UNC-CH Physics and Astronomy Master’s Presentation

Shuo Song

“Thermal Fluctuations in Relativistic Hydrodynamics”

The theory of hydrodynamics has made lots of success in the past, but the full potential of the theory has not been reached yet. Relativistic hydrodynamics received increasing attentions in recent years, and one of the reasons is that it can describe the evolution of quark-gluon plasma in heavy ion collisions. A missing ingredient in the theory of hydrodynamics is fluctuations, which were ignored due to their negligible effects under the presence of large degrees of freedom. But for systems containing hundreds or thousands of particles like the ones encountered in heavy ion collisions, the degrees of freedom are large enough for hydrodynamics to be valid, yet small enough for fluctuations to be important. Fluctuations are further enhanced near the critical point due to the increase of correlation length. Thus, studying hydrodynamic fluctuations is necessary to find the full potential of this classical theory. In this presentation, I will first review some well-established theories of fluctuations in equilibrium and non-equilibrium thermodynamics, both from the stochastic approach and the effective field theory approach. Then I will introduce some recent advances in hydrodynamic fluctuations and how we can use it to search and to extend the theory around the QCD critical point.