2008/04/07 by N. D. R. Bhat, N. D. Ramesh Bhat, Matthew Bailes +3 · 7 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Cosmology and Gravitation Theories #Pulsars and Gravitational Waves Research #astro-ph #gr-qc
paper · pdf · doi:10.1103/physrevd.77.124017
published as Phys.Rev.D77:124017,2008 · 4 pages, 2 figures, To Appear in Physical Review D
arxiv created 2008/04/07 · openalex publication_date 2008/06/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Pulsars in close binary systems with white dwarfs or other neutron stars make ideal laboratories for testing the predictions of gravitational radiation and self-gravitational effects. We report new timing measurements of the pulsar--white-dwarf binary PSR J1141--6545. The orbit is found to be decaying at a rate of 1.04\ifmmode±\else\textpm\fi0.06 times the general relativistic prediction and the Shapiro delay is consistent with the orbital inclination angle derived from scintillation measurements. The system provides a unique testbed for tensor-scalar theories of gravity. Our measurements place stringent constraints in the theory space, with a limit of \ensuremathα02<2.1\ifmmode×\else\texttimes\fi10^\ensuremath-5 for weakly nonlinear coupling and an asymptotic limit of \ensuremathα02<3.4\ifmmode×\else\texttimes\fi10^\ensuremath-6 for strongly nonlinear coupling (where \ensuremathα0 is the linear coupling strength of matter to an underlying scalar field), which is nearly 3 times smaller than the Cassini bound (\ensuremathα02\ensuremath≈10^\ensuremath-5).