Geometry Of Charged Black Holes Research Articles

Numerical evolution of the interior geometry of charged black holes

Previously, we developed a late time approximation scheme to study the interior geometry of black holes. In the present paper we test this scheme with numerical relativity simulations. In particular, we present numerical relativity simulations of the interior geometry of charged spherically symmetric two-sided black holes with a spacelike singularity at $r = 0$. Our numerics are in excellent agreement with the late time approximation. We also demonstrate that the geometry near $r = 0$ is a scalarized Kasner geometry and compute the associated Kasner exponents.

Global geometry of two-dimensional charged black holes

The semiclassical geometry of charged black holes is studied in the context of a two-dimensional dilaton gravity model where effects due to pair-creation of charged particles can be included in a systematic way. The classical mass-inflation instability of the Cauchy horizon is amplified and we find that gravitational collapse of charged matter results in a spacelike singularity that precludes any extension of the spacetime geometry. At the classical level, a static solution describing an eternal black hole has timelike singularities and multiple asymptotic regions. The corresponding semiclassical solution, on the other hand, has a spacelike singularity and a Penrose diagram like that of an electrically neutral black hole. Extremal black holes are destabilized by pair-creation of charged particles. There is a maximally charged solution for a given black hole mass but the corresponding geometry is not extremal. Our numerical data exhibits critical behavior at the threshold for black hole formation.

Semiclassical geometry of charged black holes

At the classical level, two-dimensional dilaton gravity coupled to an abelian gauge field has charged black hole solutions, which have much in common with four-dimensional Reissner-Nordstr\"om black holes, including multiple asymptotic regions, timelike curvature singularities, and Cauchy horizons. The black hole spacetime is, however, significantly modified by quantum effects, which can be systematically studied in this two-dimensional context. In particular, the back-reaction on the geometry due to pair-creation of charged fermions destabilizes the inner horizon and replaces it with a spacelike curvature singularity. The semiclassical geometry has the same global topology as an electrically neutral black hole.