Oskar Prośniak – Tuesday 31 March 2026

Speaker: Oskar Prośniak (University of Luxembourg)

Title: Two types of prethermalization in disordered classical systems

Abstract:

Prethermalization may be defined as the parametrically long delay in the relaxation of a large physical system to its thermal state caused by the presence of, possibly several, quasi-conserved quantities. Whenever these quantities form a full set, such a prethermalizing system is said to exhibit asymptotic localization. 
One of the prototypical models exhibiting prethermalization is the non-linear Klein-Gordon chain. When non-disordered, it has been shown to preserve the dressed phonon number up to times polynomial in the nonlinearity strength. When disordered, it is known to exhibit asymptotic localization associated with a super-polynomial conservation of dressed action variables.
We show that in fact both mechanisms are present in the disordered model, as first signalled in Phys. Rev. E 109, 044207 (2024). These two types of prethermalisation are clearly visible at different parameter regimes, while exhibiting interesting interplay in between.