The search for Gravitational Waves: Status and perspectives

In this paper we give an overview of the present status and future perspectives of the search for gravitational waves. Gravitational Waves (GW) are predicted by the General Theory of the Relativity and, due to their very weak interaction with matter, can be an invaluable tool to look to the universe up to its very first moments. On the other hand, these same characteristics make their detection very difficult to achieve, and, at present, we have only indirect proof of their existence. In the last years the techniques adopted to directly detect GWs converged to laser interferometers. A world network of kilometer- scale laser interferometers is presently taking data but their sensitivity does not seem enough to give results in reasonable times. To this purpose all the presently working interferometers have plans to enhancement in the next few years and second- generation detectors, both ground and space based, are already in the design phase. PACS 04.80. Nn - Gravitational wave detectors and experiments. PACS 95.55. Ym - Gravitational radiation detectors; mass spectrometers; and other instrumentation and techniques.