Axino dark matter from Q-balls in Affleck-Dine baryogenesis and the Ωb-ΩDM coincidence problem

We show that the Omega(b)-Omega(DM) coincidence can naturally be explained in a framework where axino is cold dark matter which is predominantly produced in nonthermal processes involving decays of Q-balls formed in Affleck-Dine baryogenesis. In this approach, the similarity of Omega(b) and Omega(DM) is a direct consequence of the (sub-)GeV scale of the mass of the axino, while the reheating temperature T-R must be low, some 10(2) GeV, or less.