Seminars & Colloquia Calendar
Renormalization and disorder : a simple toy model
Bernard Derrida - Ecole Normale Supérieure de Paris
Date & time: Wednesday, 06 October 2021 at 10:45AM - 11:45AM
After a short review of our understanding of how a weak disorder or a low density of impurities affect the universality class of a phase transition, I will discuss a simple tree-like toy model for which one can prove that, due to disorder, the depinning transition becomes an infinite order transition of the Berezinski-Kosterlitz-Thouless type. This toy model was introduced to understand the depinning transition of a line from a random substrate, one of the simplest problems in the theory of disordered systems. This depinning transition has a long history among physicists and mathematicians. Still the nature of the transition, one of the central questions of the problem, remains unsolved.