Has LIGO detected primordial black hole dark matter?——tidal disruption in binary black hole formation  

作　　者：Yuan Gao Xiao-Jia Zhang Meng Su 

机构地区：[1]Department of Physics,The University of Hong Kong,Hong Kong SAR,China [2]Department of Earth Sciences,The University of Hong Kong,Hong Kong SAR,China [3]Department of Physics and Laboratory for Space Research,The University of Hong Kong,Hong Kong SAR,China

出　　处：《Research in Astronomy and Astrophysics》2020年第11期303-311,共9页天文和天体物理学研究（英文版）

摘　　要：The frequent detection of binary mergers of^30 M⊙black holes(BHs)by the Laser Interferometer Gravitational-Wave Observatory(LIGO)rekindled researchers’interest in primordial BHs(PBHs)being dark matter(DM).In this work,we investigated PBHs distributed as DM with a monochromatic mass of 30 M⊙and examined the encounter-capture scenario of binary formation,where the densest central region of DM halo dominates.Thus,we paid special attention to the tidal effect by the supermassive black hole(SMBH)present.In doing so,we discovered a necessary tool called loss zone that complements the usage of loss cone.We found that the tidal effect is not prominent in affecting binary formation,which also turned out to be insufficient in explaining the totality of LIGO’s event rate estimation,especially due to a microlensing event constraining the DM fraction in PBH at the mass of interest from near unity to an order smaller.Meanwhile,an early-universe binary formation scenario proves so prevailing that the LIGO signal in turn constrains the PBH fraction below one percent.Thus,people should put more faith in alternative PBH windows and other DM candidates.

关 键 词：black hole physics dark matter gravitational waves QUASARS supermassive black holes 

分 类 号：P14[天文地球—天体物理]