Séminaire: Problèmes Spectraux en Physique Mathématique


Année 2017-2018



Les séminaires auront lieu à l'Institut Henri Poincaré, habituellement en salle 314.
Le séminaire est financé par le GDR "Dynamique quantique" du CNRS.

Pour tout renseignement complémentaire, veuillez contacter les organisateurs, Hakim Boumaza, Mathieu Lewin ou Stéphane Nonnenmacher.

Prochain séminaire le lundi 11 juin 2018 en salle 314 (3e étage)
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 11h15 - 12h15 Rémy Rhodes (Paris-Est)
Liouville quantum theory and the DOZZ formula

Abstract:
This talk will review some recent advances in the study of the Liouville quantum theory. This theory was introduced in physics by Polyakov in 1981 in the context of string theory. This is a conformal field theory based on a path integral à la Feynman and it can be seen as the natural extension of the theory of Riemann surfaces to the probabilistic framework. Solving this theory, namely computing the correlation functions, has been a great challenge in physics. In this direction and in the 90s, Dorn-Otto and the Zamolodchikov brothers conjectured that the 3-point correlation function satisfies a mysterious formula based on number theory, called the DOZZ formula.
The main purpose of this talk is to explain this story and to present the construction of the path integral for the Liouville quantum theory. Then I will explain the DOZZ formula. Time depending, I will finally discuss how computing all other correlation functions reduces to DOZZ and to the spectral problem associated to the Hamiltonian of the Liouville theory.
Based on works with F. David, A. Kupiainen and V. Vargas.

Déjeuner
14h - 15h Alexander Adam (Jussieu)
Horocycle averages on closed manifolds

Abstract:
A well-known example of a contact Anosov flow is the geodesic flow on the unit tangent bundle SX of a closed Riemannian manifold X with variable negative sectional curvature. SX is foliated by the stable manifolds, on which one defines the horocycle flow. This flow is uniquely ergodic.
What is the speed of convergence to the Birkhoff averages ?
In 2003 Flaminio and Forni investigated this question in the case of constant negative curvature. They found that the speed of convergence is controlled by the existence of distributions which are invariant w.r.to the horocycle flow. These distributions are also eigendistributions of the
geodesic flow. The speed of convergence is then determined by a (fractional) power spectrum, with exponents associated to those eigenvalues.

I will report on this phenomenon for contact Anosov flows of sufficient regularity.
 15h15 - 16h15 Maurizia Rossi (Paris 5)
Asymptotic distribution of nodal intersections for arithmetic random waves

Abstract:
We focus on the nodal intersection number of random Gaussian toral Laplace eigenfunctions ("arithmetic random waves") against a fixed smooth reference curve. The expected intersection number is proportional to the the square root of the eigenvalue times the length of curve, independently of its geometry. The asymptotic behaviour of the variance was addressed by Rudnick-Wigman; they found a precise asymptotic law for "generic" curves with nowhere vanishing curvature, depending on both its geometry and the angular distribution of lattice points lying on the circles corresponding to the Laplace eigenvalues. They also discovered that there exist peculiar "static" curves, with variances of smaller order of magnitude, though did not describe the asymptotic behaviourn in this case.
In this talk we investigate the finer aspects of the limit distribution of the nodal intersections number. For generic curves we prove a Central Limit Theorem (for most of the energies). For the aforementioned static curves, we establish a non-Gaussian limit theorem for the distribution of the nodal intersections, and obtain the asymptotic behaviour of their fluctuations, under a well-separatedness assumption on the corresponding lattice points, satisfied by most of the
eigenvalues.
This is a joint work with Igor Wigman.


Prochaines dates prévues:

octobre 2018:

Informations pratiques: Plan d'accès à l'IHP.

Historique du séminaire:

Année 2017-2018
Année 2016-2017
Année 2015-2016
Année 2014-2015
Année 2013-2014
Année 2012-2013
Année 2011-2012
Année 2010-2011
Année 2009-2010
Année 2008-2009
Année 2007-2008
Année 2006-2007
Année 2005-2006

Dernière mise à jour: 30 mai 2018
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