Observing quantum gravity in asymptotically AdS space

TL;DR

This paper explores how an observer can detect quantum gravity effects in asymptotically AdS space using specialized detectors, revealing insights into topologically inequivalent geometries and the nature of CFT states related to black holes.

Contribution

It demonstrates the possibility of probing quantum gravity effects via designed detectors and discusses the implications for CFT states describing AdS black holes.

Findings

Quantum gravity effects can be detected with appropriate detectors.

CFT states for black holes may be restricted to boundary patches.

Bulk CFT operators can mimic semi-classical quantum fields in large N limit.

Abstract

A question is studied whether an observer can discover quantum gravity being in the semi-classical regime. It is shown that it is indeed possible to probe a certain quantum gravity effect by employing an appropriately designed detector. The effect is related to the possibility of having topologically inequivalent geometries at once in the path integral approach. A CFT state which is expected to describe the eternal AdS black hole in the large N limit is discussed. It is argued under certain assumptions that the black hole boundary should be merely a patch of the entire AdS boundary. This leads then to a conclusion that that CFT state is the ordinary CFT vacuum restricted to that patch. If existent, the bulk CFT operators can behave as the ordinary semi- classical quantum field theory in the large N limit in the weak sense.