Pierre Le Doussal, lauréat du Prix des Trois Physiciens 2025

Le prix des Trois Physiciens 2025 a été attribué à Pierre Le Doussal pour ses contributions théoriques majeures à la physique des milieux désordonnés, en particulier aux verres de spins, aux réseaux élastiques en présence de désordre et à la prédiction des verres de Bragg, ainsi qu’à ses travaux sur l’équation de Kardar-Parisi-Zhang décrivant la croissance aléatoire des interfaces.

À l’occasion du colloquium de physique du 11 février 2026 du département de physique de l’ENS, qui réunit la communauté des physiciennes et physiciens de l'école, Pierre Le Doussal donne un exposé intitulé : A Tale of Extremes: From Random Growth to Trapped Fermions

A Tale of Extremes: From Random Growth to Trapped Fermions

The Kardar–Parisi–Zhang equation, introduced in 1986, is a paradigmatic model for the random growth of interfaces. It lies at the center of a vast universality class that describes out-of-equilibrium fluctuations in a variety of growth and transport phenomena. It appears ubiquitously, sometimes in mysterious ways, as recently found in quantum spin transport.

I will review recent advances in physics and mathematics that have led to an almost complete characterization of fluctuations in the one-dimensional KPZ class. Surprising connections with random matrix theory have emerged, as well as with the statistics of extreme events.

I will show how a unifying framework based on determinantal point processes naturally emerges and allows one to make predictions in yet another domain of physics: non-interacting cold fermions in traps. Some of these predictions, concerning the spatial organization induced by Pauli’s exclusion principle, have been tested in a recent experiment, which I will describe.