Neutrino and Positron Constraints on Spinning Primordial Black Hole Dark Matter

TL;DR

This study investigates how the spin of primordial black holes affects their detectability through neutrino and positron signals, providing new constraints on their role as dark matter candidates.

Contribution

It offers a comprehensive analysis of the detectability of spinning primordial black holes via neutrino and positron observations, extending constraints to higher mass ranges.

Findings

Spinning primordial black holes are constrained up to higher masses than non-spinning ones.

Neutrino constraints are comparable but slightly weaker than gamma-ray bounds, offering robustness.

Positron constraints are stronger at higher masses for spinning black holes compared to non-spinning ones.

Abstract

Primordial black holes can have substantial spin -- a fundamental property that has a strong effect on its evaporation rate. We conduct a comprehensive study of the detectability of primordial black holes with non-negligible spin, via the searches for the neutrinos and positrons in the MeV energy range. Diffuse supernova neutrino background searches and observation of the 511 keV gamma-ray line from positrons in the Galactic center set competitive constraints. Spinning primordial black holes are probed up to a slightly higher mass range compared to non-spinning ones. Our constraint using neutrinos is slightly weaker than that due to the diffuse gamma-ray background, but complementary and robust. Our positron constraints are typically weaker in the lower mass range and stronger in the higher mass range for the spinning primordial black holes compared to the non-spinning ones. They are generally stronger than those derived from the diffuse gamma-ray measurements for primordial black holes having masses greater than a few $\times \, 10^{16}$g.