Abstract
This seminar examined the various problems for which the renormalization group can be implemented in the case of highly disordered systems : chains of disordered quantum spins, Sinai scattering, domain growth in the presence or absence of disorder. The central idea behind the renormalization approach to all these problems is quite similar to the original idea of Kadanoff blocks : in real space, spins coupled by the strongest interactions are grouped together in the case of spin chains ; the lowest barriers are eliminated in Sinai scattering, and the smallest domains are eliminated in the case of domain growth.
