Tri-séminaire de Physique Statistique : Matthieu Wyart

Quand

02/07/2015    
14:30 - 16:00

LPTMS, salle 201, 2ème étage, Bât 100, Campus d'Orsay
15 Rue Georges Clemenceau, Orsay, 91405

Type d’évènement

Chargement de la carte…

Marginal stability and flow in granular materials

Matthieu WYART (New York University)

Complex systems are characterized by an abundance of meta-stable states.This is the case for granular materials, that can flow until one jammed configuration (among the exponentially many possible ones) is reached. I will argue that at least in popular simplified models of granular materials, these dynamically-accessible configurations are stable, but barely so. Such marginal stability offers a new perspective on both the solid and the liquid phase. I will discuss dense suspensions and propose to describe flow as a gas of elementary excitations, corresponding to the opening and closing of contact between particles. This approach leads to a detailed scaling description of rheological properties and length scales of dense flows. If time permits I will discuss a classification of athermal glassy systems based on the stability of low-energy excitations.

Retour en haut