## Approche universelle à la localisation des ondes stationnaires

Type:
Site:
Date:
11/01/2018 - 15:00 - 16:00
Salle:
P1 P15
Orateur:
FILOCHE Marcel
Localisation:
École polytechnique
Localisation:
France

## Potentials, energies and Hausdorff dimension

Type:
Site:
Date:
11/01/2018 - 13:45 - 14:45
Salle:
P1 P15
Orateur:
Localisation:
Université de Lund
Localisation:
Suède
Résumé:

There is a classical connection between Riesz-potentials, Riesz-energies and Hausdorff dimension. Otto Frostman (Lund) proved in his thesis that if $E$ is a set and $\mu$ is a measure with support in $E$, then the Hausdorff dimension of $E$ is at least $s$ if the $s$-dimensional Riesz-energy of $\mu$ is finite. I will first recall Frostman’s result and some of its applications. I will then mention some new methods where Hausdorff dimension is calculated using potentials and energies with inhomogeneous kernels. Some applications are in stochastic geometry and dynamical systems.

## Sommes ergodiques de fonctions BV au-dessus d'une rotation

Type:
Site:
Date:
11/01/2018 - 11:00 - 12:00
Salle:
P1 P15
Orateur:
CONZE Jean-Pierre
Localisation:
Université Rennes 1
Localisation:
France

## Une modélisation des disques d'accrétion denses en astrophysique

Type:
Site:
Date:
21/12/2017 - 13:45 - 14:45
Salle:
P1-008
Orateur:
DUCOMET Bernard
Résumé:

Nous proposons dans cet exposé, la dérivation d'un modèle hydrodynamique 2D décrivant un disque d'accrétion en astrophysique à partir de la formulation 3D.
Il s'agit d'une application de la procédure de réduction dimensionnelle introduite récemment par Maltese et Novotny (2014). La méthode revient à utiliser un scaling permettant de passer à la limite dans les équations de Navier-Stokes compressibles et d'identifier deux régimes limites possibles suivant la valeur du nombre de Froude, en introduisant une inégalité d'entropie relative.

## Différents aspects de systèmes dynamiques réels et $p$-adiques

Type:
Type:
Site:
Date:
12/12/2017 - 14:00 - 15:00
Salle:
P1 025
Orateur:
LIAO Lingmin

## RODIAC Rémy

Date:
Lun, 04/12/2017 - Ven, 08/12/2017
Site:
Nom:
RODIAC
Prénom:
Rémy
Origine:
Université catholique de Louvain
Origine:
Belgique
Thème:
Homogénéisation
Invitant:
SANDIER Étienne

## BOUFALA Sonia

Situation:
Permanent
Nom:
BOUFALA
Prénom:
Sonia
Site:
Site:
Statut:
Courriel:
sonia [dot] boufala [at] u-pec [dot] fr
Téléphone:
01 45 17 16 42

## DOBBS Neil

Date:
Mer, 29/11/2017 - Jeu, 07/12/2017
Site:
Nom:
DOBBS
Prénom:
Neil
Origine:
University College Dublin
Origine:
Irlande
Thème:
Système dynamique
Invitant:
MIHALACHE Nicolae

## Theorems and tools in one-dimensional dynamics

Type:
Site:
Date:
06/12/2017 - 13:00 - 15:00
Orateur:
DOBBS Neil
Localisation:
University College Dublin
Localisation:
Irlande
Résumé:

The first lecture will be an accessible introduction (peut-être en français) to smooth one-dimensional dynamics. After some historical examples and results, we shall consider the dynamics of some maps $f_a : x \mapsto ax(1-x)$ from the quadratic family.

In what follows, we shall investigate typical behaviour from the probabilistic viewpoint. In particular, we shall show, under certain conditions, the existence of probability measures which describe the statistical behaviour of Lebesgue almost every orbit. Time permitting, the Markov extension, together with its utility in proving results concerning continuity of statistical properties, will be presented.

## Theorems and tools in one-dimensional dynamics

Type:
Site:
Date:
04/12/2017 - 10:00 - 12:00
Salle:
P1 011
Orateur:
DOBBS Neil
Localisation:
University College Dublin
Localisation:
Irlande
Résumé:

The first lecture will be an accessible introduction (peut-être en français) to smooth one-dimensional dynamics. After some historical examples and results, we shall consider the dynamics of some maps $f_a : x \mapsto ax(1-x)$ from the quadratic family.

In what follows, we shall investigate typical behaviour from the probabilistic viewpoint. In particular, we shall show, under certain conditions, the existence of probability measures which describe the statistical behaviour of Lebesgue almost every orbit. Time permitting, the Markov extension, together with its utility in proving results concerning continuity of statistical properties, will be presented.