Melvin Universe in Born-Infeld gravity

TL;DR

This paper derives an analytic solution for a magnetic flux in a Born-Infeld gravity extension of GR, exploring implications for early Universe phenomena like wormholes and black hole remnants.

Contribution

It provides the first formal analytic solution for the Melvin Universe in a Born-Infeld gravity framework using the Palatini approach.

Findings

Recovers GR results in appropriate limits

Sets groundwork for embedding black hole remnants in magnetic fields

Suggests potential phenomenology in early Universe scenarios

Abstract

We consider a magnetic flux pointing in the $z$ direction of an axially symmetric space-time (Melvin Universe) in a Born-Infeld-type extension of General Relativity (GR) formulated in the Palatini approach. Large magnetic fields could have been produced in the early Universe, and given rise to interesting phenomenology regarding wormholes and black hole remnants. We find a formal analytic solution to this problem that recovers the GR result in the appropriate limits. Our results set the basis for further extensions that could allow the embedding of pairs of black hole remnants in geometries with intense magnetic fields.