Chaplygin-gas Solutions of f(R) Gravity
  We explore exact f(R) gravity solutions that mimic Chaplygin-gas inspired LCDM cosmology. Starting with the original and modified Chaplygin gas equations of state, we reconstruct the forms of f(R) Lagrangians. The resulting solutions are generally quadratic in the Ricci scalar, but have appropriate LCDM solutions in limiting cases. These solutions, given appropriate initial conditions, can be potential candidates for scalar field-driven early universe expansion (inflation) and dark energy-driven late-time cosmic acceleration. 
Maye Elmardi, Amare Abebe and Abiy Tekola
gr-qc astro-ph.CO