https://doi.org/10.1140/epjc/s10052-020-8183-4
Regular Article - Theoretical Physics
Waves from the centre: probing PBH and other macroscopic dark matter with LISA
1
Department of Physics, The Oskar Klein Centre for Cosmoparticle Physics, Stockholm University, AlbaNova University Centre, Roslagstullsbacken 21, 106 91, Stockholm, Sweden
2
Max Planck Institute for Gravitational Physics (Albert Einstein Institute), D-14476, Potsdam-Golm, Germany
3
CERCA/ISO, Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
4
Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA
* e-mail: andrew.matas@aei.mpg.de
Received:
14
April
2020
Accepted:
24
June
2020
Published online:
15
July
2020
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 
–
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 
, if a dark-matter spike of the type originally predicted by Gondolo and Silk forms near the central black hole.
© The Author(s), 2020
