Position and frequency shifts induced by massive modes of the gravitational wave background in alternative gravity

TL;DR

This paper explores how massive modes of gravitational waves in alternative gravity theories cause unique position and frequency shifts in light, offering potential observational signatures to distinguish these theories from general relativity.

Contribution

It analyzes the impact of massive scalar, vector, and tensor gravitational wave modes on light propagation, highlighting their potential as signatures of alternative gravity theories.

Findings

Massive gravitational wave modes induce distinct position shifts.

Frequency shifts caused by these modes differ from general relativity predictions.

Potential observational signatures for testing alternative gravity theories.

Abstract

Alternative theories of gravity predict the presence of massive scalar, vector, and tensor gravitational wave modes in addition to the standard massless spin~2 graviton of general relativity. The deflection and frequency shift effects on light from distant sources propagating through a stochastic background of gravitational waves, containing such modes, differ from their counterparts in general relativity. Such effects are considered as a possible signature for alternative gravity in attempts to detect deviations from Einstein's gravity by astrophysical means.