Gravitational Radiation, Close Binary Systems, and the Brans-Dicke Theory of Gravity
Abstract
Observational limits on the orbital period change of the binary pulsar PSR 1913+16 and of the 11-minute binary system 4U1820-30 are used to constrain the Brans-Dicke scalar-tensor theory of gravity. In 4U1820-30, dipole gravitational radiation damping is important. The conservative bound on the Brans-Dicke coupling constant is found to be omega(BD) greater than 30. The bounds are sensitive to the neutron-star model used and to the masses of the stars: for masses of 1.4 solar and 0.067 solar the bounds are omega(BD) greater than 140 for a stiff equation of state and omega(BD) greater than 600 for a soft equation of state. The binary pulsar differences between the Brans-Dicke theory and general relativity are suppressed by a factor related to the gravitational energy of the neutron stars, so that the resulting constraint on omega(BD) is uninteresting.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1989
- DOI:
- 10.1086/168016
- Bibcode:
- 1989ApJ...346..366W
- Keywords:
-
- Binary Stars;
- Computational Astrophysics;
- Gravitation Theory;
- Gravitational Waves;
- Neutron Stars;
- Pulsars;
- Relativity;
- Black Holes (Astronomy);
- Equations Of State;
- Mass Transfer;
- Scalars;
- Tensors;
- Astrophysics;
- GRAVITATION;
- PULSARS;
- STARS: BINARIES;
- STARS: INDIVIDUAL ALPHANUMERIC: PSR 1913;
- 16;
- STARS: INDIVIDUAL ALPHANUMERIC: 4U 1820-30;
- STARS: NEUTRON