Kinematic and energy properties of dynamical regular black holes

TL;DR

This paper investigates the kinematic and energy properties of dynamical regular black holes, exploring their horizons, energy conditions, and implications for black hole thermodynamics and information loss, based on a generalized model.

Contribution

It introduces a dynamical generalization of regular black holes and analyzes their properties, including horizon crossing and energy conditions, extending previous static models.

Findings

Horizons can be crossed on ingoing geodesics.

Null energy condition is examined near horizons and interior.

Implications for information loss and thermodynamics are discussed.

Abstract

Nonsingular black holes have received much attention in recent years as they provide an opportunity to avoid the singularities inherent to the mathematical black holes predicted by general relativity. Based on the assumption that semiclassical physics remains valid in the vicinity of their horizons, we derive kinematic properties of dynamically evolving spherically symmetric regular black holes. We review the Hawking--Ellis classification of their associated energy-momentum tensors and examine the status of the null energy condition in the vicinity of their horizons as well as their interior. In addition, we analyze the trajectory of a moving observer, find that the horizons can be crossed on an ingoing geodesic, and thus entering and exiting the supposedly trapped spacetime region is possible. We outline the ramifications of this result for the information loss problem and black hole thermodynamics. Throughout the article, we illustrate relevant features based on the dynamical generalization of the regular black hole model proposed in J. High Energy Phys. 09, 118 (2022) and elucidate connections to the only self-consistent dynamical physical black hole solutions in spherical symmetry.