On the Origin of Gravitational Lorentz Covariance

TL;DR

This paper argues that general relativity uniquely describes the transverse, traceless graviton degrees of freedom with spatial covariance, suggesting Lorentz covariance may be an emergent symmetry rather than fundamental.

Contribution

It demonstrates that Lorentz covariance in general relativity may arise as an accidental symmetry, based on the uniqueness of the spatially covariant effective field theory for gravitons.

Findings

General relativity is the unique spatially covariant effective field theory for gravitons.

Lorentz covariance may be an emergent rather than fundamental symmetry.

The analysis does not assume Lorentz covariance a priori.

Abstract

We provide evidence that general relativity is the unique spatially covariant effective field theory of the transverse, traceless graviton degrees of freedom. The Lorentz covariance of general relativity, having not been assumed in our analysis, is thus plausibly interpreted as an accidental or emergent symmetry of the gravitational sector.