Göttingen 2012 – scientific programme

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GR: Fachverband Gravitation und Relativitätstheorie

GR 19: Hauptvorträge Relativistische Astrophysik

GR 19.2: Invited Talk

Friday, March 2, 2012, 11:45–12:30, ZHG 002

Probing the nature of gravity with radio pulsars — •Norbert Wex — Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany

Nearly four decades have passed since the discovery of the first radio pulsar in a binary system by Joseph Taylor and Russell Hulse. The most well-known use of this precise "cosmic clock" has been its role in tests of gravity theories, in particular in the (indirect) verification of the existence of gravitational waves.

Since then, additional binary pulsars have been discovered, allowing us to test different aspects of gravity. A particularly interesting system in this respect is the so-called "Double Pulsar", a unique system where two active radio pulsars orbit each other in less than 2.5 hours.

Currently there are efforts to find the first pulsar orbiting a black hole. This would complement the pulsar gravity tests in a unique way. The ultimate laboratory would be a pulsar in a tight orbit around the supermassive black hole in the centre of our Galaxy.

In addition to gravity tests with the binary motion of pulsars, there is presently a world wide effort for a direct detection of nano-Hz gravitational waves from supermassive black hole binaries, using an array of pulsars with very high rotational stability.

After a short introduction to pulsars and pulsar timing, I will summarise some of the more recent gravity tests with binary pulsars, outline the potential of a pulsar-black hole system which is yet to be discovered, and highlight some aspects of using pulsars as a gravitational wave detector.