A Nonsingular Kerr-Sen Black Hole

TL;DR

This paper introduces a new four-dimensional rotating regular charged black hole solution in heterotic string theory, analyzing its horizon, ergosphere, and regularity using scalar invariants, and discusses its physical properties and energy conditions.

Contribution

It provides a novel nonsingular rotating charged black hole solution in heterotic string theory, with analysis of its horizon, ergosphere, and regularity properties.

Findings

The solution describes a regular black hole with charge and rotation.

Charge does not compromise the black hole's regularity.

A minimal violation of weak energy conditions is proposed.

Abstract

We present a novel solution describing four dimensional rotating regular charged black hole in the low energy heterotic string theory. This present solution is characterized by its mass, charged, as well as angular momentum. Some aspect including event horizon, ergosphere, and the angular velocity are discussed. It is shown that later, our expression for event horizon and ergosphere cannot be obtained analytically. On the other hand, to ensure whether our solution describe a nonsingular rotating charged black hole, we use two type of scalar invariant; contracted Ricci tensor and Kretschmann scalar. From our result, the inclusion of charge does not alter the regularity of a black hole. We also proposed a natural prescription to have rotating charged black hole solution with a minimal violation of weak energy conditions.