A study of interacting scalar field model from the perspective of the dynamical systems theory

Understand

In this work, considering the background dynamics of flat Friedmann-Lemaitre-Robertson-Walker(FLRW) model of the universe, we investigate a scalar field model as dark energy candidate which interacting with the pressure-less dust as dark matter from dynamical systems perspective.

• From phenomenological vantage point two interaction terms are chosen: one depends on Hubble parameter $H$ and other is local, independent of Hubble parameter.
• In interaction model 1, the scalar field potential as well as the coupling are considered to be in the form of inverse square and accordingly a two-dimensional autonomous system is obtained.
• On the other hand, Interaction model 2 comprises with the potential as well as coupling of scalar field which are considered in form of exponential function of scalar field ($\phi$) and as a result of which a four-dimensional autonomous system is achieved.