Quantum ergodicity deals with the (de)localization of eigenfunctions of Schrödinger operators, for classically chaotic systems. In this talk I will review the rigourous results on the subject. I will also talk about my recent work with Etienne Le Masson, where we studied the delocalization of eigenfunctions on large regular (discrete) graphs.

Departement de Mathématiques, Univ. d’Orsay