Methods to detect primordial black holes in astrophysics

Abstract

Primordial black holes may account for at least part of the dark matter present in the Universe. We study how primordial black holes might be observed through their impact on observable properties of a star formed at redshift z = 20 in a low-mass dark matter halo. An analytical expression is presented for the reshaping of primordial black holes' orbits assuming the star formation process as adiabatic. An enhanced density profile is obtained due to dark matter halo contraction in the innermost halo region. It is also discussed how this system might produce a LIGO event (10-100Hz). A long periodical signal is expected for MPBH 10 7 M if this system is inside the Milky Way.