Stability and Instability of Relativistic Fluids in Slowly Expanding Spacetimes

Explore a physics seminar from the Harvard CMSA General Relativity series examining the stability characteristics of relativistic fluids in expanding spacetimes. Delve into the fascinating transition between stable and unstable behavior of homogeneous and isotropic solutions to relativistic Euler equations across different spacetime backgrounds. Learn how these solutions, known to be unstable in Minkowski space, achieve stability in FLRW models with rapid expansion rates. Through analytical results and numerical analysis, investigate this phase transition phenomenon across various equations of state, with particular emphasis on linear and decelerated expansion scenarios. Gain insights from University of Vienna researcher Maximilian Ofner's examination of how expansion rates parametrize stability behavior in relativistic fluid dynamics.