On the longitudinal response function of interferometers for massive gravitational waves from a bimetric theory of gravity

TL;DR

This paper calculates the longitudinal response function of interferometers to massive gravitational waves predicted by a bimetric gravity theory, demonstrating gauge invariance and applying results to Virgo and LIGO.

Contribution

It provides the first detailed computation of the interferometer response to longitudinal massive gravitational waves in two gauges, including full frequency dependence.

Findings

Response function is gauge invariant.

Longitudinal component affects interferometer signals.

Results applied to Virgo and LIGO detectors.

Abstract

Recently, some papers in the literature have shown that, from a bimetric theory of gravity, it is possible to produce massive gravitational waves which generate a longitudinal component in a particular polarization of the wave. After a review of previous works, in this paper the longitudinal response function of interferometers for this particular polarization of the wave is computed in two different gauges, showing the gauge invariance, and in its full frequency dependence, with specific application to the Virgo and LIGO interferometers.