Axino dark matter from Q-balls in Affleck-Dine baryogenesis and the Omega b-Omega DM 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 TR must be low, some 10(2) GeV, or less.