The mixmaster universe is unambiguously chaotic

TL;DR

This paper conclusively demonstrates that the Mixmaster universe exhibits chaotic behavior by identifying a chaotic invariant set within its phase space, resolving longstanding debates.

Contribution

The authors uncover a chaotic invariant set in the Mixmaster phase space and use it to rigorously prove the universe's chaotic dynamics.

Findings

Identification of a chaotic invariant set in the Mixmaster phase space

Proof of the chaotic nature of Mixmaster universe dynamics

Clarification of longstanding debates on chaos in cosmological models

Abstract

The Mixmaster or Bianchi IX cosmological model has become one of the archetypal settings for studying gravitational dynamics. The past decade has seen a vigourous debate about whether or not the Mixmaster's dynamics is chaotic. In this talk we review our recent work in uncovering a chaotic invariant set of orbits in the Mixmaster phase space, and how we used this discovery to prove the dynamics is chaotic.