Towards Gravity from the Quantum

TL;DR

This paper explores the emergence of gravity from a fundamental quantum information framework, proposing that general relativity is an effective theory arising from a non-geometric quantum substrate.

Contribution

It introduces a novel approach to derive gravity as an effective phenomenon from a background-independent quantum information theoretic model.

Findings

Identification of effective coherent degrees of freedom using noiseless subsystems

Implications of effective locality and time in quantum gravity models

Proposes gravity as an emergent, effective theory from quantum information processing

Abstract

We review quantum causal histories starting with their interpretations as a quantum field theory on a causal set and a quantum geometry. We discuss the difficulties that background independent theories based on quantum geometry encounter in deriving general relativity as the low energy limit. We then suggest that general relativity should be viewed as a strictly effective theory coming from a fundamental theory with no geometric degrees of freedom. The basic idea is that an effective theory is characterized by effective coherent degrees of freedom and their interactions. Having formulated the pre-geometric background independent theory as a quantum information theoretic processor, we are able to use the method of noiseless subsystems to extract such coherent (protected) excitations. We follow the consequences, in particular, the implications of effective locality and time.