1207.5388 (Ram Brustein et al.)

Universal stress-tensor correlation functions of strongly coupled
conformal fluids    [PDF]

Ram Brustein, A. J. M. Medved

The gauge-gravity duality relates on-shell graviton multi-point functions in an anti-de Sitter black brane background to stress-tensor correlation functions of strongly coupled fluids. We show that, for conformal fluids whose gravitational dual is Einstein gravity, such correlation functions are universal in a particular kinematic region and depend only on the Mandelstam variable s. Thus, we extend the universality of the two-point function or, equivalently, the universality of the shear viscosity to entropy ratio to multi-point correlation functions. We also consider the leading corrections to Einstein gravity in string theory. The effect of these corrections is similarly universal, inducing a specific difference in the angular dependence of the stress-tensor correlation functions in the same kinematic region. We discuss schematically how multi-particle correlations in heavy-ion collisions can be used to test these findings and, thereby, probe the existence of a gravitational dual to the quark-gluon plasma and its universality class. We also propose a new way to measure the shear viscosity to entropy ratio using multi-point correlation functions.

View original: http://arxiv.org/abs/1207.5388