GW emission and relativistic dynamical friction in intermediate mass ratio inspirals

Abstract

We present a set of preliminary simulations of intermediate mass ratio inspirals (IMRIs) inside dark matter (DM) spikes accounting for post-Newtonian corrections the interaction between the two black holes up to the order 2.5 in $c^2$, as well as relativistic corrections to the dynamical friction (DF) force exerted by the DM distribution. We find that, incorporating relativity reduces of a factor $1/2$ the inspiral time, for equivalent initial orbital parameters, with respect to the purely classical estimates. Vice versa, neglecting the DF of the spike systematically yields longer inspiral times.

arXiv comment4 pages, 2 figures. To appear in the proceedings of the 398 IAU symposium "MODEST-Compact Stars and Binaries in Dense Star Clusters"