Properties of nonextremal enhançons

We study the supergravity solutions describing nonextremal enhançons. There are two branches of solutions: a “shell branch” connected to the extremal solution, and a “horizon branch” which connects to the Schwarzschild black hole at large mass. We show that the shell branch solutions violate the weak energy condition, and are hence unphysical. We investigate linearized perturbations of the horizon branch and the extremal solution numerically, completing an investigation initiated in a previous paper. We show that these solutions are stable against the perturbations we consider. This provides further evidence that these latter supergravity solutions are capturing some of the true physics of the enhançon.