Scalar Field as Dark Energy Accelerating Expansion of the Universe
arXiv:0805.3782 · doi:10.3103/S0884591308060019
Abstract
The features of a homogeneous scalar field $Ï$ with classical Lagrangian $L=Ï_{;i}Ï^{;i}/2-V(Ï)$ and tachyon field Lagrangian $L=-V(Ï)\sqrt{1-Ï_{;i}Ï^{;i}}$ causing the observable accelerated expansion of the Universe are analyzed. The models with constant equation-of-state parameter $w_{de}=p_{de}/Ï_{de}<-1/3$ are studied. For both cases the fields $Ï(a)$ and potentials $V(a)$ are reconstucted for the parameters of cosmological model of the Universe derived from the observations. The effect of rolling down of the potential $V(Ï)$ to minimum is shown.
14 pages, 14 figures, accepted for publication by Kinematics and Physics of Celestial Bodies (UA)