths started from the origin, whose genealogical structure is given by the Continuum Random Tree (CRT). This Brownian tree may be generated from the Brownian snake driven ... More
Semiclassical scattering amplitude at the maximum point of the potentialApr 12 2007Apr 13 2007We compute the scattering amplitude for Schr\"odinger operators at a critical energy level, corresponding to the maximum point of the potential. We follow the wrok of Robert and Tamura, '89, using Isozaki and Kitada's representation formula for the scattering ... More
Super-Brownian motion with reflecting historical pathsMar 09 2000We consider super-Brownian motion whose historical paths reflect from each other, unlike those of the usual historical super-Brownian motion. We prove tightness for the family of distributions corresponding to a sequence of discrete approximations but ... More
On the re-rooting invariance property of Levy treesFeb 21 2009We prove a strong form of the invariance under re-rooting of the distribution of the continuous random trees called Levy trees. This extends previous results due to several authors.
A variational approach to some transport inequalitiesAug 30 2015Apr 26 2016We relate transport-entropy inequalities to the study of critical points of functionals defined on the space of probability measures. This approach leads in particular to a new proof of a result by Otto and Villani [43] showing that the logarithmic Sobolev ... More
Estimating magnetic filling factors from Zeeman-Doppler magnetogramsMar 13 2019Low-mass stars are known to have magnetic fields that are believed to be of dynamo origin. Two complementary techniques are principally used to characterise them. Zeeman-Doppler imaging (ZDI) can determine the geometry of the large-scale magnetic field ... More
ABC likelihood-freee methods for model choice in Gibbs random fieldsJul 17 2008Apr 03 2009Gibbs random fields (GRF) are polymorphous statistical models that can be used to analyse different types of dependence, in particular for spatially correlated data. However, when those models are faced with the challenge of selecting a dependence structure ... More
On the Performance of Short Block Codes over Finite-State Channels in the Rare-Transition RegimeMar 27 2014As the mobile application landscape expands, wireless networks are tasked with supporting different connection profiles, including real-time traffic and delay-sensitive communications. Among many ensuing engineering challenges is the need to better understand ... More
Dual-Based Bounds for Resource Allocation in Zero-forcing Beamforming OFDMA-SDMA SystemsDec 20 2012We consider multi-antenna base stations using orthogonal frequency division multiple access and space division multiple access techniques to serve single-antenna users. Some users, called real-time users, have minimum rate requirements and must be served ... More
Entropic Variable Boosting for Explainability and Interpretability in Machine LearningOct 18 2018In this paper, we present a new explainability formalism to make clear the impact of each variable on the predictions given by black-box decision rules. Our method consists in evaluating the decision rules on test samples generated in such a way that ... More
Generalized Mean-payoff and Energy GamesJul 09 2010Oct 02 2010In mean-payoff games, the objective of the protagonist is to ensure that the limit average of an infinite sequence of numeric weights is nonnegative. In energy games, the objective is to ensure that the running sum of weights is always nonnegative. Generalized ... More
Resonances for homoclinic trapped setsMar 24 2016We study semiclassical resonances generated by homoclinic trapped sets. First, under some general assumptions, we prove that there is no resonance in a region below the real axis. Then, we obtain a quantization rule and the asymptotic expansion of the ... More
Aspects of fine-tuning of the Higgs mass within finite field theoriesDec 18 2013We reanalyze the perturbative radiative corrections to the Higgs mass within the Standard Model in the light of the Taylor-Lagrange renormalization scheme. This scheme naturally leads to completely finite corrections, depending on an arbitrary scale. ... More
Foundations of Garside TheorySep 03 2013This text consists of the introduction, table of contents, and bibliography of a long manuscript (703 pages) that is currently submitted for publication. This manuscript develops an extension of Garside's approach to braid groups and provides a unified ... More
Natural decomposition of processes and weak Dirichlet processesMar 26 2004Apr 05 2004A class of stochastic processes, called "weak Dirichlet processes", is introduced and its properties are investigated in detail. This class is much larger than the class of Dirichlet processes. It is closed under C^1$-transformations and under absolutely ... More
First-Passage Time and Large-Deviation Analysis for Erasure Channels with MemoryAug 15 2012Apr 25 2013This article considers the performance of digital communication systems transmitting messages over finite-state erasure channels with memory. Information bits are protected from channel erasures using error-correcting codes; successful receptions of codewords ... More
The star RR Lyr and the Cepheid variables in the era of the space photometry revolutionJun 26 2015The long-term behaviours of the pulsation and Blazhko periods of RR Lyr are investigated by means of Kepler and ground-based observations. The difficulties in detecting additional modes in the Cepheids monitored with CoRoT are discussed.
Accretion in Taurus PMS binaries: a spectroscopic studySep 22 1999We present low-resolution optical spectra of each component of 10 T Tauri (TT) binary systems with separations ranging from 0.9" to 3.5" and located in the Taurus star-forming region. We derive the spectral type and Halpha equivalent width of each component. ... More
Spectral projection, residue of the scattering amplitude, and Schrodinger group expansion for barrier-top resonancesAug 24 2009We study the spectral projection associated to a barrier-top resonance for the semiclassical Schrodinger operator. First, we prove a resolvent estimate for complex energies close to such a resonance. Using that estimate and an explicit representation ... More
A spinorial analogue of Aubin's inequalityAug 12 2003Jun 26 2007Let $(M,g,\si)$ be a compact Riemannian spin manifold of dimension $\geq 2$. For any metric $\tilde g$ conformal to $g$, we denote by $\tilde\lambda$ the first positive eigenvalue of the Dirac operator on $(M,\tilde g,\si)$. We show that $$\inf_{\tilde{g} ... More
Propagation des singularités et résonancesApr 12 2017In the framework of semiclassical resonances, we make more precise the link between polynomial estimates of the extension of the resolvent and propagation of the singularities through the trapped set. This approach makes it possible to eliminate infinity ... More
Automatic sensor-based detection and classification of climbing activitiesJun 23 2015This article presents a method to automatically detect and classify climbing activities using inertial measurement units (IMUs) attached to the wrists, feet and pelvis of the climber. The IMUs record limb acceleration and angular velocity. Detection requires ... More
Delay-Sensitive Communication over Fading Channel: Queueing Behavior and Code Parameter SelectionSep 12 2013This article examines the queueing performance of communication systems that transmit encoded data over unreliable channels. A fading formulation suitable for wireless environments is considered where errors are caused by a discrete channel with correlated ... More
Complex-temperature phase diagram of Potts and RSOS modelsNov 02 2005Feb 17 2006We study the phase diagram of Q-state Potts models, for Q=4 cos^2(PI/p) a Beraha number (p>2 integer), in the complex-temperature plane. The models are defined on L x N strips of the square or triangular lattice, with boundary conditions on the Potts ... More
Selfduality for coupled Potts models on the triangular latticeFeb 16 2004We present selfdual manifolds for coupled Potts models on the triangular lattice. We exploit two different techniques: duality followed by decimation, and mapping to a related loop model. The latter technique is found to be superior, and it allows to ... More
Maximal velocity of photons in non-relativistic QEDOct 18 2011We consider the problem of propagation of photons in the quantum theory of non-relativistic matter coupled to electromagnetic radiation, which is, presently, the only consistent quantum theory of matter and radiation. Assuming that the matter system is ... More