Speaker
Description
Atomic dark matter (aDM) is a simple but highly theoretically motivated possibility for an interacting dark sector that could constitute some or all of dark matter. We perform a comprehensive study of precision cosmological observables on minimal atomic dark matter, exploring for the first time the full parameter space of dark QED coupling and dark electron and proton masses ($\alpha_{D},m_{e_{D}},m_{p_{D}}$) as well as the two cosmological parameters of aDM mass fraction $f_{D}$ and temperature ratio $\xi$ at the time of SM recombination. We also show how aDM can alleviate the ($H_{0}$, $S_{8}$) tension from late-time measurements, leading to a significantly better fit than $\Lambda$CDM or $\Lambda$CDM + dark radiation. Furthermore, including late-time measurements leads to strikingly tight constraints on the parameters of atomic dark matter. An aDM fraction $f_{D} > 0.1$ is preferred, with a dark recombination around $z=2\times 10^{4}$.
