Static Vacuum Solutions in Non-Riemannian Gravity

TL;DR

This paper derives exact static vacuum solutions in non-Riemannian gravity with torsion, revealing deviations from General Relativity's predictions and exploring black hole thermodynamics extensions.

Contribution

It introduces new static vacuum solutions in non-Riemannian gravity with torsion, analyzing their horizons and thermodynamics, extending classical black hole models.

Findings

Solutions exhibit event horizons similar to Schwarzschild and Reissner-Nordström black holes.

Torsion influences perihelion precession and light bending predictions.

Torsion modifies Hawking radiation and black hole thermodynamics.

Abstract

In the framework of non-riemannian geometry, we derive exact static vacuum solutions of the field equations obtained from the full equivalent version of the Einstein-Hilbert action when torsion degrees of freedom are taken into account. By imposing spherical symmetry and a suitable choice for the contorsion degrees of freedom, the static geometry provides deviations on the predictions of the observational tests predicted by General Relativity -- namely on the advance of planetary perihelia and the bending of light rays -- which we infer. The analytical extension is built in two particular domains of the parameter space. In the first domain we obtain a solution exhibiting an event horizon analogous to that of the Schwarzschild geometry. For the second domain, we show that the metric furnishes an exterior event horizon, and two interior horizons which enclose the singularity. For both branches we examine the effects of torsion corrections on the Hawking radiation. In this scenario the model extends Bekenstein's black hole geometrical thermodynamics, with an extra work term connected to a torsion parameter.