Complete cosmic scenario in the Randall-Sundrum braneworld from the dynamical systems perspective

The paper deals with dynamical system analysis of a coupled scalar field in the Randall-Sundrum(RS)2 brane world. The late time attractor describes the final state of the cosmic evolution. In RS2 based phantom model there is no late-time attractor and consequently there is uncertainty in cosmic evolution. In this paper, we have shown that it is possible to get late-time attractor when gravity is coupled to scalar field. Finally, in order to predict the final evolution of the universe, we have also studied classical stability of the model. It is found that there are late time attractors which are both locally as well as classically stable and so our model can realise the late time cosmic acceleration.Comment: 18 pages, 9 figures, Publishe

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