Title: Hydrodynamic fluctuations and lower bounds of the transport coefficients
Abstract: In this talk I will discuss the effects of hydrodynamic fluctuations in non-relativistic and relativistic setups. Within the framework of stochastic hydrodynamics I obtain a number of model independent results, including the long-time tail of different transport coefficients, and the leading non-analyticity of the correlators of energy, momentum and particle density in non-relativistic and relativistic setups. The presence of hydrodynamic fluctuations induce lower bounds on the transport coefficients by analyzing the low frequency limit of different correlation functions. I determine the lower bounds of the bulk viscosity over entropy ratio in a cold Fermi gas near unitarity. When extending this analysis to the case of a U(1) conformal relativistic expanding fluid we observe that the values of the shear viscosity and heat conductivity are bounded from below. In both setups, non-relativistic and relativistic one, the lower bounds on the transport coefficients are weakly dependent on assumptions regarding the range of applicability of fluid dynamics.
HEP Oct31 Martinez Guerrero flyer