Neutrino Fluence influenced by Memory Burdened Primordial Black Holes

Abstract: Primordial black holes (PBHs), formed in the early Universe, are capable of emitting both Standard Model (SM) and beyond the Standard Model (BSM) particles via Hawking radiation. We investigate the impact of the recently proposed memory burden effect which is a quantum gravitational backreaction that suppresses black hole evaporation once approximately half the PBH mass is lost on the production of high energy neutrinos. In particular, we examine how this suppression modifies the time-integrated muon neutrino flux, with and without the inclusion of heavy neutral leptons (HNLs) as BSM states. We compute the resulting neutrino fluence for different suppression strengths and analyze the prospects for detection in neutrino telescopes such as IceCube. Our results show that the memory burden significantly alters the neutrino energy spectrum, particularly at high energies, and that the presence of HNLs can counterbalance this suppression by introducing additional neutrino production channels. These findings have important implications for the detectability of PBH evaporation signatures and the parameter space of HNLs in cosmological settings.