Black Hole Evolution

TL;DR

This paper explores black hole formation, evaporation, and the information paradox within 1+1-dimensional models, discussing semiclassical solutions, boundary conditions, and a unitarity-based approach possibly linked to string theory.

Contribution

It provides exact semiclassical solutions and examines alternative unitary evolution models, addressing key issues in black hole physics and the information paradox.

Findings

Exact semiclassical solutions for black hole models

Discussion of boundary conditions and vacuum stability

Proposal of a unitarity-based evolution approach

Abstract

Black hole formation and evaporation is studied in the semiclassical approximation in simple 1+1-dimensional models, with emphasis on issues related to Hawking's information paradox. Exact semiclassical solutions are described and questions of boundary conditions and vacuum stability are discussed. The validity of the semiclassical approximation has been called into question in the context of the information puzzle. A different approach, where black hole evolution is assumed to be unitary, is described. It requires unusual causal properties and kinematic behavior of matter that may be realized in string theory. Based on lectures given at the 1994 Trieste Spring School