Cosmological Chaplygin gas as modified gravity

Abstract

In the scramble for the understanding of the nature of dark matter and dark energy, it has recently been suggested that the change of behavior of the missing energy density might be regulated by the change in the equation of state of the background fluid. The Chaplygin Gas (CG) model in cosmology is one of the most profound candidates for this suggestion. This work aims to bring to light a geometric interpretation of the model by re-writing the difierent toy models in terms of exact f(R) gravity solutions that are generally quadratic in the Ricci scalar with appropriate ΛCDM limiting solutions.