Dark Matter Inelastic Up-Scattering with the Interstellar Plasma: An Exciting New Source of X-Ray Lines, including at 3.5 keV

Francesco D'Eramo, Kevin Hambleton, Stefano Profumo +1

We explore the phenomenology of a class of models where the dark matter particle can inelastically up-scatter to a heavier excited state via off-diagonal dipolar interactions with…