Emergent Models for Gravity: an Overview of Microscopic Models

TL;DR

This paper reviews various approaches to modeling gravity as an emergent phenomenon, focusing on condensed matter analogies and pregeometric models, emphasizing the idea of the graviton as a composite or collective mode.

Contribution

It provides a comprehensive overview of different microscopic models and methods used to describe gravity as emergent, highlighting the diversity of approaches and ideas.

Findings

Multiple models treat the graviton as a composite particle.

Condensed matter analogies offer insights into emergent gravity.

Pregeometric models explore fundamental structures underlying spacetime.

Abstract

We give a critical overview of various attempts to describe gravity as an emergent phenomenon, starting from examples of condensed matter physics, to arrive to more sophisticated pregeometric models. The common line of thought is to view the graviton as a composite particle/collective mode. However, we will describe many different ways in which this idea is realized in practice.