The two-component formalism in quantum cosmology is revisited with a particular emphasis on the identification of time. Its relation with the appearance of imaginary eigenvalues is established. It is explicitly shown how ...

The Einstein equations for an isotropic and homogeneous Friedmann-Robertson-Walker universe in the presence of a quintessence scalar field are shown to be described in a compact way, formally identical to the dynamics of ...

The question of the origin of the universe is an ancient one, yet science has had the tools to search for a proper answer for only the last hundred years or so. Over the last fifty years there has been an increasing interest ...

The dynamics of the most general Bianchi IX cosmology with three time dependent scale factors for the Einstein-Skyrme system are analyzed. For the Skyrmion, a generalized hedgehog ansatz with unit baryon charge is introduced. ...