Two-dimensional dilaton gravity in a unitary gauge

TL;DR

This paper develops a unitary quantum formulation of 2D dilaton gravity, showing that black hole evaporation does not follow Hawking's scenario, with implications for black hole information loss.

Contribution

It introduces a reduced phase space approach in a specific gauge, promoting the Hamiltonian to a Hermitian operator ensuring unitarity in black hole evolution.

Findings

Hamiltonian promoted to Hermitian operator ensures unitarity

Black hole evaporation does not follow Hawking's scenario

Implications for black hole information paradox

Abstract

Reduced phase space formulation of CGHS model of 2d dilaton gravity is studied in en extrinsic time gauge. The corresponding Hamiltonian can be promoted into a Hermitian operator acting in the physical Hilbert space, implying a unitary evolution for the system. Consequences for the black hole physics are discussed. In particular, this manifestly unitary theory rules out the Hawking scenario for the endpoint of the black hole evaporation process.