Hydrodynamics as v s → c

Abstract

Abstract I present the simplest 3+1 dimensional quantum field theory for which the speed of sound can be arbitrarily close to the speed of light. Examining the hydrodynamics, I find cases where the shear viscosity is finite, but the “shear relaxation coefficient” appears always to be divergently large.

Keywords

• Thermal Field Theory
• Field Theory Hydrodynamics
• Non-Equilibrium Field Theory