1207.6691 (M. Sami et al.)

Cosmological dynamics of non-minimally coupled scalar field system and
its late time cosmic relevance    [PDF]

M. Sami, M. Shahalam, M. Skugoreva, A. Toporensky

We investigate the cosmological dynamics of non-minimally coupled scalar field system described by $F(\phi)R$ coupling with $F(\phi)=(1-\xi\phi^N)R$($N\ge2$) and the field potential, $V(\phi)=V_0\phi^n$. We use a generic set of dynamical variables to bring out new asymptotic regimes of the underlying dynamics. However, our dynamical variables miss the most important fixed point$-$ the de Sitter solution. We make use of the original form of system of equations to investigate the issues related to this important solution. In particular, we show that the de-Sitter solution which is a dynamical attractor of the system lies in the region of negative effective gravitational constant $G_N$ thereby leading to a ghost dominated universe in future and a transient quintessence(phantom) phase with $G_N>0 $ at present. We also carry out comparison of the model with other competing models of dark energy such as galileon modified gravity and others.

View original: http://arxiv.org/abs/1207.6691