Results for "Raphaël Huser"

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Modeling spatial processes with unknown extremal dependence classMar 17 2017Sep 05 2017Many environmental processes exhibit weakening spatial dependence as events become more extreme. Well-known limiting models, such as max-stable or generalized Pareto processes, cannot capture this, which can lead to a preference for models that exhibit ... More
A spliced Gamma-Generalized Pareto model for short-term extreme wind speed probabilistic forecastingOct 09 2018Feb 15 2019Renewable sources of energy such as wind power have become a sustainable alternative to fossil fuel-based energy. However, the uncertainty and fluctuation of the wind speed derived from its intermittent nature bring a great threat to the wind power production ... More
Bayesian model averaging over tree-based dependence structures for multivariate extremesMay 30 2017Jul 22 2018Describing the complex dependence structure of extreme phenomena is particularly challenging. To tackle this issue we develop a novel statistical algorithm that describes extremal dependence taking advantage of the inherent hierarchical dependence structure ... More
INLA goes extreme: Bayesian tail regression for the estimation of high spatio-temporal quantilesFeb 04 2018This work has been motivated by the challenge of the 2017 conference on Extreme-Value Analysis (EVA2017), with the goal of predicting daily precipitation quantiles at the $99.8\%$ level for each month at observed and unobserved locations. We here develop ... More
Likelihood estimators for multivariate extremesNov 13 2014Jun 16 2015The main approach to inference for multivariate extremes consists in approximating the joint upper tail of the observations by a parametric family arising in the limit for extreme events. The latter may be expressed in terms of componentwise maxima, high ... More
Approximate Bayesian inference for spatial flood frequency analysisJul 10 2019Extreme floods cause casualties, widespread property damage, and damage to vital civil infrastructure. Predictions of extreme floods within gauged and ungauged catchments is crucial to mitigate these disasters. A Bayesian framework is proposed for predicting ... More
Space-time modelling of extreme eventsJan 16 2012Max-stable processes are the natural analogues of the generalized extreme-value distribution for the modelling of extreme events in space and time. Under suitable conditions, these processes are asymptotically justified models for maxima of independent ... More
Local likelihood estimation of complex tail dependence structures, applied to U.S. precipitation extremesOct 02 2017Jul 05 2018To model the complex non-stationary dependence structure of precipitation extremes over the entire contiguous U.S., we propose a flexible local approach based on factor copula models. Our sub-asymptotic spatial modeling framework yields non-trivial tail ... More
Local likelihood estimation of complex tail dependence structures, applied to U.S. precipitation extremesOct 02 2017Mar 25 2019To disentangle the complex non-stationary dependence structure of precipitation extremes over the entire contiguous U.S., we propose a flexible local approach based on factor copula models. Our sub-asymptotic spatial modeling framework yields non-trivial ... More
High-order Composite Likelihood Inference for Max-Stable Distributions and ProcessesNov 01 2014Aug 19 2015In multivariate or spatial extremes, inference for max-stable processes observed at a large collection of locations is among the most challenging problems in computational statistics, and current approaches typically rely on less expensive composite likelihoods ... More
A spliced Gamma-Generalized Pareto model for short-term extreme wind speed probabilistic forecastingOct 09 2018Jun 29 2019Renewable sources of energy such as wind power have become a sustainable alternative to fossil fuel-based energy. However, the uncertainty and fluctuation of the wind speed derived from its intermittent nature bring a great threat to the wind power production ... More
Bayesian Modeling of Air Pollution Extremes Using Nested Multivariate Max-Stable ProcessesMar 18 2018Capturing the potentially strong dependence among the peak concentrations of multiple air pollutants across a spatial region is crucial for assessing the related public health risks. In order to investigate the multivariate spatial dependence properties ... More
A Hierarchical Max-infinitely Divisible Process for Extreme Areal Precipitation Over WatershedsMay 16 2018Feb 19 2019Understanding the spatial extent of extreme precipitation is necessary for determining flood risk and adequately designing infrastructure (e.g., stormwater pipes) to withstand such hazards. While environmental phenomena typically exhibit weakening spatial ... More
Full likelihood inference for max-stable dataMar 25 2017Jul 13 2018We show how to perform full likelihood inference for max-stable multivariate distributions or processes based on a stochastic Expectation-Maximisation algorithm, which combines statistical and computational efficiency in high-dimensions. The good performance ... More
Modeling soil organic carbon with Quantile Regression: Dissecting predictors' effects on carbon stocksAug 13 2017Soil Organic Carbon (SOC) estimation is crucial to manage both natural and anthropic ecosystems and has recently been put under the magnifying glass after the Paris agreement 2016 due to its relationship with greenhouse gas. Statistical applications have ... More
Factor Copula Models for Replicated Spatial DataNov 10 2015Jul 10 2016We propose a new copula model that can be used with replicated spatial data. Unlike the multivariate normal copula, the proposed copula is based on the assumption that a common factor exists and affects the joint dependence of all measurements of the ... More
Spectral projections of the complex cubic oscillatorOct 17 2013We prove the spectral instability of the complex cubic oscillator $-\frac{d^2}{dx^2}+ix^3+i\alpha x$ for non-negative values of the parameter $\alpha$, by getting the exponential growth rate of $\|\Pi_n(\alpha)\|$, where $\Pi_n(\alpha)$ is the spectral ... More
A Lagrangian approach for the compressible Navier-Stokes equationsJan 30 2012Sep 25 2014Here we investigate the Cauchy problem for the barotropic Navier-Stokes equations in R^n, in the critical Besov spaces setting. We improve recent results as regards the uniqueness condition: initial velocities in critical Besov spaces with (not too) \emph{negative} ... More
Noise-stability and central limit theorems for effective resistance of random electric networksJun 18 2012Mar 15 2016We investigate the (generalized) Walsh decomposition of point-to-point effective resistances on countable random electric networks with i.i.d. resistances. We show that it is concentrated on low levels, and thus point-to-point effective resistances are ... More
Arbitrary threshold widths for monotone symmetric propertiesJan 06 2006We investigate the threshold widths of some symmetric properties which range asymptotically between 1/\sqrt{n} and 1/(log n). These properties are built using a combination of failure sets arising from reliability theory. This combination of sets is simply ... More
Similarity results for operators of class $C_0$ and the algebra $H^\infty(T)$Aug 16 2012May 22 2014Given two multiplicity-free operators $T_1$ and $T_2$ of class $C_0$ having the same finite Blaschke product as minimal function, the operator algebras $H^\infty(T_1)$ and $H^\infty(T_2)$ are isomorphic and $T_1$ is similar to $T_2$. We find conditions ... More
Hierarchical Archimax copulasJul 03 2017Dec 20 2017The class of Archimax copulas is generalized to hierarchical Archimax copulas in two ways. First, a hierarchical construction of $d$-norm generators is introduced to construct hierarchical stable tail dependence functions which induce a hierarchical structure ... More
Point process-based modeling of multiple debris flow landslides using INLA: an application to the 2009 Messina disasterAug 10 2017We develop a stochastic modeling approach based on spatial point processes of log-Gaussian Cox type for a collection of around 5000 landslide events provoked by a precipitation trigger in Sicily, Italy. Through the embedding into a hierarchical Bayesian ... More
Completely bounded isomorphisms of operator algebras and similarity to complete isometriesJan 03 2014May 22 2014A well-known theorem of Paulsen says that if $\mathcal{A}$ is a unital operator algebra and $\phi:\mathcal{A}\to B(\mathcal{H})$ is a unital completely bounded homomorphism, then $\phi$ is similar to a completely contractive map $\phi'$. Motivated by ... More
Critical control of a genetic algorithmMay 19 2010Based on speculations coming from statistical mechanics and the conjectured existence of critical states, I propose a simple heuristic in order to control the mutation probability and the population size of a genetic algorithm.
Spectral and homological properties of Hilbert modules over the disc algebraJul 19 2013May 22 2014We study general Hilbert modules over the disc algebra and exhibit necessary spectral conditions for the vanishing of certain associated extension groups. In particular, this sheds some light on the problem of identifying the projective Hilbert modules. ... More
Critical population and error threshold on the sharp peak landscape for a Moran modelMay 15 2012Oct 23 2012The goal of this work is to propose a finite population counterpart to Eigen's model, which incorporates stochastic effects. We consider a Moran model describing the evolution of a population of size $m$ of chromosomes of length $\ell$ over an alphabet ... More
$J$-invariant of hermitian formsFeb 12 2016Oct 01 2016We develop the version of the $J$-invariant for hermitian forms in a similar way Alexander Vishik did it for quadratic forms. This discrete invariant contains informations about rationality of algebraic cycles on the maximal unitary grassmannian associated ... More
Network of BanditsFeb 11 2016Oct 11 2016The distribution of machine learning tasks on the user's devices offers several advantages for application purposes: scalability, reduction of deployment costs and privacy. We propose a basic brick, Distributed Median Elimination, which can be used to ... More
Spectral instability of some non-selfadjoint anharmonic oscillatorsJan 22 2013The purpose of this Note is to highlight the spectral instability of some non-selfadjoint differential operators, by studying the growth rate of the norms of the spectral projections $\Pi_n$ associated with their eigenvalues. More precisely, we are concerned ... More
The travel time in a finite box in supercritical Bernoulli percolationJul 11 2013We consider the standard site percolation model on the three dimensional cubic lattice. Starting solely with the hypothesis that $\theta(p)>0$, we prove that, for any $\alpha>0$, there exists $\kappa>0$ such that, with probability larger than $1-1/n^\alpha$, ... More
Non-compact form of the Elementary Discrete InvariantDec 18 2017Sep 05 2018We determine the non-compact form of Vishik's Elementary Discrete Invariant for quadrics. As an application, we obtain new restrictions on the possible values of the Elementary Discrete Invariant by studying the action of Steenrod operations on the algebraic ... More
Picard group of the forms of the affine line and of the additive groupOct 07 2016Nov 21 2016We obtain an explicit upper bound on the torsion of the Picard group of the forms of the affine line and their regular completions. We also obtain a sufficient condition for the Picard group of the forms of the affine line to be non trivial and we give ... More
On the parallel transport in quantum mechanics with an application to three-state systemsMar 11 2019The aim of this article is to give a rigorous although simple treatment of the geometric notions around parallel transport in quantum mechanics. I start by defining the teleparallelism (or generalized Pancharatnam connection) between n-dimensional vector ... More
Quasiaffine orbits of invariant subspaces for uniform Jordan operatorsAug 27 2011May 22 2014We consider the problem of classification of invariant subspaces for the class of uniform Jordan operators. We show that given two invariant subspaces $M_1$ and $M_2$ of a uniform Jordan operator $T=S(\theta)\oplus S(\theta)\oplus \ldots$, the subspace ... More
The stepping stone model in a random environment and the effect of local heterogneities on isolation by distance patternsJul 06 2018Jun 13 2019We study a one-dimensional spatial population model where the population sizes at each site are chosen according to a translation invariant and ergodic distribution and are uniformly bounded away from 0 and infinity. We suppose that the frequencies of ... More
Around rationality of integral cyclesMar 12 2012In this article we prove a result comparing rationality of integral algebraic cycles over the function field of a quadric and over the base field. This is an integral version of the result known for coefficients modulo 2. Those results have already been ... More
On quantitative noise stability and influences for discrete and continuous modelsJan 28 2014Nov 12 2014In [K-K], Keller and Kindler proved a quantitative version of the famous Benjamini - Kalai-Schramm Theorem on noise sensitiviy of Boolean funtions. The result was extented to the continuous Gaussian setting in [K-M-S2] by means of a Central Limit Theorem ... More
Remarks on the lifespan of the solutions to some models of incompressible fluid mechanicsJan 30 2012We give lower bounds for the lifespan of a solution to the inviscid Boussinesq system. In dimension two, we point out that it tends to infinity when the initial (relative) temperature tends to zero. This is, to the best of our knowledge, the first result ... More
A lower bound on the two-arms exponent for critical percolation on the latticeJun 13 2013Oct 29 2015We consider the standard site percolation model on the $d$-dimensional lattice. A direct consequence of the proof of the uniqueness of the infinite cluster of Aizenman, Kesten and Newman [Comm. Math. Phys. 111 (1987) 505-531] is that the two-arms exponent ... More
Parallelizing Stream with FutureMay 19 2013Stream is re-interpreted in terms of a Lazy monad. Future is substituted for Lazy in the obtained construct, resulting in possible parallelization of any algorithm expressible as a Stream computation. The principle is tested against two example algorithms. ... More
Critical population and error threshold on the sharp peak landscape for the Wright-Fisher modelJul 03 2012Jun 19 2015We pursue the task of developing a finite population counterpart to Eigen's model. We consider the classical Wright-Fisher model describing the evolution of a population of size $m$ of chromosomes of length $\ell$ over an alphabet of cardinality $\kappa$. ... More
On the unilateral shift as a Hilbert module over the disc algebraFeb 25 2013May 22 2014We study the unilateral shift (of arbitrary countable multiplicity) as a Hilbert module over the disc algebra and the associated extension groups. In relation with the problem of determining whether this module is projective, we consider a special class ... More
Automizers as extended reflection groupsOct 21 2010Brou\'e, Malle and Michel have shown that the automizer of an abelian Sylow p-subgroup in a finite simple Chevalley group is an irreducible complex reflection group, for p not too small and different from the defining characteristic. The aim is this note ... More
Spectral instability for even non-selfadjoint anharmonic oscillatorsJan 22 2013Oct 17 2013We study the instability of the spectrum for a class of non-selfadjoint anharmonic oscillators, estimating the behavior of the instability indices (i. e. the norm of spectral projections) associated with the large eigenvalues of these oscillators. We ... More
Threshold for monotone symmetric properties through a logarithmic Sobolev inequalityNov 24 2005Nov 20 2006Threshold phenomena are investigated using a general approach, following Talagrand [Ann. Probab. 22 (1994) 1576--1587] and Friedgut and Kalai [Proc. Amer. Math. Soc. 12 (1999) 1017--1054]. The general upper bound for the threshold width of symmetric monotone ... More
The largest root of random Kac polynomials is heavy tailedApr 10 2017We prove that the largest and smallest root in modulus of random Kac polynomials have a non-universal behavior. They do not converge towards the edge of the support of the limiting distribution of the zeros. This non-universality is surprising as the ... More
The quasispecies regime for the simple genetic algorithm with roulette-wheel selectionJun 30 2015Dec 03 2015We introduce a new parameter to discuss the behavior of a genetic algorithm. This parameter is the mean number of exact copies of the best fit chromosomes from one generation to the next. We argue that the genetic algorithm should operate efficiently ... More
Unitary equivalence and similarity to Jordan models for weak contractions of class $C_0$Jun 14 2013May 22 2014We obtain results on the unitary equivalence of weak contractions of class $C_0$ to their Jordan models under an assumption on their commutants. In particular, our work addresses the case of arbitrary finite multiplicity. The main tool is the theory of ... More
The quasispecies regime for the simple genetic algorithm with ranking selectionMar 21 2014We study the simple genetic algorithm with a ranking selection mechanism (linear ranking or tournament). We denote by $\ell$ the length of the chromosomes, by $m$ the population size, by $p_C$ the crossover probability and by $p_M$ the mutation probability. ... More
Khovanov-Rozansky homology and 2-braid groupsMar 22 2012Khovanov has given a construction of the Khovanov-Rozansky link invariants (categorifying the HOMFLYPT invariant) using Hochschild cohomology of 2-braid groups. We give a direct proof that his construction does give link invariants. We show more generally ... More
Picard group of the forms of the affine line and of the additive groupOct 07 2016We obtain an explicit upper bound on the torsion of the Picard group of the forms of the affine line and of the additive group, and a sufficient condition for this Picard group to be non trivial. We also give examples of non trivial forms of the affine ... More
Modell zur Entstehung eines Rings aus Dunkler Materie in der MilchstraßenebeneOct 29 2008Jan 15 2010Both the distribution of hydrogen and the rotation curve of the Milky Way indicate the existence of a ring of Cold Dark Matter in the galactic plane with a radius of 14 kiloparsecs around the galactic centre. Using a semianalytical model, the formation ... More
Symmetric correspondences on quadricsNov 14 2016We prove a result comparing the rationality of some elementary algebraic cycles introduced by Alexander Vishik, defined on orthogonal grassmannians, with the rationality of some algebraic cycles defined on fiber products of the corresponding quadric.
Soliton resolution for equivariant wave maps to the sphereMay 23 2013We consider finite energy corotationnal wave maps with target manifold $\m S^2$. We prove that for a sequence of times, they decompose as a sum of decoupled harmonic maps in the light cone, and a smooth wave map (in the blow case) or a linear scattering ... More
The stepping stone model in a random environment and the effect of local heterogneities on isolation by distance patternsJul 06 2018We study a one-dimensional spatial population model where the population sizes at each site are chosen according to a translation invariant and ergodic distribution and are uniformly bounded away from 0 and infinity. We suppose that the frequencies of ... More
Quasisimilarity of invariant subspaces for $C_0$ operators with multiplicity twoSep 17 2011May 22 2014For an operator $T$ of class $C_0$ with multiplicity two, we show that the quasisimilarity class of an invariant subspace $M$ is determined by the quasisimilarity classes of the restriction $T|M$ and of the compression $T_{M^\perp}$. We also provide a ... More
A Twisted Fourth Moment of Dirichlet L-functionsNov 29 2016We evaluate some twisted fourth moment of Dirichlet $L$-functions at the central point s=1/2 and for prime moduli q. The principal tool is a careful analysis of a shifted convolution problem involving the divisor function using spectral theory of automorphic ... More
On the well-posedness of the incompressible density-dependent Euler equations in the $L^p$ frameworkJul 23 2009The present paper is devoted to the study of the well-posedness issue for the density-dependent Euler equations in the whole space. We establish local-in-time results for the Cauchy problem pertaining to data in the Besov spaces embedded in the set of ... More
Non-commutative peaking phenomena and a local version of the hyperrigidity conjectureSep 06 2017Feb 28 2018We investigate various notions of peaking behaviour for states on a $\mathrm{C}^*$-algebra, where the peaking occurs within an operator system. We pay particularly close attention to the existence of sequences of elements forming an approximation of the ... More
On the divergence of Birkhoff Normal FormsJun 03 2019It is well known that a real analytic symplectic diffeomorphism of the two-dimensional annulus admitting a real analytic invariant curve with diophantine rotation number can be {\it formally} conjugated to its Birkhoff Normal Form, a formal power series ... More
An unified approach to the Junta theorem for discrete and continuous modelsFeb 02 2017In a recent paper, T. Austin has proved an analogous theorem for the continuous torus of the original Junta theorem proved by Friedgut in the case of the Boolean cube. Analogous statements have been established recently in discrete cases such as the discrete ... More
Network of Bandits insure Privacy of end-usersFeb 11 2016Mar 29 2017In order to distribute the best arm identification task as close as possible to the user's devices, on the edge of the Radio Access Network, we propose a new problem setting, where distributed players collaborate to find the best arm. This architecture ... More
Fourier analysis methods for the compressible Navier-Stokes equationsJul 09 2015In the last three decades, Fourier analysis methods have known a growing importance in the study of linear and nonlinear PDE's. In particular, techniques based on Littlewood-Paley decomposition and paradifferential calculus have proved to be very efficient ... More
Similarity results for operators of class C_0Apr 01 2011Oct 05 2011If T is a multiplicity-free contraction of class C_0 with minimal function m_T, then it is quasisimilar to the Jordan block S(m_T). In case m_T is a Blaschke product with simple roots forming a Carleson sequence, we show that the relation between T and ... More
Scaling limit of dynamical percolation on critical Erdös-Rényi random graphsOct 25 2017Jun 22 2018Consider a critical Erd\"os-R\'enyi random graph: $n$ is the number of vertices, each one of the $\binom{n}{2}$ possible edges is kept in the graph independently from the others with probability $n^{-1}+\lambda n^{-4/3}$, $\lambda$ being a fixed real ... More
On the irreducibility of Deligne-Lusztig varietiesJan 16 2006Apr 12 2006Let $G$ be a connected reductive algebraic group defined over an algebraic closure of a finite field and let $F : G \to G$ be an endomorphism such that $F^d$ is a Frobenius endomorphism for some $d \geq 1$. Let $P$ be a parabolic subgroup of $G$ admitting ... More
Convergence of a stochastic particle approximation for fractional scalar conservation lawsJun 21 2010We give a probabilistic numerical method for solving a partial differential equation with fractional diffusion and nonlinear drift. The probabilistic interpretation of this equation uses a system of particles driven by L\'evy alpha-stable processes and ... More
Endoscopie et conjecture raffinée de Gan-Gross-Prasad pour les groupes unitairesDec 05 2012Mar 29 2014Under endoscopic assumptions about $L$-packets of unitary groups, we prove the local Gan-Gross-Prasad conjecture for tempered representations of unitary groups over $p$-adic fields. Roughly, this conjecture says that branching laws for $U(n-1)\subset ... More
Construction of a multi-soliton blow-up solution to the semilinear wave equation in one space dimensionOct 11 2011Apr 24 2012We consider the semilinear wave equation with power nonlinearity in one space dimension. Given a blow-up solution with a characteristic point, we refine the blow-up behavior first derived by Merle and Zaag. We also refine the geometry of the blow-up set ... More
A local trace formula for the Gan-Gross-Prasad conjecture for unitary groups: the archimedean caseJun 04 2015Dec 21 2015In this paper, we prove, following earlier work of Waldspurger ([Wa1], [Wa4]), a sort of local relative trace formula which is related to the local Gan-Gross-Prasad conjecture for unitary groups over a local field $F$ of characteristic zero. As a consequence, ... More
Lower large deviations for the maximal flow through a domain of $\mathbb{R}^d$ in first passage percolationJul 31 2009We consider the standard first passage percolation model in the rescaled graph $\mathbb{Z}^d/n$ for $d\geq 2$, and a domain $\Omega$ of boundary $\Gamma$ in $\mathbb{R}^d$. Let $\Gamma^1$ and $\Gamma^2$ be two disjoint open subsets of $\Gamma$, representing ... More
Weak shape theorem in first passage percolation with infinite passage timesApr 17 2014Nov 20 2014We consider the model of i.i.d. first passage percolation on $\mathbb{Z}^d$ : we associate with each edge $e$ of the graph a passage time $t(e)$ taking values in $[0,+\infty]$, such that $\mathbb{P}[t(e)<+\infty] >p_c(d)$. Equivalently, we consider a ... More
Multiplier algebras of complete Nevanlinna-Pick spaces: dilations, boundary representations and hyperrigidityDec 12 2016Oct 20 2017We study reproducing kernel Hilbert spaces on the unit ball with the complete Nevanlinna-Pick property through the representation theory of their algebras of multipliers. We give a complete description of the representations in terms of the reproducing ... More
Towards an ultra efficient kinetic scheme Part II: The high order caseDec 02 2012In a recent paper we presented a new ultra efficient numerical method for solving kinetic equations of the Boltzmann type (G. Dimarco, R. Loubere, Towards an ultra efficient kinetic scheme. Part I: basics on the 689 BGK equation, J. Comp. Phys., (2013), ... More
A probabilistic representation of the quasispecies distributionJul 05 2016We give a probabilistic representation of the stationary solutions of Eigen's model, when the set of possible genotypes is finite and the mutation matrix is primitive. In the long chain regime, we perform a formal passage to the limit to obtain a probabilistic ... More
Bicovariograms and Euler characteristic II. Random fields excursionsOct 02 2015Dec 09 2015Let f be a C1 bivariate function with Lipschitz derivatives, and F its level set at elvel lambda. We give an expression of the Euler characteristic of F in terms of the three-points indicator functions of the set. If f is a two-dimensional C1 random field ... More
Multi-armed Bandit Problem with Known TrendAug 28 2015Mar 02 2016We consider a variant of the multi-armed bandit model, which we call multi-armed bandit problem with known trend, where the gambler knows the shape of the reward function of each arm but not its distribution. This new problem is motivated by different ... More
Multi-solitons for nonlinear Klein-Gordon equationsOct 30 2012Oct 01 2013In this paper we consider the existence of multi-soliton structures for the nonlinear Klein-Gordon equation (NLKG) in R^{1+d}. We prove that, independently of the unstable character of (NLKG) solitons, it is possible to construct a N-soliton family of ... More
A Curie-Weiss model of self-organized criticalityJan 29 2013Feb 09 2016We try to design a simple model exhibiting self-organized criticality, which is amenable to a rigorous mathematical analysis. To this end, we modify the generalized Ising Curie-Weiss model by implementing an automatic control of the inverse temperature. ... More
Expression d'un facteur epsilon de paire par une formule intégraleDec 05 2012Let $E/F$ be a quadratic extension of $p$-adic fields and let $d$, $m$ be nonnegative integers of distinct parities. Fix admissible irreducible tempered representations $\pi$ and $\sigma$ of $GL_d(E)$ and $GL_m(E)$ respectively. We assume that $\pi$ and ... More
La conjecture locale de Gross-Prasad pour les représentations tempérées des groupes unitairesMay 14 2012Dec 04 2012Let $E/F$ be a quadratic extension of non-archimedean local fields of characteristic 0 and let $G=U(n)$, $H=U(m)$ be unitary groups of hermitian spaces $V$ and $W$. Assume that $V$ contains $W$ and that the orthogonal complement of $W$ is a quasisplit ... More
Cellules de Calogero-MoserFeb 12 2013Using the representation theory of Cherednik algebras at t=0 and a Galois covering of the Calogero-Moser space, we define the notions of left, right and two-sided Calogero-Moser cells for any finite complex reflection group. To each Caloger-Moser two-sided ... More
Calogero-Moser versus Kazhdan-Lusztig cellsJan 03 2012In 1979, Kazhdan and Lusztig developed a combinatorial theory associated with Coxeter groups. They defined in particular partitions of the group in left and two-sided cells. In 1983, Lusztig generalized this theory to Hecke algebras of Coxeter groups ... More
Compactification des variétés de Deligne-LusztigJan 10 2008Sep 04 2008We construct explicitly the normalisation of the Bott-Samelson-Demazure-Hansen compactification of Deligne-Lusztig varieties $X(w)$ in their covering $Y(w)$: we retrieve a result by Deligne-Lusztig about the local monodromy around the divisors of the ... More
Smooth type II blow up solutions to the four dimensional energy critical wave equationOct 08 2010We exhibit $\mathcal C^{\infty}$ type II blow up solutions to the focusing energy critical wave equation in dimension $N=4$. These solutions admit near blow up time a decomposiiton $u(t,x)=1/l(t)(Q+e(t))(x/l(t)}}$ with $|e(t),\pa_t e(t)|_{\dot{H}^1\times ... More
Merging diabolical points of a superconducting circuitNov 15 2011Sep 25 2013We present the first theoretical study of the merging of diabolical points in the context of superconducting circuits. We begin by studying an analytically solvable four-level model which may serve as theoretical pattern for such a phenomenon. Then, we ... More
On the well-posedness of the full low-Mach number limit system in general critical Besov spacesJan 31 2012This work is devoted to the well-posedness issue for the low-Mach number limit system obtained from the full compressible Navier-Stokes system, in the whole space. In the case where the initial temperature (or density) is close to a positive constant, ... More
Topical Community Detection in Event-based Social NetworkMar 12 2018Event-based services have recently witnessed a rapid growth driving the way people explore and share information of interest. They host a huge amount of users' activities including explicit RSVP, shared photos, comments and social connections. Exploiting ... More
Existence and continuity of the flow constant in first passage percolationJul 27 2017Sep 24 2018We consider the model of i.i.d. first passage percolation on Z^d, where we associate with the edges of the graph a family of i.i.d. random variables with common distribution G on [0, +$\infty$] (including +$\infty$). Whereas the time constant is associated ... More
Cherednik algebras and Calogero-Moser cellsAug 31 2017Sep 07 2017Using the representation theory of Cherednik algebras at $t=0$ and a Galois covering of the Calogero-Moser space, we define the notions of left, right and two-sided Calogero-Moser cells for any finite complex reflection group. To each Caloger-Moser two-sided ... More
On the persistence of Hölder regular patches of density for the inhomogeneous Navier-Stokes equationsDec 01 2016In our recent work dedicated to the Boussinesq equations [Danchin and Zhang 2016], we established the persistence of solutions with piecewise constant temperature along interfaces with H\"older regularity. We here address the same problem for the inhomogeneous ... More
The quasispecies distributionSep 19 2016The quasispecies model was introduced in 1971 by Manfred Eigen to discuss the first stages of life on Earth. It provides an appealing mathematical framework to study the evolution of populations in biology, for instance viruses. We present briefly the ... More
Spectral analysis of a complex Schrödinger operator in the semiclassical limitOct 23 2015Jun 27 2016We consider the Dirichlet realization of the operator $-h^2\Delta+iV$ in the semi-classical limit $h\to0$, where $V$ is a smooth real potential with no critical points. For a one dimensional setting, we obtain the complete asymptotic expansion, in powers ... More
Plancherel formula for $\mathrm{GL}_n(F)\backslash \mathrm{GL}_n(E)$ and applications to the Ichino-Ikeda and formal degree conjectures for unitary groupsNov 30 2018We establish an explicit Plancherel decomposition for $\mathrm{GL}_n(F)\backslash \mathrm{GL}_n(E)$ where $E/F$ is a quadratic extension of local fields of characteristic zero by making use of a local functional equation for Asai $\gamma$-factors. We ... More
Runtime Enforcement With Partial ControlAug 26 2015This study carries forward the line of enquiry that seeks to characterize precisely which security policies are enforceable by runtime monitors. In this regard, Basin et al.\ recently refined the structure that helps distinguish between those actions ... More
Multi-armed Bandit Problem with Known TrendAug 28 2015May 10 2017We consider a variant of the multi-armed bandit model, which we call multi-armed bandit problem with known trend, where the gambler knows the shape of the reward function of each arm but not its distribution. This new problem is motivated by different ... More
Classical Noether's theory with application to the linearly damped particleDec 23 2014May 12 2015This paper provides a modern presentation of Noether's theory in the realm of classical dynamics, with application to the problem of a particle submitted to both a potential and a linear dissipation. After a review of the close relationships between Noether ... More
Symmetry Preserving Numerical Schemes for Partial Differential Equations and their Numerical TestsOct 26 2011The method of equivariant moving frames on multi-space is used to construct symmetry preserving finite difference schemes of partial differential equations invariant under finite-dimensional symmetry groups. Invariant numerical schemes for a heat equation ... More
Cramér's theorem for asymptotically decoupled fieldsMar 22 2011We give a general setting for Cram\'er's large deviations theorem for the empirical means of a field of random vectors, which contains Cram\'er's theorem for i.i.d. random vectors and Sanov's theorem for asymptotically decoupled measures. ----- Nous \'etablissons ... More