Abstract
Dynamics of Cosmological Fluids in the Critical Regime of Slow Expansion
Homogeneous and isotropic solutions to the relativistic Euler equations are known to be unstable on a Minkowski background. However, for FLRW models with a fast expansion rate, relativistic fluids stabilize. This scenario suggests a transition between stable and unstable behavior, somewhere along a family of spacetimes parametrized by their expansion rate. In this talk, we give a short overview of the results of the present thesis. They comprise a set of theorems regarding the stability properties of solutions to the relativistic Euler equations as well as the Einstein-Euler system near a hypothesized transition line. In particular, the fully coupled problem is analyzed in the regime of linear expansion, while fluids on a fixed background are examined in the decelerated region.
Defense committee:
Juan A. Valiente-Kroon, Queen Mary University of London, UK (reviewer)
Mahir Hadžić, Universtiy College London, UK (reviewer)
David Fajman (supervisor)
Thomas Pichler (chair)