Spinning Loop Black Holes

TL;DR

This paper constructs new Kerr-like loop black hole spacetimes using the Newman-Janis transformation, demonstrating they are singularity-free and analyzing their horizon structures and causality properties.

Contribution

It introduces a novel method to generate Kerr-like loop black hole solutions from Schwarzschild LBHs via Newman-Janis transformations, ensuring singularity resolution.

Findings

The resulting spacetimes are free of singularities.

Causality-violating regions are moved away from the core.

The horizon shapes are explicitly characterized.

Abstract

In this paper we construct four Kerr-like spacetimes starting from the loop black hole Schwarzschild solutions (LBH) and applying the Newman-Janis transformation. In previous papers the Schwarzschild LBH was obtained replacing the Ashtekar connection with holonomies on a particular graph in a minisuperspace approximation which describes the black hole interior. Starting from this solution, we use a Newman-Janis transformation and we specialize to two different and natural complexifications inspired from the complexifications of the Schwarzschild and Reissner-Nordstrom metrics. We show explicitly that the space-times obtained in this way are singularity free and thus there are no naked singularities. We show that the transformation move, if any, the causality violating regions of the Kerr metric far from r=0. We study the space-time structure with particular attention to the horizons shape. We conclude the paper with a discussion on a regular Reissner-Nordstrom black hole derived from the Schwarzschild LBH and then applying again the Newmann-Janis transformation.