Nonsingular black holes, wormholes, and de Sitter cores from anisotropic fluids

TL;DR

This paper explores how Born-Infeld gravity coupled with anisotropic fluids can produce a variety of regular, nonsingular black holes, wormholes, and de Sitter cores, expanding the landscape of possible compact object solutions.

Contribution

It introduces new solution branches in Born-Infeld gravity with anisotropic fluids, demonstrating the existence of nonsingular black holes, wormholes, and de Sitter cores under specific conditions.

Findings

Multiple solution branches depending on parameter signs.

Existence of nonsingular black holes and wormholes.

Regular solutions with complete geodesics and finite curvature scalars.

Abstract

We study Born-Infeld gravity coupled to an anisotropic fluid in a static, spherically symmetric background. The free function characterizing the fluid is selected on the following grounds: i) recovery of the Reissner-Nordstr\"om solution of GR at large distances, ii) fulfillment of classical energy conditions and iii) inclusion of models of nonlinear electrodynamics as particular examples. Four branches of solutions are obtained, depending on the signs of two parameters on the gravity and matter sectors. On each branch, we discuss in detail the modifications on the innermost region of the corresponding solutions, which provides a plethora of configurations, including nonsingular black holes and naked objects, wormholes and de Sitter cores. The regular character of these configurations is discussed according to the completeness of geodesics and the behaviour of curvature scalars.