  In this paper the dynamics of a fractional order system modelling the
interaction between dark matter and dark energy is analytically and numerically
studied. It is shown for the first time that systems modelling the interaction
between dark matter and dark energy, chaotic hidden attractors can be present.
The chaotic attractor co-exists with two asymptotically stable equilibria.
Equilibria of the linearized system exhibit a center-like behavior. The
numerical integration is done by means of the Adams-Bashforth-Moulton scheme
and the finite Lyapunov exponents are numerically determined with a dedicated
Matlab code. The 3D representation of the chaotic hidden attractor reveals the
fact it is not connected with the equilibria, being `hidden` somewhere in the
considered phase space.
