Exploring multimessenger signals from heavy dark matter decay with EDGES 21-cm result and IceCube

Abstract

The primordial heavy or superheavy dark matter that could be created during the reheating or preheating stage of the Universe can undergo QCD cascade decay process to produce leptons or gamma as end products. Although these could be rare decays, the energy involved in such decay process can influence 21cm signal of hyperfine transition of neutral hydrogen during the reionization era. We explore in this work, possible multimessenger signals of such heavy dark matter decays.One of which could be the source of ultra high energy neutrino (of ∼ PeV energy regime) signals at IceCube detector whereas the other signal attributes to the cooling/heating of the baryons by the exchange of energy involved in this decay process and its consequent influence on 21cm signal. The effect of evaporation of primordial black holes and baryon scattering with light cold dark matter are also included in relation to the 21cm signal temperature and their influence are also discussed.

Two-component millicharged dark matter and the EDGES 21 cm signal *

“…which is about a factor of two larger than the value expected in the standard cosmology [4,5]. This hints that either the cosmic microwave background (CMB) could be hotter than expected [6][7][8][9], or the hydrogen gas could be colder than expected [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”