Was Einstein right? - Unique tests of GR with the Double Pulsar

Michael Kramer: University of Manchester, Jodrell Bank Observatory

The recent discovery of the double pulsar has lived up to its promise to provide the most exciting laboratory for general relativity currently available. The system consists of two active radio pulsars which orbit each other in only 144 minutes. As a result, a large number of relativistic effects can be observed which include a huge precision of the orbit, a gravitational redshift of the pulsar clocks, a Shapiro delay, a decay of the orbit due to gravitational wave emission and the effects of frame dragging and geodetic precession. With the addition of the unique, theory-independent constraint provided by the mass ratio of the stars, available through the measurement of both orbits about the common centre of mass, the system provides the best test of general relativity in the strong field limit. The talk will summarize the most recent results by demonstrating the wide range of relativistic effects that are observable, and will look ahead into the future, where the determination of a neutron star's moment of inertia may be possible for the first time via relativistic spin-orbit coupling.