1. ergodic and non-ergodic many-body dynamics in strongly nonlinear lattices

Remy Dubertrand

University of Northumbria, UK

7 January 2021 Thu 5 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

The study of non-linear oscillator chains in classical many-body dynamics has a storied history going back to the seminal work of Fermi, Pasta, Ulam and Tsingou (FPUT). We introduce a new family of such systems which consist of chains of N harmonically coupled particles with the non-linearity introduced by confining the motion of each individual particle to a box with hard walls.

The boxes are arranged on a one-dimensional lattice, but they individually do not have to be one-dimensional thus permitting the introduction of chaos already at the lattice scale.

In this webinar I will describe our first results about the model and discuss their consequences. When the boxes are one-dimensional, the phase space of the chain is mixed for any finite value of N. The continuum limit appears as a singular limit of sinh Gordon. When the boxes are two-dimensional Bunimovich stadia, we found a more chaotic phase space at small system sizes.