Spontaneous Lorentz Violation and the Long-Range Gravitational Preferred-Frame Effect

TL;DR

This paper investigates how spontaneous Lorentz violation in gravity, caused by a vector field's vacuum expectation value, leads to a preferred frame and modifies Newton's law, with implications for experimental constraints.

Contribution

It provides a calculation of the long-range preferred-frame effect in gravity due to spontaneous Lorentz violation, linking it to effective theory coefficients.

Findings

Quantifies the size of the preferred-frame effect in gravitational interactions.

Connects Lorentz-violating operators to observable modifications of Newton's law.

Offers a model-independent approach to constraining Lorentz violation in gravity.

Abstract

Lorentz-violating operators involving Standard Model fields are tightly constrained by experimental data. However, bounds are more model-independent for Lorentz violation appearing in purely gravitational couplings. The spontaneous breaking of Lorentz invariance by the vacuum expectation value of a vector field selects a universal rest frame. This affects the propagation of the graviton, leading to a modification of Newton's law of gravity. We compute the size of the long-range preferred-frame effect in terms of the coefficients of the two-derivative operators in the low-energy effective theory that involves only the graviton and the Goldstone bosons.