scholarly journals Growth of massive black hole seeds by migration of stellar and primordial black holes: gravitational waves and stochastic background

2021 ◽  
Vol 2021 (10) ◽  
pp. 035
Author(s):  
Lumen Boco ◽  
Andrea Lapi ◽  
Alex Sicilia ◽  
Giulia Capurri ◽  
Carlo Baccigalupi ◽  
...  
2021 ◽  
Author(s):  
Rui feng Zheng ◽  
Jia ming Shi ◽  
Taotao Qiu

Abstract It is well known that primordial black hole (PBH) can be generated in inflation process of the early universe, especially when the inflaton field has some non-trivial features that could break the slow-roll condition. In this paper, we investigate a toy model of inflation with bumpy potential, which has one or several bumps. We found that potential with multi-bump can give rise to power spectra with multi peaks in small-scale region, which can in turn predict the generation of primordial black holes in various mass ranges. We also consider the two possibilities of PBH formation by spherical collapse and elliptical collapse. And discusses the scalar-induced gravitational waves (SIGWs) generated by the second-order scalar perturbations.


Author(s):  
Florian Kühnel ◽  
Andrew Matas ◽  
Glenn D. Starkman ◽  
Katherine Freese

Abstract A significant fraction of cosmological dark matter can be formed by very dense macroscopic objects, for example primordial black holes. Gravitational waves offer a promising way to probe these kinds of dark-matter candidates, in a parameter space region that is relatively untested by electromagnetic observations. In this work we consider an ensemble of macroscopic dark matter with masses in the range $$10^{-13}$$10-13–$$1\ M_{\odot }$$1M⊙ orbiting a super-massive black hole. While the strain produced by an individual dark-matter particle will be very small, gravitational waves emitted by a large number of such objects will add incoherently and produce a stochastic gravitational-wave background. We show that LISA can be a formidable machine for detecting the stochastic background of such objects orbiting the black hole in the centre of the Milky Way, Sgr $$\mathrm{A}^{\!*}$$A∗, if a dark-matter spike of the type originally predicted by Gondolo and Silk forms near the central black hole.


2021 ◽  
pp. 100836
Author(s):  
Andrew L. Miller ◽  
Sébastien Clesse ◽  
Federico De Lillo ◽  
Giacomo Bruno ◽  
Antoine Depasse ◽  
...  

Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 372-378
Author(s):  
Viktor D. Stasenko ◽  
Alexander A. Kirillov

In this paper, the merger rate of black holes in a cluster of primordial black holes (PBHs) is investigated. The clusters have characteristics close to those of typical globular star clusters. A cluster that has a wide mass spectrum ranging from 10−2 to 10M⊙ (Solar mass) and contains a massive central black hole of the mass M•=103M⊙ is considered. It is shown that in the process of the evolution of cluster, the merger rate changed significantly, and by now, the PBH clusters have passed the stage of active merging of the black holes inside them.


2018 ◽  
Vol 191 ◽  
pp. 07003
Author(s):  
Xavier Calmet ◽  
Boris Latosh

We show that alongside the already observed gravitational waves, quantum gravity predicts the existence of two additional massive classical fields and thus two new massive waves. We set a limit on their masses using data from Eöt-Wash-like experiments. We point out that the existence of these new states is a model independent prediction of quantum gravity. We explain how these new classical fields could impact astrophysical processes and in particular the binary inspirals of black holes. We calculate the emission rate of these new states in binary inspirals astrophysical processes.


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