Light Primordial Exotic Compact Objects as All Dark Matter

TL;DR

This paper explores the possibility that light primordial exotic compact objects, which emit suppressed radiation compared to black holes, could constitute all dark matter below a certain mass, opening new experimental avenues.

Contribution

It reevaluates constraints on light ECOs as dark matter candidates and identifies a large new parameter space for masses down to 10 TeV.

Findings

Light ECOs could make up all dark matter below 10^{-16} solar masses.

Existing constraints leave a large unexplored parameter space for ECO masses around 10 TeV.

A new experimental program is required to test this primordial dark matter hypothesis.

Abstract

The radiation emitted by horizonless exotic compact objects (ECOs), such as wormholes, 2-2-holes, fuzzballs, gravastars, boson stars, collapsed polymers, superspinars etc., is expected to be strongly suppressed when compared to the radiation of black holes. If large primordial curvature fluctuations collapse into such objects instead of black holes, they do not evaporate or evaporate much slower than black holes and could thus constitute all of the dark matter with masses below $M < 10^{-16}M_\odot.$ We reevaluate the relevant experimental constraints for light ECOs in this mass range and show that very large new parameter space down to ECO masses $M\sim 10\,{\rm TeV}$ opens up for light primordial dark matter. A new dedicated experimental program is needed to test this mass range of primordial dark matter.