Gravitational waves in geometric scalar gravity

TL;DR

This paper explores gravitational waves within the geometric scalar gravity theory, highlighting their unique polarization modes and energy characteristics, and compares these features to those in general relativity.

Contribution

It introduces the analysis of gravitational waves in GSG, emphasizing their longitudinal polarization and energy emission, which are distinct from general relativity.

Findings

GSG predicts longitudinal polarization modes in gravitational waves.

The energy carried by GSG gravitational waves is characterized.

Binary system orbital periods are affected by GSG gravitational wave emission.

Abstract

We investigate the gravitational waves phenomena in the geometric scalar theory of gravity (GSG) that belongs to a class of theories such that gravity is described by a single scalar field. The associated physical metric describing the spacetime is constructed from a disformal transformation of Minkowski geometry. In this theory, a weak field approximation gives rise to a description similar to that one obtained in general relativity, although the gravitational waves in GSG have a characteristic longitudinal polarization mode, besides others modes that are observer dependent. We also analyze the energy carried by the gravitational waves as well as how their emission affects the orbital period of a binary system.