Relativistic Viscous Fluid Description of Microscopic Black Hole Wind

Microscopic black holes explode with their temperature varying inversely as their mass. Such explosions would lead to the highest temperatures in the present Universe, all the way to the Planck energy. Whether or not a quasistationary shell of interacting matter undergoing radial hydrodynamic expansion surrounds such black holes is controversial. In this paper relativistic viscous fluid equations are applied to the problem assuming sufficient particle interaction. It is shown that a self-consistent picture emerges of a fluid just marginally kept in local thermal equilibrium; viscosity is a crucial element of the dynamics.