A new pulsar timing model for scalar-tensor gravity with applications to PSR J2222-0137 and pulsar-black hole binaries

Vol. 686
11. Celestial mechanics and astrometry

A new pulsar timing model for scalar-tensor gravity with applications to PSR J2222-0137 and pulsar-black hole binaries

General relativity has been tested in great detail thanks to relativistic binary pulsars. The double binary pulsar PSR J0737-3039 allowed us to reach a 99.99% accuracy. Despite this, tests of alternative theories of gravity continue (and must continue for the good of science). In this paper, Batrakov and collaborators put forward a new formalism to enable the testing of scalar-tensor theories of gravity (STG). In this class of theories, an additional scalar field is coupled to matter such that the law of gravitation is dependent on velocity and/or location. The authors then apply this new formalism (called DDSTG) to the binary pulsar PSR J2222-0137, slightly improving the existing limits of STG theories. They also discuss the limits that can be reached with an as yet undiscovered neutron star-black hole binary system.