Applied Holography of the AdS$_5$-Kerr Spacetime

Asymptotically Anti-de Sitter Kerr black holes (we focus here on the five-dimensional case) are associated holographically with matter at conformal infinity which has a non-zero angular momentum density. It is natural to attempt to associate this angular momentum with the recently discovered vorticity of the plasmas produced in peripheral heavy-ion collisions. We assume that an AdS$_5$-Kerr black hole with angular momentum to mass ratio $\mathcal{A}$ is dual to boundary matter with an angular momentum density to energy density ratio also equal to $\mathcal{A}$. With this assumption, we find that, for collisions corresponding to a given value of $\mathcal{A}$, there is a maximal possible angular velocity (well below the maximal value permitted by causality) for such matter at infinity, and that this value is in approximate agreement with the experimentally reported value of the average plasma vorticity produced in typical peripheral collisions of heavy ions.