Binary collisions of dark matter blobs

Abstract

We describe the model-independent mechanism by which dark matter and dark matter structures heavier than ~ 8 × 1011 GeV form binary pairs in the early Universe that spin down and merge both in the present and throughout the Universe’s history, producing potentially observable signals. Sufficiently dense dark objects will dominantly collide through binary mergers instead of random collisions. We detail how one would estimate the merger rate accounting for finite size effects, multibody interactions, and friction with the thermal bath. We predict how mergers of dark dense objects could be detected through gravitational and electromagnetic signals, noting that such mergers could be a unique source of high frequency gravitational waves. We rule out objects whose presence would contradict observations of the CMB and diffuse gamma-rays.

The effect of multiple cooling channels on the formation of dark compact objects

“…While ongoing searches for sub-solar mass black holes have not yielded any detections, the null detection of signals from sub-solar black holes can be used to put constraints on the model parameters of a dissipative dark sector [62]. In the future, both ground-based experiments such as the Einstein Telescope [63] and space-based experiments such as the Laser Interferometer Space Antenna (LISA) [64] are expected to be able to detect these exotic compact objects [39,[65][66][67]. However, to study the gravitational wave signatures of these exotic compact object binaries, more detailed calculations must be done to analyze the behaviour of the fragments after the end of fragmentation.…”