2020/07/31 by Vicente Atal, Albert Sanglas, Nikolaos Triantafyllou
Physics and Astronomy · #Binary black hole #Binary number #Cluster analysis #Cosmology and Gravitation Theories #Dark matter #Degeneracy (biology) #Gravitational wave #LIGO #Primordial black hole #Pulsars and Gravitational Waves Research #Scientific Research and Discoveries #astro-ph.CO #gr-qc
paper · pdf · doi:10.1088/1475-7516/2020/11/036
23 pages, 6 figures. v2: refs added, small changes. v3: Fig. 6 corrected, conclusions unchanged
openalex created_date 2020/07/23 · openalex publication_date 2020/11/19 · arxiv created 2020/12/14 · arxiv updated 2020/12/15 · openalex updated_date 2026/08/08
We discuss the effect of clustering for the determination of the merger rate of binary black holes in the LIGO/Virgo mass range. While for a Poissonian initial distribution, and assuming isolated binaries, the allowed fraction of Primordial Black Holes (PBHs) to dark matter (DM) is a few percent, we show that this bound can be relaxed if PBHs are clustered. More precisely we show that for large clustering the merger rate can drop with increasing fraction of PBHs, introducing a degeneracy in the parameters of the theory consistent with a given present merger rate, and allowing all the DM to be in the form of stellar mass PBHs. This degeneracy can however be broken by looking at the evolution of the merger rate with redshift. For a simple clustering model that we consider, we show that the LIGO/Virgo projected sensitivity can disentangle, through the observation of a stochastic background of gravitational waves, different clustered distributions having the same present merger rate.