Gravitational Waves: An Introduction

In this article, I present an elementary introduction to the theory of gravitational waves. This article is meant for students who have had an exposure to general relativity, but, results from general relativity used in the main discussion has been derived and discussed in the appendices. The weak gravitational field approximation is first considered and the linearized Einstein’s equations are obtained. We discuss the plane wave solutions to these equations and consider the transverse-traceless (TT) gauge. We then discuss the motion of test particles in the presence of a gravitational wave and their polarization. The method of Green’s functions is applied to obtain the solutions to the linearized field equations in presence of a nonrelativistic, isolated source. Mehta Research Institute, Chhatnag Road, Jhusi. Allahabad. 211 019 INDIA E-mail: [email protected]