Large quantum gravity effects: backreaction on matter

TL;DR

This paper investigates how large quantum gravity effects influence matter and spacetime, exploring different quantum states to understand their observability and impact on coherence and metric fluctuations.

Contribution

It introduces an alternative family of coherent states in 2+1 gravity coupled to matter, analyzing their effects on metric fluctuations and matter coherence.

Findings

Large quantum gravity effects can be reduced in certain states.

The choice of quantum states affects the observability of metric fluctuations.

Loss of matter coherence correlates with large quantum gravity effects.

Abstract

We reexamine the large quantum gravity effects discovered by Ashtekar in the context of 2+1 dimensional gravity coupled to matter. We study an alternative one-parameter family of coherent states of the theory in which the large quantum gravity effects on the metric can be diminished, at the expense of losing coherence in the matter sector. Which set of states is the one that occurs in nature will determine if the large quantum gravity effects are actually observable as wild fluctuations of the metric or rapid loss of coherence of matter fields.