Low temperature and gravitational wave detectors

The success of a precision experiment is often associated to the use of low temperature techniques. In particular, when the thermal noise is a barrier for improv- ing the experiment sensitivity, the cryogenics is crucial for beating this limitation. This strategy was applied in the case of the resonant gravitational wave detectors (GW) and now it is proposed for the future generation of the GW interferometers. In the following we summarize the history of GW detector and we recall some of the basic principles of the cryogenic techniques. Then, we focus on the issues of cooling the mirrors of a GW interferometer