Bound states between dark matter particles and emission of gravitational radiation

TL;DR

This paper investigates gravitationally bound states of weakly interacting massive particles, calculating their extremely long lifetimes for gravitational radiation emission and annihilation, which far exceed the universe's age.

Contribution

It introduces the concept of WIMPonium formed via gravitational interaction and computes its decay lifetimes, highlighting their cosmological stability.

Findings

Lifetimes of gravitational radiation emission are vastly longer than the universe's age.

WIMPonium can form through gravitational attraction despite weak interactions being repulsive.

The study provides theoretical estimates for annihilation into gravitons.

Abstract

Bound states of two weakly interactive massive particles are studied. It is assumed that the WIMPonium is formed due to the gravitational interaction, since the weak interaction can sometimes be repulsive. The lifetimes of the spontaneous emission of gravitational radiation and of the WIMPs annihilation into a pair of gravitons are computed, and are shown to be many orders of magnitude larger than the age of the universe.