Séminaire Astro-PSA (II) : Probing gravity with radio pulsars

vendredi 25 oct. 2013, 10:30 → 12:00 Europe/Paris

Amphi Coupole (Observatoire)

Séminaires communs des Masters

"Astrophysique"

et

"Physique Subatomique et Astroparticules"

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Probing Gravity with radio pulsars

par Norbert Wex (Max-Planck-Institut für radioastronomie, Bonn)

Résumé

Before the 1970s, precision tests for gravity theories were constrained to the weak gravitational fields of the Solar system. Hence, only the weak-field slow-motion aspects of relativistic celestial mechanics could be investigated. Testing gravity beyond the first post-Newtonian contributions was for a long time out of reach. 

The discovery of the first binary pulsar by Russell Hulse and Joseph Taylor in the summer of 1974 initiated a completely new field for testing relativistic gravity. For the first time the back reaction of 
gravitational wave emission on the binary motion could be studied, which gave the first evidence for the existence of gravitational waves as predicted by Einstein's general relativity. Furthermore, the 
Hulse-Taylor pulsar provided the first test bed for the gravitational interaction of strongly self-gravitating bodies. 

To date there are a number of radio pulsars known, which can be utilized for precision test of gravity. Depending on their orbital properties and their companion, these pulsars provide tests for various different aspects of gravity. Besides tests of specific theories, like general relativity or scalar-tensor gravity, there are pulsars that allow for generic constraints on deviations of gravity from general relativity in the quasi-stationary strong-field regime and in the generation of gravitational waves. 

I my talk I give an introduction to gravity tests with radio pulsars, and highlight some of the most important results. In addition, I give a brief outlook into the future of this exciting field of experimental gravity.