Supercritical Chaos

When: Friday, March 5, 2021, 4:30 PM - 4:30 PM
Where: ,

Speaker: Cillian Cockrell

Abstract: Many-body Hamiltonian systems, the subject of classical statistical mechanics, are well known to exhibit the features of dynamical chaos. One of these features is dynamical instability – an exponential divergence of neighbouring points in phase space under the dynamical evolution. 

Abstract: Many-body Hamiltonian systems, the subject of classical statistical mechanics, are well known to exhibit the features of dynamical chaos. One of these features is dynamical instability – an exponential divergence of neighbouring points in phase space under the dynamical evolution. In other words, in chaotic systems “the present determines the future but the approximate present does not approximately determine the future”. We often see phases such as solid and liquid as macroscopic notions, derived from thermodynamics, but the surprising fact is that the dynamical instability of a classical many-body system is sensitive to its macroscopic phase. In this talk I will talk about the definitions of chaos and their implications for problems in classical statistical mechanics, describe how we can measure the dynamical instability of classical systems using molecular dynamics simulations, how it is affected by the melting phase transition, and my recent extension of this work into the supercritical fluid phase.