Equivalence Principle and Gravitational Redshift

TL;DR

This paper explores deviations from general relativity that violate the Einstein equivalence principle, demonstrating the equivalence of different experimental tests and providing comprehensive limits on such violations.

Contribution

It shows the equivalence of matter wave and clock comparison experiments and sets limits on EEP-violating terms using multiple experimental methods.

Findings

Limits on EEP-violating terms at the 10^{-6} level

Equivalence of matter wave and clock comparison experiments

Comprehensive analysis of various experimental constraints

Abstract

We investigate leading order deviations from general relativity that violate the Einstein equivalence principle in the gravitational standard model extension. We show that redshift experiments based on matter waves and clock comparisons are equivalent to one another. Consideration of torsion balance tests, along with matter wave, microwave, optical, and M\"ossbauer clock tests, yields comprehensive limits on spin-independent Einstein equivalence principle-violating standard model extension terms at the $10^{-6}$ level.