On a New Kind of Echo from Quantum Black Holes

by Sreenath K. Manikandan (Nordita)

Wednesday 23 Feb 2022, 13:30 → 14:30 Europe/Stockholm

Albano 3: 6228 - Mega (22 seats) (Albano Building 3)

Hybrid talk: Mega (6228, Hus 3, Albano) + https://stockholmuniversity.zoom.us/j/530682073

In this talk, we will discuss a recent proposal that a quantum black hole can produce a new kind of  late-time gravitational echoes, facilitated by a near-horizon process analogous to Andreev reflection in condensed matter systems. In comparison to the traditional echo scenarios where the near-horizon region is treated as an ordinary reflector, we argue that, consequent to near-horizon gravitational scattering, this region is better described by an Andreev reflector. Such interactions lead to a novel contribution to gravitational echoes with a characteristic phase difference, an effect which is analogous to how Andreev reflections lead to propagating particle-like and hole-like components with a relative phase in certain condensed matter scenarios. Moreover, this novel contribution to the echo signal encodes information about the `near-horizon quantum state', hence offering a possible new window to probe the quantum nature of black holes. 

 

Reference: https://arxiv.org/abs/2112.08773