Recycled Dark Matter

TL;DR

This paper proposes a novel dark matter production mechanism called "recycling" involving false vacuum pockets collapsing into primordial black holes that evaporate before BBN, producing ultra heavy dark matter particles.

Contribution

It introduces a new mechanism for generating ultra heavy dark matter via false vacuum pockets and primordial black hole evaporation, with controllable mass functions.

Findings

Mechanism produces UHDM with correct relic density.

Dark sector includes multiple decoupled species.

PBH mass functions are tunable via IR operators.

Abstract

We outline a new production mechanism for dark matter that we dub "recycling": dark sector particles are kinematically trapped in the false vacuum during a dark phase transition; the false pockets collapse into primordial black holes (PBHs), which ultimately evaporate before Big Bang Nucleosynthesis (BBN) to reproduce the dark sector particles. The requirement that all PBHs evaporate prior to BBN necessitates high scale phase transitions and hence high scale masses for the dark sector particles in the true vacuum. Our mechanism is therefore particularly suited for the production of ultra heavy dark matter (UHDM) with masses above $\sim 10^{12}\,{\rm GeV}$. The correct relic density of UHDM is obtained because of the exponential suppression of the false pocket number density. Recycled UHDM has several novel features: the dark sector today consists of multiple decoupled species that were once in thermal equilibrium and the PBH formation stage has extended mass functions whose shape can be controlled by IR operators coupling the dark and visible sectors.