Tests of strong-field gravity and gravitational radiation damping in binary-pulsar systems

This talk reviews the constraints imposed by binary-pulsar data on gravity theories, and notably on "scalar-tensor" theories which are the most natural alternatives to general relativity. Because neutron stars have a strong gravitational binding energy, binary-pulsar tests are qualitatively different from solar-system experiments: They have the capability of probing models which are indistinguishable from general relativity in weak gravitational field conditions. Besides the two most precise binary-pulsar experiments, in the systems B1913+16 and B1534+12, we also present the results of the various "null" tests of general relativity provided by several neutron star-white dwarf binaries, notably those of gravitational radiation damping. [The main interest of this very short paper is its figure, which also takes into account the "strong equivalence principle" tests.]