Black Hole Evaporation without Information Loss

TL;DR

This paper proposes a quantum black hole model that preserves coherence, leading to a unitary S-matrix and avoiding information loss, with implications for black hole topology and thermality of emitted particles.

Contribution

It introduces a novel black hole quantization approach that maintains quantum coherence and demonstrates unitarity in the S-matrix within a background field framework.

Findings

S-matrix for soft particles remains unitary

Particle spectrum is approximately thermal

Topological constraints influence functional integrals

Abstract

An approach to black hole quantization is proposed wherein it is assumed that quantum coherence is preserved. A consequence of this is that the Penrose diagram describing gravitational collapse will show the same topological structure as flat Minkowski space. After giving our motivations for such a quantization procedure we formulate the background field approximation, in which particles are divided into "hard" particles and "soft" particles. The background space-time metric depends both on the in-states and on the out-states. We present some model calculations and extensive discussions. In particular, we show, in the context of a toy model, that the $S$-matrix describing soft particles in the hard particle background of a collapsing star is unitary, nevertheless, the spectrum of particles is shown to be approximately thermal. We also conclude that there is an important topological constraint on functional integrals.