Einstein-aether gravity: a status report

TL;DR

This paper reviews Einstein-aether gravity, discussing its theoretical framework, phenomenological implications, and observational constraints, while highlighting open questions in both fundamental theory and phenomenology.

Contribution

It provides a comprehensive status report on Einstein-aether gravity, summarizing recent developments and identifying key open issues.

Findings

Constraints on coupling parameters from observations

Phenomenological implications of the dynamical vector field

Open questions in fundamental aspects of the theory

Abstract

This paper reviews the theory, phenomenology, and observational constraints on the coupling parameters of Einstein-aether gravity, i.e. General Relativity coupled to a dynamical unit timelike vector field. A discussion of open questions concerning both phenomenology and fundamental issues is included.