|Modelling a Circular Equatorial Test-particle in a Kerr Spacetime
|467, 9th LISA Symposium
|Carré, J.; Porter, E. K.
|Extreme mass ratio inspirals are one of the principal sources of gravitational waves for future space-based detectors. They are interesting sources as they allow us to better understand the spacetime around a black hole. In order to measure the system parameters with high accuracy we need to have a very good model of the gravitational wave (GW) flux. For a test-pariticle, we use a post-newtonian (PN) approximation of the GW flux which is known up to 4 PN for the Kerr case, and up to 5.5 PN for the Schwarzschild case. The problem is that the PN series is asymptotically divergent. To improve the convergence of the series, re-summation methods such as Padé and Chebyshev approximations have been proposed.
In this work we investigate to use a more complete post-newtonian flux, where we add the 5.5 PN Schwarzschild terms to the 4 PN Kerr terms. We also take into account the absorption of gravitational waves by the central black hole up to 5.5PN. We then compare this new flux with numerical fluxes using different re-summation methods for different spins and PN orders.