High Energy Physics Seminar
The conventional misalignment mechanism can explain axion dark matter only in a limited mass range and face various difficulties for vector dark matter that we refer to as dark photons. For the former case, we provide a dynamical explanation for an initial condition near the hilltop or the bottom of the potential, which allows for a much wider mass range. Additionally, we propose new dark matter production mechanisms for axions and dark photons via parametric resonance and tachyonic instability, respectively. These ideas expand the parameter space to the regions of interest for the extensive experimental searches.