Status and Prospect of Laser-Interferometric Gravitational Wave Astronomy

Abstract.

The existence of gravitational waves is the most prominent of Einstein’s predictions that has not yet been directly verified. The space project LISA shares its goal and principle of operation with the ground-based interferometers currently under construction: the detection and measurement of gravitational waves by laser interferometry. Ground and space detection differ in their frequency ranges, and thus in the detectable sources. Ground-based detection will allow detection only from a few Hz upwards, and up to a few kHz. On five sites worldwide, detectors of armlengths from 0.3 to 4 km are nearing completion. They will supply first scientific data in 2003. Only in space, detection of signals below, say, 1 Hz is possible. The project LISA consists of three spacecraft in heliocentric orbits, forming a triangle of 5 million km sides. Launch for LISA is scheduled for 2011, following a technology demonstrator LTP in 2006.