Evolution of primordial dark matter planets in the early Universe

In a recent paper we had discussed possibility of DM at high redshifts forming primordial planets composed entirely of DM to be one of the reasons for not detecting DM (as the flux of ambient DM particles would be consequently reduced). In this paper we discuss the evolution of these DM objects as the Universe expands. As Universe expands there will be accretion of DM, helium and hydrogen layers (discussed in detail) on these objects. As they accumulate more and more mass, the layers get heated up leading to nuclear reactions which burn H and He when a critical thickness is reached. In the case of heavier masses of these DM objects, matter can be ejected explo-sively. It is found that the time scale of ejection is smaller than those from other compact objects like neutron stars (that lead to x-ray bursts). These flashes of energy could be a possible observational signature for these dense DM objects. (C) 2021 COSPAR. Published by Elsevier B.V. All rights reserved.

Automated summary

In this paper, the authors discuss the possibility of primordial planets composed entirely of dark matter at high redshifts and their evolution as the Universe expands. These dark matter objects accrete helium and hydrogen layers, leading to nuclear reactions and potentially explosive matter ejection. The time scale of ejection from these dense dark matter objects is found to be shorter than that of other compact objects like neutron stars.