Non-singular black holes from gravity-matter-brane lagrangians

TL;DR

This paper constructs self-consistent non-singular black hole and wormhole solutions in Einstein-Maxwell systems coupled with lightlike branes, revealing how brane dynamics generate horizons, cosmological constants, and connect black hole regions.

Contribution

It introduces a novel approach using lightlike branes with variable tension to generate non-singular black holes and wormholes within Einstein-Maxwell theories.

Findings

Non-singular black hole solutions with de Sitter interior and Reissner-Nordström exterior.

Wormhole solutions connecting two non-singular black holes along their horizons.

Explicit determination of black hole parameters via brane tension.

Abstract

We consider self-consistent coupling of bulk Einstein-Maxwell-Kalb-Ramond system to codimension-one charged lightlike p-brane with dynamical (variable) tension (LL-brane). The latter is described by a manifestly reparametrization-invariant world-volume action significantly different from the ordinary Nambu-Goto one. We show that the LL-brane is the appropriate gravitational and charge source in the Einstein-Maxwell-Kalb-Ramond equations of motion needed to generate a self-consistent solution describing non-singular black hole. The latter consists of de Sitter interior region and exterior Reissner-Nordstroem region glued together along their common horizon (it is the inner horizon from the Reissner-Nordstroem side). The matching horizon is automatically occupied by the LL-brane as a result of its world-volume lagrangian dynamics, which dynamically generates the cosmological constant in the interior region and uniquely determines the mass and charge parameters of the exterior region. Using similar techniques we construct a self-consistent wormhole solution of Einstein-Maxwell system coupled to electrically neutral LL-brane, which describes two identical copies of a non-singular black hole region being the exterior Reissner-Nordstroem region above the inner horizon, glued together along their common horizon (the inner Reissner-Nordstroem one) occupied by the LL-brane. The corresponding mass and charge parameters of the two black hole "universes" are explicitly determined by the dynamical LL-brane tension. This also provides an explicit example of Misner-Wheeler "charge without charge" phenomenon. Finally, this wormhole solution connecting two non-singular black holes can be transformed into a special case of Kantowski-Sachs bouncing cosmology solution.