Reflection from black holes

TL;DR

This paper demonstrates that quantum effects enable particles to reflect off black hole event horizons, suggesting black holes can act as mirrors rather than perfect absorbers, which impacts our understanding of their physical nature.

Contribution

It introduces the concept of quantum reflection at black hole horizons, challenging the traditional view of black holes as perfect absorbers and proposing observable implications.

Findings

Quantum corrections enable particle reflection from black hole horizons.

Black holes can behave as mirrors for low energy particles.

Potential observational signatures of reflection are discussed.

Abstract

Black holes are presumed to have an ideal ability to absorb and keep matter. Whatever comes close to the event horizon, a boundary separating the inside region of a black hole from the outside world, inevitably goes in and remains inside forever. This work shows, however, that quantum corrections make possible a surprising process, reflection: a particle can bounce back from the event horizon. For low energy particles this process is efficient, black holes behave not as holes, but as mirrors, which changes our perception of their physical nature. Possible ways for observations of the reflection and its relation to the Hawking radiation process are outlined.