Quasicircular inspirals and plunges from nonspinning effectiveonebody Hamiltonians with gravitational selfforce information
Abstract
The selfforce program aims at accurately modeling relativistic twobody systems with a small mass ratio (SMR). In the context of the effectiveonebody (EOB) framework, current results from this program can be used to determine the effective metric components at linear order in the mass ratio, resumming postNewtonian (PN) dynamics around the testparticle limit in the process. It was shown in [Akcay et al., Phys. Rev. D 86, 104041 (2012)., 10.1103/PhysRevD.86.104041] that, in the original (standard) EOB gauge, the SMR contribution to the metric component g_{t}^{t eff} exhibits a coordinate singularity at the lightring (LR) radius. In this paper, we adopt a different gauge for the EOB dynamics and obtain a Hamiltonian that is free of poles at the LR, with complete circularorbit information at linear order in the mass ratio and noncircularorbit and higherorderinmassratio terms up to 3PN order. We confirm the absence of the LR divergence in such an EOB Hamiltonian via plunging trajectories through the LR radius. Moreover, we compare the binding energies and inspiral waveforms of EOB models with SMR, PN and mixed SMR3PN information on a quasicircular inspiral against numericalrelativity predictions. We find good agreement between numericalrelativity simulations and EOB models with SMR3PN information for both equal and unequalmass ratios. In particular, when compared to EOB inspiral waveforms with only 3PN information, EOB Hamiltonians with SMR3PN information improves the modeling of binary systems with small mass ratios q ≲1 /3 , with a dephasing accumulated in ∼30 gravitationalwave (GW) cycles being of the order of few hundredths of a radian up to 4 GW cycles before merger.
 Publication:

Physical Review D
 Pub Date:
 January 2020
 DOI:
 10.1103/PhysRevD.101.024024
 arXiv:
 arXiv:1907.11597
 Bibcode:
 2020PhRvD.101b4024A
 Keywords:

 General Relativity and Quantum Cosmology
 EPrint:
 16 pages, 5 figures