Constraining alternative theories of gravity by gravitational waves from precessing eccentric compact binaries with LISA
Abstract
We calculate how strongly one can put constraints on alternative theories of gravity such as Brans-Dicke and massive graviton theories with LISA. We consider inspiral gravitational waves from a compact binary composed of a neutron star and an intermediate mass black hole in Brans-Dicke (BD) theory and that composed of a super massive black hole in massive graviton theories. We use the restricted second post-Newtonian waveforms including the effects of spins. We also take both precession and eccentricity of the orbit into account. For simplicity, we set the fiducial value for the spin of one of the binary constituents to zero so that we can apply the approximation called simple precession. We perform the Monte Carlo simulations of 104 binaries, estimating the determination accuracy of binary parameters including the BD parameter ωBD and the Compton wavelength of graviton λg for each binary using the Fisher matrix method. We find that including both the spin-spin coupling σ and the eccentricity e into the binary parameters reduces the determination accuracy by an order of magnitude for the Brans-Dicke case, while it has less influence on massive graviton theories. On the other hand, including precession enhances the constraint on ωBD only 20% but it increases the constraint on λg by several factors. Using a (1.4+1000)M⊙ neutron star/black hole binary of SNR=200, one can put a constraint ωBD>6944, while using a (107+106)M⊙ black hole/black hole binary at 3 Gpc, one can put λg>3.10×1021cm, on average. The latter is 4 orders of magnitude stronger than the one obtained from the solar system experiment. These results are consistent with previous results within uncontrolled errors and indicate that the effects of precession and eccentricity must be taken carefully in the parameter estimation analysis.
- Publication:
-
Physical Review D
- Pub Date:
- March 2010
- DOI:
- 10.1103/PhysRevD.81.064008
- arXiv:
- arXiv:0906.4269
- Bibcode:
- 2010PhRvD..81f4008Y
- Keywords:
-
- 04.30.Db;
- 04.80.Cc;
- Wave generation and sources;
- Experimental tests of gravitational theories;
- General Relativity and Quantum Cosmology;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 35 pages, 17 figures