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 $M\sim 10\mathrm{TeV}$ opens up for light primordial dark matter. A new dedicated experimental program is needed to test this mass range of primordial dark matter.

• Received 22 February 2018

DOI:https://doi.org/10.1103/PhysRevD.97.123520

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society