Gravitational wave astronomy— astronomy of the 21st century

Abstract

An enigmatic prediction of Einstein's general theory of rel ativity are gravitational waves. With the observed decay in the orbit of the Hulse-Taylor binary pulsar agreeing within a fraction of a percent with the theor etically computed decay from Einstein's theory the existence of gravitational wave s was firmly established. Currently there is a worldwide effort to detect gravitational waves with inteferomet- ric gravitational wave observatories or detectors and seve ral such detectors have been built or being built. The initial detectors have reached the ir design sensitivities and now the effort is on to construct advanced detectors which are expected to detect grav- itational waves from astrophysical sources. The era of Grav itational Wave Astronomy has arrived. This article describes the worldwide effort which includes the effort on the Indian front - the IndIGO project -, the principle underlyin g interferometric detectors both on ground and in space, the principal noise sources that plague such detectors, the astrophysical sources of gravitational waves that one e xpects to detect by these de- tectors and some glimpse of the data analysis methods involved in extracting the very weak gravitational wave signals from detector noise.