Influence of a Critical Point on Hydrodynamic Fluctuations in Heavy Ion Collisions

Hydrodynamic fluctuations have been studied in a wide variety of physical, chemical, and biological phenomena in the past decade. In high energy heavy ion collisions, there will be intrinsic fluctuations even if the initial conditions are fixed. Fluctuations will be greatly enhanced if the trajectory in the plane of temperature versus chemical potential passes near a critical point. We construct a model for the thermal conductivity which diverges at the critical point with the correct critical exponents, and use it in a simple illustrative model of a heavy ion collision. The proton correlation function is sensitive to the presence of the critical point.