Primordial-black-hole mergers in dark-matter spikes [CEA]

http://arxiv.org/abs/1708.08449


It has been suggested that primordial black holes (PBHs) of roughly 30 solar masses could make up the dark matter and if so, might account for the recent detections by LIGO involving binary black holes in this mass range. It has also been argued that the supermassive black holes (SMBHs) that reside at galactic centers may be surrounded by extremely-dense dark-matter spikes. Here we show that the rate for PBH mergers in these spikes may well exceed the merger rate, considered before, in galactic dark-matter halos, and may provide a plausible explanation for the current rate of detection of mergers of 30-solar-mass black holes, even if PBHs make up a subdominant contribution to the dark matter. The gravitational-wave signals from such events will always originate in galactic centers, as opposed to those from halos, which are expected to have little correlation with luminous- galaxy positions.

Read this paper on arXiv…

H. Nishikawa, E. Kovetz, M. Kamionkowski, et. al.
Wed, 30 Aug 2017
38/67

Comments: 6 pages, 4 figures