Dark Photon Limits from Patchy Dark Screening of the Cosmic Microwave Background.

Dark photons that kinetically mix with the Standard Model photon give rise to new spectral anisotropies (patchy dark screening) in the cosmic microwave background (CMB) due to conversion of photons to dark photons within large-scale structure. We utilize predictions for this patchy dark screening signal to provide the tightest constraints to date on the dark photon kinetic mixing parameter [ϵ≲4.5×10^{-8} (95% confidence level)] over the mass range 10^{-13}  eV≲m_{A^{'}}≲10^{-11}  eV, almost an order of magnitude stronger than previous limits, by applying state-of-the-art component separation techniques to the cross-correlation of Planck CMB and unWISE galaxy survey data.

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

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.

Strong Bound on Canonical Ultralight Axion Dark Matter from the Lyman-Alpha Forest.

We present a new bound on the ultralight axion (ULA) dark matter mass m_{a}, using the Lyman-alpha forest to look for suppressed cosmic structure growth: a 95% lower limit m_{a}>2×10^{-20}  eV. This strongly disfavors (>99.7% credibility) the canonical ULA with 10^{-22}  eV View Article and Find Full Text PDF