4 research outputs found
Cosmological dynamics of the general non-canonical scalar field models
We extend the investigation of cosmological dynamics of the general
non-canonical scalar field models by dynamical system techniques for a broad
class of potentials and coupling functions. In other words, we do not restrict
the analysis to exponential or power-law potentials and coupling functions.
This type of investigation helps in understanding the general properties of a
class of cosmological models. In order to better understand the phase space of
the models, we investigate the various special cases and discuss the stability
and viability issues. Performing a detailed stability analysis, we show that it
is possible to describe the cosmic history of the universe at the background
level namely the early radiation dominated era, intermediate matter dominated
era and the late time dark energy domination. Moreover, we find that we can
identify a broad class of coupling functions for which it is possible to get an
appealing unified description of dark matter and dark energy. The results
obtained here, therefore, enlarge the previous analyses wherein only a specific
potential and coupling functions describes the unification of dark sectors.
Further, we also observe that a specific scenario can also possibly explain the
phenomenon of slow-roll inflationary exit.Comment: Revised to match EPJC version; 12 pages, 6 figures; Accepted in EPJ
Extended Phase Space Analysis of Interacting Dark Energy Models in Loop Quantum Cosmology
International audienceThe present work deals with the dynamical system investigation of interacting dark energy models (quintessence and phantom) in the framework of loop quantum cosmology by taking into account a broad class of self-interacting scalar field potentials. The main reason for studying potentials beyond the exponential type is to obtain additional critical points which can yield more interesting cosmological solutions. The stability of critical points and the asymptotic behavior of the phase space are analyzed using dynamical system tools and numerical techniques. We study two classes of interacting dark energy models and consider two specific potentials as examples: the hyperbolic potential and the inverse power-law potential. We find a rich and interesting phenomenology, including the avoidance of big rip singularities due to loop quantum effects, smooth and nonlinear transitions from matter domination to dark energy domination, and finite periods of phantom domination with dynamical crossing of the phantom barrier