Universality of the diffusion wake in the gauge-string duality

As a particle moves through a fluid, it may generate a laminar wake behind it. In the gauge-string duality, we show that such a diffusion wake is created by a heavy quark moving through a thermal plasma and that it has a universal strength when compared to the total drag force exerted on the quark by the plasma. The universality extends over all asymptotically anti-de Sitter supergravity constructions with arbitrary scalar matter. We discuss how these results relate to the linearized hydrodynamic approximation and how they bear on our understanding of di-hadron correlators in heavy ion collisions. September 2007 ∗e-mail: [email protected] †e-mail: [email protected] ar X iv :0 70 9. 10 89 v1 [ he pth ] 7 S ep 2 00 7