Interior of Black Holes and Information Recovery

TL;DR

This paper investigates the internal structure and evolution of evaporating black holes, proposing that collapsing matter evaporates without horizon formation and exploring implications for information recovery and internal metrics.

Contribution

It introduces a model where collapsing matter evaporates before horizon formation, and derives the interior metric considering quantum effects and black hole charge and rotation.

Findings

Matter evaporates without forming a horizon.

Hawking-like radiation occurs without a true horizon.

Interior structure influenced by Weyl anomaly and quantum effects.

Abstract

We analyze time evolution of a spherically symmetric collapsing matter from a point of view that black holes evaporate by nature. We first consider a spherical thin shell that falls in the metric of an evaporating Schwarzschild black hole of which the radius $a(t)$ decreases in time. The important point is that the shell can never reach $a(t)$ but it approaches $a(t)-a(t)\frac{d a(t)}{d t}$. This situation holds at any radius because the motion of a shell in a spherically symmetric system is not affected by the outside. In this way, we find that the collapsing matter evaporates without forming a horizon. Nevertheless, a Hawking-like radiation is created in the metric, and the object looks the same as a conventional black hole from the outside. We then discuss how the information of the matter is recovered. We also consider a black hole that is adiabatically grown in the heat bath and obtain the interior metric. We show that it is the self-consistent solution of $G_{\mu\nu}=8\pi G \langle T_{\mu\nu} \rangle$ and that the four-dimensional Weyl anomaly induces the radiation and a strong angular pressure. Finally, we analyze the internal structures of the charged and the slowly rotating black holes.