Dark energy and dust matter phases from an exact $f(R)$-cosmology model
  We show that dust matter-dark energy combined phases can be achieved by the exact solution derived from a power law $f(R)$ cosmological model. This example answers the query by which a dust-dominated decelerated phase, before dark-energy accelerated phase, is needed in order to form large scale structures. 
S.Capozziello, P. Martin-Moruno, C. Rubano