Black hole mergers, gravitational waves and scaling relations

Abstract

Observations of gravitational waves provide new opportunities to study our Universe. In particular, mergers of stellar black holes are the main targets of the current gravitational wave experiments. In order to make accurate predictions, it is however necessary to simulate the mergers in numerical general relativity, which requires high performance computing. Yet numerical simulation codes are optimized for specific mass scales, and may not be adapted to the study of other mass scales. In particular, primordial black holes can have masses ranging from the Planck mass to millions of solar masses, and simulations of primordial black hole mergers over the whole mass range are currently beyond the capabilities of the numerical codes. In this letter, we derive scaling relations, which can be used to rescale simulations of stellar black hole mergers and gravitational waves to any mass scale, hence allowing to perform precise simulations at any mass scale. In addition we study the domain of validity of the rescaling.

Dark matter and the early Universe: A review

“…Basically, the masses of dark matter candidates span the whole range between 10 −24 eV and millions of solar masses. Primordial black holes [33][34][35] for example have attracted interest after the discovery of gravitational waves by LIGO and Virgo [36], especially because they can be used as probes for gravity [37][38][39][40], for quantum effects through their evaporation [41][42][43][44] and for primordial Universe models [33,[45][46][47][48]. In the following, in order to discuss the relation between early Universe and dark matter, we will focus on particle physics candidates.…”

Precision Calculation of Dark Radiation from Spinning Primordial Black Holes and Early Matter Dominated Eras

“…Ref. [65] has studied different timescales which are relevant to mergers in a population of PBHs in early Universe. The merger rate could be enhanced if PBHs form in clusters, a hypothesis that will be testable in future experiments looking for CMB µ-distortion, as proposed recently [66].…”