Positrons from Primordial Black Hole Microquasars and Gamma-ray Bursts

TL;DR

This paper explores how primordial black holes captured by compact stars can produce gamma-ray bursts and microquasars, potentially explaining positron excesses observed in cosmic ray experiments.

Contribution

It introduces novel scenarios linking primordial black holes to gamma-ray bursts, microquasars, and positron flux, combining astrophysical and dark matter perspectives.

Findings

Primordial black holes can produce observable gamma-ray bursts and microquasars.

Captured PBHs may significantly contribute to cosmic positron excess.

Relativistic jets from these systems accelerate positrons to high energies.

Abstract

We propose several novel scenarios how capture of small sublunar-mass primordial black holes (PBHs) by compact stars, white dwarfs or neutron stars, can lead to distinct short gamma-ray bursts (sGRBs) as well as microquasars (MQs). In addition to providing new signatures, relativistic jets from these systems will accelerate positrons to high energies. We find that if PBHs constitute a sizable fraction of DM, they can significantly contribute to the excess observed in the positron flux by the Pamela, the AMS-02 and the Fermi-LAT experiments. Our proposal combines the beneficial features of astrophysical sources and dark matter.