General relativity and the spiral of compact binary stars
  The theory of general relativity, which is extremely well verified by classic tests in the solar system as well as by the radiation of the binary pulsar, is one of the fundamental tools of nowadays astrophysics. It permits the computation of the gravitational wave form emitted during the inspiral phase of binary systems of neutron stars and black holes. Based on the so-called post-Newtonian approximation (developped to high order), the prediction of general relativity is used as a "template" for searching and analysing the signals in the network of gravitational-wave detectors VIRGO/LIGO. 
Luc Blanchet