Attractor Solutions in Interacting Dark Energy Models

Abstract

We investigate a cosmological model in which dark energy, represented by a quintessential scalar field, is coupled to a dark-matter perfect fluid in the spatially flat Friedmann-Robertson-Walker Universe. This allows an energy exchange in the dark sector which could happen both at early times before recombination era or at late times. We use the coupling function $Q=\gamma {\rho }_{dm}\dot{\phi }$ which is induced by conformal transforming scalar-tensor and $f(R)$ gravity theories to Einstein frame. It is argued that there is a connection between this coupling function and $Q\propto {\rho }_{dm}H$. A dynamical analysis is used to show that there are early- and late-time attracting solutions for which the system evolves for a wide range of initial conditions. These attractors generalize the scaling solutions which have been already found in the non-interacting case.

9 pages, 2 figures

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Cited by in corpus (4)

• Dynamical systems of modified Gauss-Bonnet gravity: cosmological implications
• Constructing Viable Interacting Dark Matter and Dark Energy Models: A Dynamical Systems Approach
• Some Classes of Interacting Two-Fluid Model of the Expanding Universe
• $f(R,\mathcal{G})$-cosmological dynamics in the FLRW background