Crossing the phantom divide line from a generalized time-dependent Hubble parameter and its dynamical evolution a la Riccati

We introduce the notion of a generalized time-dependent Hubble parameter for the case of Friedmann-Robertson-Walker cosmology. We obtain a Riccati differential equation for the Hubble parameter, H, and it was observed that the effective equation of state in our framework can cross the phantom divide line as supported by recent astrophysical observations. In addition, the model is able to evolve without initial singularity.