Speaker
Description
We propose a paradigm where the QCD axion’s unexplored cosmological evolution, a rotation in the field space, gives rise to dark matter, the baryon asymmetry, and/or gravitational waves. The rotation is initiated by explicit Peccei-Quinn (PQ) symmetry breaking effective in the early Universe. The abundance of axion dark matter is determined by the rotational speed via what we call kinetic misalignment. With the aid of the Standard Model sphaleron processes (and potentially the neutrino Majorana mass term), the PQ charge associated with the rotation is transferred to the baryon asymmetry. We name these baryogenesis mechanisms by axiogenesis (and lepto-axiogenesis). The paradigm predicts 1) an axion coupling stronger than the conventional ones and 2) an electroweak phase transition earlier than predicted by the Standard Model (or instead the presence of the neutrino Majorana mass). If the axion couples to a dark photon, this new axion dynamics can also generate gravitational wave signals across the observable frequencies.
