Recycled binary pulsars—a most precise laboratory of fundamental physics

Abstract

We discuss here the problems connected with radio pulsars in close binary systems, which have an anomalously small magnetic field and rotate very rapidly. The first discovered Hulse–Taylor binary pulsar permitted us to make the indirect discovery of gravitational waves. Later single recycled pulsars (RPs) that had been in binaries before the disruption of the pairs were found. The mechanism of the pair disruption and the formation of a single RP is considered on the basis of the mechanism of enhanced evaporation. General relativity effects in the pairs connecting two neutron stars (NSs) and, in particular, in a double-pulsar system are considered. Timing observations of NS+NS binary pulsars provide a unique means of checking general relativity and the variability of the gravitational constant.