Results for "François Perron"

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Polynomial Pickands functionsJan 15 2016Pickands dependence functions characterize bivariate extreme value copulas. In this paper, we study the class of polynomial Pickands functions. We provide a solution for the characterization of such polynomials of degree at most $m+2$, $m\geq0$, and show ... More
Bayesian inference for bivariate ranksFeb 09 2018A recommender system based on ranks is proposed, where an expert's ranking of a set of objects and a user's ranking of a subset of those objects are combined to make a prediction of the user's ranking of all objects. The rankings are assumed to be induced ... More
Generalized Laplace Inference in Multiple Change-Points ModelsMar 28 2018Under the classical long-span asymptotic framework we develop a class of Generalized Laplace (GL) inference methods for the change-point dates in a linear time series regression model with multiple structural changes analyzed in, e.g., Bai and Perron ... More
Testing for Common Breaks in a Multiple Equations SystemJun 01 2016The issue addressed in this paper is that of testing for common breaks across or within equations of a multivariate system. Our framework is very general and allows integrated regressors and trends as well as stationary regressors. The null hypothesis ... More
Continuous Record Asymptotics for Structural Change ModelsMar 28 2018For a partial structural change in a linear regression model with a single break, we develop a continuous record asymptotic framework to build inference methods for the break date. We have T observations with a sampling frequency h over a fixed time horizon ... More
Continuous Record Laplace-based Inference about the Break Date in Structural Change ModelsApr 01 2018Building upon the continuous record asymptotic framework recently introduced by Casini and Perron (2017a) for inference in structural change models, we propose a Laplace-based (Quasi-Bayes) procedure for the construction of the estimate and confidence ... More
Structural Breaks in Time SeriesMay 10 2018This chapter covers methodological issues related to estimation, testing and computation for models involving structural changes. Our aim is to review developments as they relate to econometric applications based on linear models. Substantial advances ... More
Random walk driven by the simple exclusion processApr 16 2014Oct 30 2015We prove a strong law of large numbers and an annealed invariance principle for a random walk in a one-dimensional dynamic random environment evolving as the simple exclusion process with jump parameter $\gamma$. First, we establish that if the asymptotic ... More
Testing for Common Breaks in a Multiple Equations SystemJun 01 2016Jan 11 2018The issue addressed in this paper is that of testing for common breaks across or within equations of a multivariate system. Our framework is very general and allows integrated regressors and trends as well as stationary regressors. The null hypothesis ... More
Functions of degree 4e that are not APN infinitely oftenFeb 02 2016We prove a necessary condition for some polynomials of degree 4e (e an odd number) to be APN over F q n for large n, and we investigate the polynomials f of degree 12.
Open Access and Discovery Tools: How do Primo Libraries Manage Green Open Access Collections?Sep 15 2015Feb 28 2016Scholarly Open Access repositories contain lots of treasures including rare or otherwise unpublished materials and articles that scholars self-archive, often as part of their institution's mandate. But it can be hard to discover this material unless users ... More
Fourier-based schemes for computing the mechanical response of composites with accurate local fieldsDec 21 2014We modify the Green operator involved in Fourier-based computational schemes in elasticity, in 2D and 3D. The new operator is derived by expressing continuum mechanics in terms of centered differences on a rotated grid. Use of the modified Green operator ... More
A natural generalization of Balanced TableauxJul 23 2014Mar 10 2016We introduce the notion of "type" of a tableau, that allows us to define new families of tableaux including both balanced and standard Young tableaux. We use these new objects to describe the set of reduced decompositions of any permutation. We then generalize ... More
Présentation des groupes de tresses purs et de certaines de leurs extensionsNov 27 2015Jan 07 2016This paper dates back to 1999 but was never published. The major part of it was included in the joint paper [Digne-Gomi, Presentation of pure braid groups, J. Knot Theory and its Ramifications 10 (2001) 609--623]. Sections 2 and 6 were not included there. ... More
PSF and field of view characteristics of imaging and nulling interferometersApr 01 2010In this communication are presented some complements to a recent paper entitled "Simple Fourier optics formalism for high angular resolution systems and nulling interferometry", dealing with imaging and nulling capacities of a few types of multi-aperture ... More
Noisy data clusters are hollowJun 10 2015Mar 10 2016A new vision in multidimensional statistics is proposed impacting severalareas of application. In these applications, a set of noisy measurementscharacterizing the repeatable response of a process is known as a realizationand can be seen as a single point ... More
Thermoelectric efficiency in the space-charge-limited transport regime in semiconductorsSep 27 2012The thermoelectric efficiency of semiconductors is usually considered in the ohmic electronic transport regime, which is achieved through high doping. Here we consider the opposite regime of low doping where the current-voltage characteristics are nonlinear ... More
On parametric extensions over number fieldsFeb 22 2016Mar 07 2016Given a number field $F$, a finite group $G$ and an indeterminate $T$, {\it{a $G$-parametric extension over $F$}} is a finite Galois extension $E/F(T)$ with Galois group $G$ and $E/F$ regular that has all the Galois extensions of $F$ with Galois group ... More
Hilbert specialization results with local conditionsDec 24 2014Feb 15 2016Given a field $k$ of characteristic zero and an indeterminate $T$, the main topic of the paper is the construction of specializations of any given finite extension of $k(T)$ of degree $n$ that are degree $n$ field extensions of $k$ with specified local ... More
Asymptotic direction for random walks in random environmentsDec 16 2005Dec 11 2007In this paper we study the property of asymptotic direction for random walks in random i.i.d. environments (RWRE). We prove that if the set of directions where the walk is transient is non empty and open, the walk admits an asymptotic direction. The main ... More
An introduction to finite volumes for gas dynamicsJan 22 2011We propose an elementary introduction to the finite volume method in the context of gas dynamics conservation laws. Our approach is founded on the advection equation, the exact integration of the associated Cauchy problem, and the so-called upwind scheme ... More
Frobenius distribution for pairs of elliptic curves and exceptional isogeniesNov 11 2014Let E and E' be two elliptic curves over a number field. We prove that the reductions of E and E' at a finite place p are geometrically isogenous for infinitely many p, and draw consequences for the existence of supersingular primes. This result is an ... More
A remark on the Torelli theorem for cubic fourfoldsSep 20 2012In this note, we give a short proof of the Torelli theorem for cubic fourfolds that relies on the global Torelli theorem for irreducible holomorphic symplectic varieties proved by Verbitsky.
Information-theoretical label embeddings for large-scale image classificationJul 19 2016We present a method for training multi-label, massively multi-class image classification models, that is faster and more accurate than supervision via a sigmoid cross-entropy loss (logistic regression). Our method consists in embedding high-dimensional ... More
Xception: Deep Learning with Depthwise Separable ConvolutionsOct 07 2016Oct 11 2016We present an interpretation of Inception modules in convolutional neural networks as being an intermediate step in-between regular convolution and the \textit{depthwise separable convolution} operation (a depthwise convolution followed by a pointwise ... More
Edwards curves and CM curvesApr 15 2009Edwards curves are a particular form of elliptic curves that admit a fast, unified and complete addition law. Relations between Edwards curves and Montgomery curves have already been described. Our work takes the view of parameterizing elliptic curves ... More
Coarse Lipschitz embeddings of James spacesJun 07 2016We prove that, for $1 < p \neq q < \infty$, there does not exist any coarse Lipschitz embedding between the two James spaces $J_p$ and $J_q$, and that, for $1 < p < q < \infty$ and $1 < r < \infty$ such that $r \notin \{p,q\}$, $J_r$ does not coarse Lipschitz ... More
The $L^1$ gradient flow of a generalized scale invariant Willmore energy for radially non increasing functionsNov 13 2014Jul 06 2016We use the minimizing movement theory to study the gradient flow associated with a non-regular relaxation of a geometric functional derived from the Willmore energy. Thanks to the coarea formula, one can define a Willmore energy on regular functions of ... More
An inverse scattering problem for short-range systems in a time-periodic electric fieldJun 20 2005We consider the time-dependent Hamiltonian $H(t)= {1 \over 2} p^2 -E(t) \cdot x + V(t,x)$ on $L^2(R^n)$, where the external electric field $E(t)$ and the short-range electric potential $V(t,x)$ are time-periodic with the same period. It is well-known ... More
Drastic fall-off of the thermal conductivity for disordered lattices in the limit of weak anharmonic interactionsMar 15 2012Apr 16 2014We study the thermal conductivity, at fixed positive temperature, of a disordered lattice of harmonic oscillators, weakly coupled to each other through anharmonic potentials. The interaction is controlled by a small parameter $\epsilon > 0$. We rigorously ... More
Classical and quantum systems: transport due to rare eventsJan 20 2017We review possible mechanisms for energy transfer based on 'rare' or 'non-perturbative' effects, in physical systems that present a many-body localized phenomenology. The main focus is on classical systems, with or without quenched disorder. For non-quantum ... More
Présentations duales des groupes de tresses de type affine $\tilde A$Feb 07 2004Sep 06 2005In the present paper we define dual monoids for all Artin-Tits groups and we prove that for the type $\tilde A_n$ we get a (quasi)-Garside structure. Such a structure provides normal forms for the Artin-Tits group elements and allows to solve some questions ... More
Régulateurs modulaires explicites via la méthode de Rogers-ZudilinFeb 09 2016We compute the regulator of Beilinson-Deninger-Scholl elements in terms of special values of L-functions of modular forms, using the Rogers-Zudilin method.
A characterization of groups of parahoric typeFeb 15 2012May 09 2015Let F be a local henselian nonarchimedean field of residual field k, and let G be the group of F-points of a connected reductive group defined over F. It is well-known that the quotient of any parahoric subgroup of G by its first congruence subgroup is ... More
Equivalent partial differential equations of a lattice Boltzmann schemeJun 08 2018We show that when we formulate the lattice Boltzmann equation with a small time step $\Delta$t and an associated space scale $\Delta$x, a Taylor expansion joined with the so-called equivalent equation methodology leads to establish macroscopic fluid equations ... More
De Newton à Boltzmann et Einstein: validation des modèles cinétiques et de diffusionNov 30 2014The kinetic theory of Maxwell and Boltzmann has been the subject of major scientific controversies. The alleged incompatibility between the reversible nature of the equations of classical mechanics and the increase of entropy, which, in the kinetic theory ... More
Thermoplasticity as a nonsmooth phenomenonDec 16 2017Feb 20 2018This paper develops the multisymplectic formulation of nonsmooth elastoplastic phenomena, where the plastic deformation and the associated thermodynamic entropy evolve by jumps.
Borne sur le degré des polynômes presque parfaitement non-linéairesMay 09 2006May 02 2008The vectorial Boolean functions are employed in cryptography to build block coding algorithms. An important criterion on these functions is their resistance to the differential cryptanalysis. Nyberg defined the notion of almost perfect non-linearity (APN) ... More
Efficient tensor tomography in fan-beam coordinates. II: Attenuated transformsApr 26 2017Nov 02 2017This article extends the author's past work [Inv. Probl. Imaging, 10:2 (2016), 433--459] to attenuated X-ray transforms, where the attenuation is complex-valued and only depends on position. We give a positive and constructive answer to the attenuated ... More
Numerical implementation of geodesic X-ray transforms and their inversionSep 24 2013Apr 16 2014We present a numerical implementation of the geodesic ray transform and its inversion over functions and solenoidal vector fields on two-dimensional Riemannian manifolds. For each problem, inversion formulas previously derived in \cite{Pestov2004,Krishnan2010} ... More
Jacobi's bound and normal forms computations. A historical surveyNov 13 2009May 01 2010Jacobi is one of the most famous mathematicians of his century. His name is attached to many results in various fields of mathematics and his complete works in seven volumes have been available since the end of the XIXth century and are very often quoted ... More
An inhomogeneous, $L^2$ critical, nonlinear Schrödinger equationOct 05 2011An inhomogeneous nonlinear Schr\"odinger equation is considered, that is invariant under $L^2$ scaling. The sharp condition for global existence of $H^1$ solutions is established, involving the $L^2$ norm of the ground state of the stationary equation. ... More
Recent Results on the Periodic Lorentz GasJun 01 2009Jun 25 2009The Drude-Lorentz model for the motion of electrons in a solid is a classical model in statistical mechanics, where electrons are represented as point particles bouncing on a fixed system of obstacles (the atoms in the solid). Under some appropriate scaling ... More
On the Periodic Lorentz Gas and the Lorentz Kinetic EquationMar 27 2007We prove that the Boltzmann-Grad limit of the Lorentz gas with periodic distribution of scatterers cannot be described with a linear Boltzmann equation. This is at variance with the case of a Poisson distribution of scatterers, for which the convergence ... More
From the Kinetic Theory of Gases to Continuum MechanicsSep 22 2010Recent results on the fluid dynamic limits of the Boltzmann equation based on the DiPerna-Lions theory of renormalized solutions are reviewed in this paper, with an emphasis on regimes where the velocity field behaves to leading order like that of an ... More
Distinction of the Steinberg representation III: the tamely ramified caseAug 28 2014Apr 20 2016Let $F$ be a nonarchimedean local field, let $E$ be a Galois quadratic extension of $F$ and let $G$ be a quasisplit group defined over $F$; a conjecture by Dipendra Prasad states that the Steinberg representation of $G(E)$ is then $\chi$-distinguished ... More
On the Dynamics of Large Particle Systems in the Mean Field LimitJan 23 2013This course explains how the usual mean field evolution partial differential equations (PDEs) in Statistical Physics - such as the Vlasov-Poisson system, the vorticity formulation of the two-dimensional Euler equation for incompressible fluids, or the ... More
The radiation condition at infinity for the high-frequency Helmholtz equation with source term: a wave packet approachMar 16 2005We consider the high-frequency Helmholtz equation with a given source term, and a small absorption parameter $\a>0$. The high-frequency (or: semi-classical) parameter is $\eps>0$. We let $\eps$ and $\a$ go to zero simultaneously. We assume that the zero ... More
Strip maps of small surfaces are convexJun 26 2015The strip map is a natural map from the arc complex of a bordered hyperbolic surface $S$ to the vector space of infinitesimal deformations of $S$. We prove that the image of the strip map is a convex hypersurface when $S$ is a surface of small complexity: ... More
Lengthening deformations of singular hyperbolic toriJun 18 2015Let $S$ be a torus with a hyperbolic metric admitting one puncture or cone singularity. We describe which infinitesimal deformations of $S$ lengthen (or shrink) all closed geodesics. We also study how the answer degenerates when $S$ becomes Euclidean, ... More
Transport equations for superconductors in the presence of spin interactionMar 07 2014May 27 2014Quasi-classical theory of superconductivity provides a powerful and yet simple description of the superconductivity phenomenology. In particular, the Eilenberger and Usadel equations provide a neat simplification of the description of the superconducting ... More
Generalized Kirchhoff approximation for Helmholtz equationFeb 15 2014We give integral formulas to approximate solutions of Dirichlet and Neumann problems for Helmholtz equation at high frequencies. These approximations are valid in the complementary of a union of convex compact obstacles. The first step of the iterative ... More
Partial Riemann problem, boundary conditions, and gas dynamicsJan 14 2011We introduce in this contribution the notion of partial Riemann problem. Recall that the Riemann problem describes a shock tube interaction between two given states ; the partial Riemann problem is a generalization of the previous concept and introduces ... More
Conservation Laws Invariant for Galileo Group; Cemracs Preliminary resultsJan 13 2011We propose a notion of hyperbolic system of conservation laws invariant for the Galileo group of transformations. We show that with natural physical and mathematical hypotheses, such a system conducts to the gas dynamics equations or to exotic systems ... More
Stable lattice Boltzmann schemes with a dual entropy approach for monodimensional nonlinear wavesDec 09 2010Mar 08 2013We follow the mathematical framework proposed by Bouchut and present in this contribution a dual entropy approach for determining equilibrium states of a lattice Boltzmann scheme. This method is expressed in terms of the dual of the mathematical entropy ... More
Twists of superelliptic curves without rational pointsMar 23 2016Aug 15 2016Let $n\geq 2$ be an integer, $F$ a number field, $O_F$ the integral closure of $\mathbb{Z}$ in $F$ and $N$ a positive multiple of $n$. The paper deals with degree $N$ polynomials $P(T) \in O_F[T]$ such that the superelliptic curve $Y^n=P(T)$ has twists ... More
On the Picard number of K3 surfaces over number fieldsNov 17 2011We discuss some aspects of the behavior of specialization at a finite place of N\'eron-Severi groups of K3 surfaces over number fields. We give optimal lower bounds for the Picard number of such specializations, thus answering a question of Elsenhans ... More
Non-parametric latent modeling and network clusteringMar 09 2016The paper exposes a non-parametric approach to latent and co-latent modeling of bivariate data, based upon alternating minimization of the Kullback-Leibler divergence (EM algorithm) for complete log-linear models. For categorical data, the iterative algorithm ... More
Intrinsic Stratifications of Analytic VarietiesFeb 02 2014Feb 18 2014By attaching a Lie algebra of germs of analytic vector fields to every point of a (real or complex) analytic variety V we construct the Nagano foliation of the variety. We prove that the Nagano foliation of V is a stratification. The treatment of the ... More
Nonlinear fourth order Taylor expansion of lattice Boltzmann schemesMar 29 2019We propose a formal expansion of multiple relaxation times lattice Boltzmann schemes in terms of a single infinitesimal numerical variable. The result is a system of partial differential equations for the conserved moments of the lattice Boltzmann scheme. ... More
Gromov width and uniruling for orientable Lagrangian surfacesJan 09 2014Sep 08 2014We prove a conjecture of Barraud-Cornea for orientable Lagrangian surfaces. As a corollary, we obtain that displaceable Lagrangian 2--tori have finite Gromov width. In order to do so, we adapt the pearl complex of Biran-Cornea to the non-monotone situation ... More
Response to a small external force and fluctuations of a passive particle in a one-dimensional diffusive environmentSep 26 2017Apr 13 2018We investigate the long time behavior of a passive particle evolving in a one-dimensional diffusive random environment, with diffusion constant $D$. We consider two cases: (a) The particle is pulled forward by a small external constant force, and (b) ... More
Energy fluctuations in simple conduction modelsDec 02 2011Feb 15 2013We introduce a class of stochastic weakly coupled map lattices, as models for studying heat conduction in solids. Each particle on the lattice evolves according to an internal dynamics that depends on its energy, and exchanges energy with its neighboors ... More
Subdiffusive behavior generated by irrational rotationsDec 17 2007Jul 14 2011The origin of deterministic diffusion is a matter of discussion. We study the asymptotic distributions of the sums $y_n(x)=\sum_{k=0}^{n-1}\psi (x+k\alpha)$, where $\psi$ is a periodic function of bounded variation and $\alpha$ an irrational number. It ... More
Formes quadratiques de discriminants emboîtésFeb 03 2014Quadratic forms with embedded discriminants. Integral binary quadratic forms have multiple applications, for example in factorization or cryptography. The Nice family of cryptographic systems makes use of quadratic forms with different discriminants $\pm ... More
Polyhedral realisation of hyperbolic metrics with conical singularities on compact surfacesMay 15 2006Aug 31 2006A Fuchsian polyhedron in hyperbolic space is a polyhedral surface invariant under the action of a Fuchsian group of isometries (i.e. a group of isometries leaving globally invariant a totally geodesic surface, on which it acts cocompactly). The induced ... More
Non-critical equivariant L-values of modular abelian varietiesFeb 18 2014Dec 12 2018We prove an equivariant version of Beilinson's conjecture on non-critical $L$-values of strongly modular abelian varieties over number fields. As an application, we prove a weak version of Zagier's conjecture on $L(E,2)$ and Deninger's conjecture on $L(E,3)$ ... More
Open Questions for operators related to Rectangular Catalan CombinatoricsMar 14 2016Mar 20 2016We formulate many open questions regarding the Schur positivity of the effect of interesting operators on symmetric functions, and give supporting evidence for why one should expect such behavior.
On the Malle conjecture and the Grunwald problemDec 29 2018We contribute to the Malle conjecture on the number N (K, G, y) of finite Galois extensions E of some number field K of finite group G and of discriminant of norm |N K/Q (d E)| $\le$ y. We prove the lower bound part of the conjecture for every group G ... More
On the Mahler measure associated to $X_1(13)$Mar 16 2015Mar 23 2015We show that the Mahler measure of a defining equation of the modular curve $X_1(13)$ is equal to the derivative at $s=0$ of the $L$-function of a cusp form of weight 2 and level 13 with integral Fourier coefficients. The proof combines Deninger's method, ... More
Regulators of Siegel units and applicationsApr 30 2015We present a formula for the regulator of two arbitrary Siegel units in terms of L-values of pairwise products of Eisenstein series of weight one. We give applications to Boyd's conjectures and Zagier's conjectures for elliptic curves of conductor 14, ... More
On the zero locus of normal functions and the étale Abel-Jacobi mapFeb 11 2009Jun 30 2009We investigate questions of an arithmetic nature related to the Abel-Jacobi map. We give a criterion for the zero locus of a normal function to be defined over a number field, and we give some comparison theorems with the Abel-Jacobi map coming from continuous ... More
Some results about ergodicity in shape for a crystal growth modelNov 06 2012We study a crystal growth Markov model proposed by Gates and Westcott (\cite{Kinetics1}, \cite{Kinetics2}). This is an aggregation process where particles are packed in a square lattice accordingly to prescribed deposition rates. This model is parametrized ... More
Optimal Hoeffding bounds for discrete reversible Markov chainsMay 14 2004We build optimal exponential bounds for the probabilities of large deviations of sums \sum_{k=1}^nf(X_k) where (X_k) is a finite reversible Markov chain and f is an arbitrary bounded function. These bounds depend only on the stationary mean E_{\pi}f, ... More
Predicting the dynamics of 2d objects with a deep residual networkOct 13 2016We investigate how a residual network can learn to predict the dynamics of interacting shapes purely as an image-to-image regression problem. With a simple 2d physics simulator, we generate short sequences composed of rectangles put in motion by applying ... More
The fusion rules of some free wreath product quantum groups and applicationsNov 24 2013Jul 02 2014In this paper we find the fusion rules of the free wreath products $\widehat{\Gamma}\wr_*S_N^+$ for any (discrete) group $\Gamma$. To do this we describe the spaces of intertwiners between basic corepresentations which allows us to identify the irreducible ... More
Strict $ω$-categories are monadic over polygraphsJun 01 2016Jun 02 2016We give a direct proof that the category of strict $\omega$-categories is monadic over the category of polygraphs.
A Z-prime interpretation of Bd->K*mu+mu- data and consequences for high energy collidersDec 09 2013In this note, I examine the possible consequences for high energy colliders of a Z-prime interpretation of the LHCb anomaly observed in the K*mu+mu- final state. Two examples are elaborated in the framework of the so-called 331 model. In the first one ... More
The effect of the vertical part of the path on the real time Feynman rules in finite temperature field theoryDec 21 1994The effect of the contribution of the vertical part of the real time path is studied completely in the case of two points functions. Indeed, this vertical part generally contributes in the calculation of a given graph. Moreover, this contribution is essential ... More
On hyperbolic systems with entropy velocity covariant under the action of a groupSep 11 2013For hyperbolic systems of conservation laws in one space dimension with a mathematical entropy, we define the notion of entropy velocity. Then we give sufficient conditions for such a system to be covariant under the action of a group of space-time transformations. ... More
Unique ergodicity of asynchronous rotations, and applicationSep 15 2016The main result of this paper is an analogue for a continuous family of tori of Kronecker-Weyl's unique ergodicity of irrational rotations. We show that the notion corresponding in this setup to irrationality, namely asynchronicity, is satisfied in some ... More
Fractional triangle decompositions in graphs with large minimum degreeMar 27 2015Jul 21 2015A triangle decomposition of a graph is a partition of its edges into triangles. A fractional triangle decomposition of a graph is an assignment of a non-negative weight to each of its triangles such that the sum of the weights of the triangles containing ... More
Asymptotic analysis of the role of spatial sampling for covariance parameter estimation of Gaussian processesJan 18 2013Dec 08 2014Covariance parameter estimation of Gaussian processes is analyzed in an asymptotic framework. The spatial sampling is a randomly perturbed regular grid and its deviation from the perfect regular grid is controlled by a single scalar regularity parameter. ... More
Stereotype bias: a simple formal modelApr 03 2010Minimizing the relative inertia of a statistical group with respect to the inertia of the overall sample defines an unique point, the in-focus, which constitutes a context-dependent measure of typical group tendency, biased in comparison to the group ... More
On the Schoenberg Transformations in Data Analysis: Theory and IllustrationsApr 01 2010Apr 02 2010The class of Schoenberg transformations, embedding Euclidean distances into higher dimensional Euclidean spaces, is presented, and derived from theorems on positive definite and conditionally negative definite matrices. Original results on the arc lengths, ... More
Euclidean Distances, soft and spectral Clustering on Weighted GraphsJul 06 2010We define a class of Euclidean distances on weighted graphs, enabling to perform thermodynamic soft graph clustering. The class can be constructed form the "raw coordinates" encountered in spectral clustering, and can be extended by means of higher-dimensional ... More
Non-critical equivariant L-values of modular abelian varietiesFeb 18 2014We prove an equivariant version of Beilinson's conjecture on non-critical $L$-values of strongly modular abelian varieties over number fields. As an application, we prove a weak version of Zagier's conjecture on $L(E,2)$ and Deninger's conjecture on $L(E,3)$ ... More
Energy transport through rare collisionsJun 29 2011Jul 14 2011We study a one-dimensional hamiltonian chain of masses perturbed by an energy conserving noise. The dynamics is such that, according to its hamiltonian part, particles move freely in cells and interact with their neighbors through collisions, made possible ... More
Lattices of minimal covolume in SL_n(R)May 26 2017Sep 04 2017The objective of this paper is to determine the lattices of minimal covolume in SL_n(R), for n greater than 3. The answer turns out to be the simplest one: SL_n(Z) is, up to automorphism, the unique lattice of minimal covolume in SL_n(R). In particular, ... More
Fuchsian polyhedra in Lorentzian space-formsFeb 18 2007Feb 27 2009Let S be a compact surface of genus >1, and g be a metric on S of constant curvature K\in\{-1,0,1\} with conical singularities of negative singular curvature. When K=1 we add the condition that the lengths of the contractible geodesics are >2\pi. We prove ... More
Deforming ideal solid toriNov 16 2009We describe the deformation space of a solid torus with boundary modelled on convex ideal hyperbolic polyhedra. This deformation space is given by natural Gauss--Bonnet type inequalities on the dihedral angles. The result extends to solid tori with an ... More
Veering triangulations and Cannon-Thurston mapsJun 10 2015Any hyperbolic surface bundle over the circle gives rise to a continuous surjection from the circle to the sphere, by work of Cannon and Thurston. We prove that the order in which this surjection fills out the sphere is dictated by a natural triangulation ... More
On the modularity of endomorphism algebrasMay 23 2017Jun 29 2017We use the adelic language to show that any homomorphism between Jacobians of modular curves arises from a linear combination of Hecke modular correspondences. The proof is based on a study of the actions of $\mathrm{GL}_2$ and Galois on the \'etale cohomology ... More
Errata à ``Sur les représentations non ramifiées des groupes réductifs $p$-adiques; l'exemple de ${\rm GSp}(4)$''Oct 11 2004We correct two errors in the paper "Sur les repr\'esentations non ramifi\'ees des groupes r\'eductifs p-adiques; l'exemple de GSp(4)": the first in the study of an involution on the irreducible unramified representations of a semi-simple group, the second ... More
An Alternative Matting LaplacianMay 16 2016Cutting out and object and estimate its transparency mask is a key task in many applications. We take on the work on closed-form matting by Levin et al., that is used at the core of many matting techniques, and propose an alternative formulation that ... More
Eigenvalue varieties of Brunnian linksDec 10 2015In this article, it is proved that the eigenvalue variety of the exterior of a nontrivial, non-Hopf, Brunnian link in $\mathbb{S}^{3}$ contains a nontrivial component of maximal dimension. This generalises, for Brunnian links, the nontriviality of the ... More
A new family of posets generalizing the weak order on some Coxeter groupsAug 25 2015Oct 22 2015We construct a poset from a simple acyclic digraph together with a valuation on its vertices, and we compute the values of its M\"obius function. We show that the weak order on Coxeter groups of type A, B, affine A, and the flag weak order on the wreath ... More
Magneto-electric coupling in a two-dimensional ballistic Josephson junction with in-plane magnetic textureAug 20 2014We study a Josephson junction made with a spin-textured bridge, when both Rashba and Zeeman interactions combine to generate a magneto-electric coupling between the superconducting current and the in-plane magnetic texture in the normal region. In particular, ... More
Cyclic surfaces and Hitchin components in rank 2Jun 18 2014Jul 05 2016We prove that given a Hitchin representation in a real split rank 2 group $\mathsf G_0$, there exists a unique equivariant minimal surface in the corresponding symmetric space. As a corollary, we obtain a parametrization of the Hitchin components by a ... More
Continuous inverse regressionSep 02 2014Jun 01 2015We provide new theoretical results in the field of inverse regression methods for dimension reduction. Our approach is based on the study of some empirical processes that lie close to a certain dimension reduction subspace, called the central subspace. ... More