Avoiding parameter fine-tuning in mass varying neutrino models of DE?

Abstract

Coupled models of quintessence are usually introduced for avoiding or mitigating the parameter fine-tuning problem. At the same time, the coupled models should avoid the fine-tuning problem related to the initial conditions as quintessence models do. One more attractive feature of coupled models might be the explanation of the timescale at which the coincidence of DE and matter energy densities occur and the understanding of reason why after this the DE takes over. And finally, all these nice features should be unaffected by the quantum corrections of the potential. Having in mind these remarks, we shall focus our discussion on mass varying neutrino model of DE with inverse power-law potential to see how naturally does it work.