Constraining Lorentz violation with cosmology

TL;DR

This paper investigates how Einstein-Aether theory, which introduces Lorentz violation, affects cosmology and uses observational data to constrain its parameters, showing it can fit data with specific adjustments.

Contribution

It provides a comprehensive analysis of Einstein-Aether theory's cosmological implications and derives observational constraints on its parameters.

Findings

Einstein-Aether theory can fit cosmological data within certain parameter ranges.

A specific rescaling of cosmological densities is necessary for compatibility.

The theory remains consistent with experimental constraints across a wide parameter space.

Abstract

The Einstein-Aether theory provides a simple, dynamical mechanism for breaking Lorentz invariance. It does so within a generally covariant context and may emerge from quantum effects in more fundamental theories. The theory leads to a preferred frame and can have distinct experimental signatures. In this letter, we perform a comprehensive study of the cosmological effects of the Einstein-Aether theory and use observational data to constrain it. Allied to previously determined consistency and experimental constraints, we find that an Einstein-Aether universe can fit experimental data over a wide range of its parameter space, but requires a specific rescaling of the other cosmological densities.