HAL Paris Dauphine-PSL
Not a member yet
21932 research outputs found
Sort by
Le cédant ne peut invoquer la nullité de la cession en cas de défaut d’agrément d’un tiers étranger dans une SARL
No full textGeneralized Strichartz estimates for the massive Dirac equation with critical potentials
No full textIn this paper we prove generalized Strichartz estimates for the massive Dirac equation in the case of two critical potential perturbations, namely the Aharonov-Bohm magnetic potential and the Coulomb potential. The proof makes use of the relativistic Hankel transform introduced in previous works of Cacciafesta, Séré and Cacciafesta, Fanelli for the massless systems, and here adapted to the massive case: this allows for an explicit representation of the solutions, which reduces the analysis to the proof of suitable estimates on the generalized eigenfunctions of the operators. To the best of our knowledge, these are the first dispersive estimates for the massive Dirac equation with critical potentials
Recognisability Equals Definability for Finitely Representable Matroids of Bounded Path-Width
No full textInternational audienceLet F be a finite field. We prove that there is an MSO-transduction which, given an F-representable matroid of path-width k, produces a branch-decomposition of width at most f(k), for some function f. As a corollary, any recognizable property of F-representable matroids with bounded path-width is definable in MSO logic, and therefore recognizability is equivalent to MSO-definability on classes of F-representable matroids of bounded path-width. This generalizes the result of Bojańczyk, Grohe and Pilipczuk [Logical Methods in Computer Science 17(1), 2021] which asserts the equivalence of the two notions on graphs of bounded linear clique-width
Session spéciale ANR Isovote. Economie et Droit constitutionnel français
No full textInternational audience« L’argument économique et le Conseil constitutionnel », Jérémy Martinez, Université Paris Dauphine-PSL, Centre de recherche Droit Dauphine « Conséquentialisme et délibération constitutionnelle », Sylvie Salles, Laboratoire de recherche en droit - UR 7480 « Le coût de l’inconstitutionnalité », Samuel Ferey, Bureau d’Économie Théorique et Appliquée, Université de Lorrain
On the spectral radius of the ratio of Girko matrices
No full text17 pages, 4 figures, comments are welcome!Girko matrices have independent and identically distributed entries of mean zero and unit variance. In this note, we consider the random matrix model formed by the ratio of two independent Girko matrices, its entries are dependent and heavy-tailed. Our main message is that divided by the square root of the dimension, the spectral radius of the ratio converges in distribution, when the dimension tends to infinity, to a universal heavy-tailed distribution. We provide a mathematical proof of this high-dimensional phenomenon, under a fourth moment matching with a Gaussian case known as the complex Ginibre ensemble. In this Gaussian case, the model is known as the spherical ensemble, and its spectrum is a determinantal planar Coulomb gas. Its image by the inverse stereographic projection is a rotationally invariant gas on the two-sphere. A crucial observation is the invariance in law of the model under inversion, related to its spherical symmetry, and that makes, in a sense, edge and bulk equivalent. Our approach involves Girko Hermitization, local law estimates for Wigner matrices, lower bound estimates on the smallest singular value, and convergence of kernels of determinantal point processes. The universality of the high-dimensional fluctuation of the spectral radius of the ratio of Girko matrices turns out to be remarkably more accessible mathematically than for a single Girko matrix
When Words Save Watts: Government Communication and Household Electricity Use
No full textA central question for policymakers is whether communication can serve as an effective demand-side instrument. This paper studies France’s 2022–23 energy crisis, when reduced nuclear availability and surging prices led the government to launch one of Europe’s largest conservation campaigns. Drawing on more than 12,000 official communications, narrative-specific attention indices from Google searches, and tariff-disaggregated electricity data, the analysis traces the channel from communication to attention to demand. Crisis-framed messages captured attention and reduced consumption, while generic conservation appeals had little effect. Communication thus enhances demand flexibility under scarcity but cannot substitute for prices or operational measures
Sharp exponent of acceleration in general non-local equations with a weak Allee effect
No full textInternational audienceWe study an acceleration phenomenon arising in monostable integro-differential equations with a weak Alleeeffect. Previous works have shown its occurrence and have given correct upper bounds on the rate of expansionin some particular cases, but precise lower bounds were still missing. In this paper, we provide a sharp lowerbound for this acceleration rate, which is valid for a large class of dispersion operators. Our results manage tocover fractional Laplace operators and standard convolutions in a unified way, which is new in the literature. Animportant result of the paper is a general flattening estimate of independent interest: this phenomenon appearsregularly in acceleration situations, but getting quantitative estimates is in general an open question. With thisestimate at hand, we construct a subsolution that captures the expected behaviour of the accelerating solution(rates of expansion and flattening) and identifies several regimes that appear in the dynamics depending on theparameters of the problem
Questionner le bilan des holdings : la Financière Agache et les implications socio-économiques de la naissance de LVMH (1984-1992)
No full textLa menace intérieure : de l'intention à la malveillance
No full textCe séminaire, organisé par l’Institut Cybersécurité Occitanie, s’inscrit dans les initiatives de rencontres interdisciplinaires et intersciences pour tenter de faire émerger un « écosystème de confiance » ouvert aux acteurs, chercheurs, usagers,