Ultra High Energy Cosmic Rays from decays of Holeums in Galactic Halos

TL;DR

This paper proposes that decayed Holeums, stable bound states of primordial black holes, in galactic halos could explain ultra high energy cosmic rays and their properties, including the absence of the GZK cut-off.

Contribution

It introduces Holeums as stable dark matter candidates and links their decay to the origin of ultra high energy cosmic rays, explaining observed phenomena.

Findings

Holeums of 10^13 to 10^14 GeV are stable today.

Decay of Holeums can produce cosmic rays across all observed energies.

The model accounts for the absence of the GZK cut-off in cosmic ray spectrum.

Abstract

Stable, quantized gravitational bound states of primordial black holes called Holeums could have been produced in the early universe and could be a component of the Super Heavy Dark Matter (SHDM) present in galactic halos. We show that Holeums of masses of the order of 10**13 to 10**14 GeV and above are stable enough to survive in the present-day universe. We identify such Holeums as promising candidates for the SHDM "X-particle" and show that the decay of such Holeums by pressure ionization can give rise to cosmic rays of all observed energies, including Ultra High Energy Cosmic Rays (UHECR). The absence of the GZK cut-off is explained by the galactic halo origin of the UHECR. We predict that the cosmic rays are a manifestation of the end-stage Hawking radiation burst of the primordial black holes (PBH) liberated by the ionization of Holeums. Antimatter detected in cosmic rays could be a signature of their Holeum origin.