Nicki Mullins

University of Illinois Urbana-Champaign, December 8, 12:00 pm

Stochastic fluctuations in relativistic fluids: causality, stability, and the information current

The study of the quark-gluon plasma in high-energy nuclear physics has generated significant research into relativistic fluid dynamics. While hydrodynamic simulations have been used to model various phenomena in heavy-ion collisions, the commonly used formulations are incomplete, as they are inconsistent with basic thermodynamic principles. In particular, they lack the thermal fluctuations necessary to ensure the system realizes the correct equilibrium distribution. In this talk, I will discuss a new means of modeling thermal fluctuations in relativistic systems that ensure that the correlators are independent of the choice of spacetime foliation. This formulation is constructed using the recently developed information current, which is instrumental when studying causality and stability in relativistic systems. By using the information current to describe fluctuations, this formulation builds constraints associated with these effects directly into the modeling. Using this new method of describing fluctuating relativistic systems, we will construct an effective action and show that a fluctuation-dissipation relation can be realized in this action through a symmetry associated with detailed balance.