Misalignment Production of Vector Boson Dark Matter from Axion-Su(2) Inflation

We present a new mechanism to generate a coherently oscillating dark vectorfield from axion-SU(2) gauge field dynamics during inflation. The SU(2) gaugefield acquires a nonzero background sourced by an axion during inflation, andit acquires a mass through spontaneous symmetry breaking after inflation. Wefind that the coherent oscillation of the dark vector field can account fordark matter in the mass range of 10^-13-1 eV in a minimal setup. In a moreinvolved scenario, the range can be wider down to the fuzzy dark matter region.One of the dark vector fields can be identified as the dark photon, in whichcase this mechanism evades the notorious constraints for isocurvatureperturbation, statistical anisotropy, and the absence of ghosts that exist inthe usual misalignment production scenarios. Phenomenological implications arediscussed.