Superheavy dark matter in $R^2$-cosmology

TL;DR

This paper explores how modifications to the standard cosmological model, specifically in $R^2$-cosmology, can produce superheavy stable particles that match observed dark matter densities, addressing tensions in conventional cosmology.

Contribution

It demonstrates that in $R^2$-cosmology, superheavy stable particles can be generated with correct relic densities, providing a potential solution to dark matter production issues.

Findings

Superheavy particles can be produced with observed dark matter density.

Modified cosmology allows creation of particles heavier than several TeV.

GUT SUSY coupling strength is sufficient for particle production.

Abstract

The conventional Friedmann cosmology is known to be in tension with the existence of stable particles having interaction strength typical for supersymmetry and heavier than several TeV. A possible way to save life of such particles may be a modification of the standard cosmological expansion law in such a way that the density of these heavy relics would be significantly reduced. We study particle creation in the Starobinsky inflationary model for different decay channels of the scalaron. It is shown that in the process of thermalization superheavy stable particles with the coupling strength typical for the GUT SUSY could be created with the density equal to the observed density of dark matter.