Testing Gravity Theories In The Radiative Regime Using Pulsar Timing Arrays

TL;DR

This paper reviews methods for testing gravity theories in the radiation regime by observing gravitational waves with pulsar timing arrays, focusing on differences in polarization and propagation speed predicted by alternative theories.

Contribution

It provides a comprehensive overview of recent proposals to distinguish general relativity from alternative gravity theories through pulsar timing observations.

Findings

Pulsar timing arrays can detect additional GW polarizations predicted by alternative theories.

Observations can test deviations in GW propagation speed from the speed of light.

The review highlights the potential of pulsar timing to constrain gravity theories.

Abstract

General relativity has predicted the existence of gravitational waves (GW), which are waves of the distortions of space-time with two degrees of polarization and the propagation speed of light. Alternative theories predict more polarizations, up to a maximum of six, and possible deviation of propagation speed from the light speed. The present paper reviews recent proposals to test the gravity theories in the radiation regime by observing GWs using pulsar timing arrays.