2-field model of dark energy with canonical and non-canonical kinetic terms

Abstract

We generalize quintom to include the tachyonic kinetic term along with the classical one. For such a model we obtain the expressions for energy density and pressure. For the spatially flat, homogeneous and isotropic Universe with Friedmann-Robertson-Walker metric of 4-space we derive the equations of motion for the fields. We discuss in detail the reconstruction of the scalar fields potential $U(\phi,\xi)$. Such a reconstruction cannot be done unambiguously, so we consider 3 simplest forms of $U(\phi,\xi)$: the product of $\Phi(\phi)$ and $\Xi(\xi)$, the sum of $\Phi(\phi)$ and $\Xi(\xi)$ and this sum to the $\kappa$th power.