Limits on the Light Dark Matter-Proton Cross Section from Cosmic Large-Scale Structure

Keir K Rogers; Cora Dvorkin; Hiranya V Peiris

doi:10.1103/PhysRevLett.128.171301

Limits on the Light Dark Matter-Proton Cross Section from Cosmic Large-Scale Structure

Phys Rev Lett. 2022 Apr 29;128(17):171301. doi: 10.1103/PhysRevLett.128.171301.

Authors

Keir K Rogers¹, Cora Dvorkin², Hiranya V Peiris^{3

4}

Affiliations

¹ Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario M5S 3H4, Canada.
² Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
³ Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
⁴ Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, AlbaNova University Center, Stockholm 10691, Sweden.

PMID: 35570432
DOI: 10.1103/PhysRevLett.128.171301

Abstract

We set the strongest limits to date on the velocity-independent dark matter (DM)-proton cross section σ for DM masses m=10 keV to 100 GeV, using large-scale structure traced by the Lyman-alpha forest: e.g., a 95% lower limit σ<6×10^{-30} cm^{2}, for m=100 keV. Our results complement direct detection, which has limited sensitivity to sub-GeV DM. We use an emulator of cosmological simulations, combined with data from the smallest cosmological scales used to date, to model and search for the imprint of primordial DM-proton collisions. Cosmological bounds are improved by up to a factor of 25.