---
abstract: 'We analyze the response of the gravitational wave detector to a scalar massive plane gravitational wave. We give the compact form of the response and discuss its angular and frequency characteristics. The derivations is carried out in the conformal and the synchronous gauges and the equivalence of the two approaches is shown. In the case of the massive Brans–Dicke theory we solve the linearized vacuum field equations in the two gauges as well.'
author:
- 'Arkadiusz B[ł]{}aut'
title: Laser interferometer response to scalar massive gravitational waves
---

Introduction
============

Alternatives to the General Theory of Relativity (GR) were present already in the early times of its birth and subsequent periods of its development but a particular attention they have been drawing in the last two decades. The early attempts (see [@WillBook] and references therein) aimed at founding a theoretical framework for the ongoing weak–field, low–energy experiments in the Earth and the Solar System gravitational environments, strong–field astrophysical observations like those of pulsars and compact binary systems and then future gravitational wave detection experiments [@Eardley73] exploring dynamical, strong–field regime of gravity. The principal theoretical motivation for studying extensions of GR have been the unification of gravity with the rest 