On the condensed matter scheme for emergent gravity and interferometry

TL;DR

This paper explores the idea that gravity and other gauge fields might be emergent phenomena from microscopic physics, similar to condensed matter systems, and discusses how interferometry could test this emergent gravity hypothesis.

Contribution

It proposes using interferometry to investigate the condensed matter scheme of emergent gravity, linking historical ether concepts with modern quantum gravity ideas.

Findings

Interferometry may provide insights into emergent gravity phenomena.

Gravity could be an effective low-energy collective excitation.

The condensed matter analogy offers a new perspective on quantum vacuum properties.

Abstract

An increasingly popular approach to quantum gravity rests on the idea that gravity (and maybe electromagnetism and the other gauge fields) might be an 'emergent phenomenon', in the sense of representing a collective behaviour resulting from a very different microscopic physics. A prominent example of this approach is the condensed matter scheme for quantum gravity, which considers the possibility that gravity emerges as an effective low-energy phenomenon from the quantum vacuum in a way similar to the emergence of collective excitations in condensed matter systems. This condensed matter view of the quantum vacuum clearly hints that, while the term 'ether' has been discredited for about a century, quantum gravity holds many (if not all) of the characteristics that have led people in the past to label various hypothetical substances with the term 'ether'. Since the last burst of enthusiasm for an ether, at the end of the 19th century, was brought to the grave in part by the performance of a series of important experiments in interferometry, the suggestion then naturally arises that maybe interferometry could also play a role in the current discussion on quantum gravity. We will highlight some aspects of this suggestion in the context of the condensed matter scheme for emergent gravity.