Blackhole evaporation model without information loss

TL;DR

This paper presents a model of blackhole evaporation that preserves information by considering the blackhole as a superposition of mass states entangled with radiation, ensuring unitary evolution and no information loss.

Contribution

It introduces a simple superposition-based model of blackhole evaporation that maintains unitarity and resolves the information loss paradox.

Findings

Blackhole evolution is unitary in the model.

Entanglement entropy initially increases then decreases to zero.

Blackhole mass distribution remains sharply peaked.

Abstract

A simple model of a blackhole evaporation without information loss is given. In this model, the blackhole is \textit{not} in a specific mass eigenstate as it evaporates but rather, is in a superposition of various mass eigenstates and is entangled with the radiation. For astrophysical blackhole, the mass distribution is sharply peak about its average value with a vanishingly small standard deviation, which is consistent with our intuition of a classical object. It is then shown that as the blackhole evaporates, the evolution of the closed blackhole-radiation system is unitary. This is done by showing that the full density matrix satisfies Tr$\rho^2=1$ at all times. Finally, it is shown that the entanglement entropy, after an initial increase, decreases and approaches zero. These show that this model of blackhole evaporation has no infromation loss.