2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/199471We study the modified theory of gravity in Friedmann Robertson Walker universe composed of several perfect fluids. We consider the power law inflation and determine the equation of state parameters in terms of the parameters of modified gravity's Lagrangian in the early universe. We also discuss briefly the gravitational baryogenesis in this model.9 pages, accepted for publication in Physical Review DGeneral Relativity and Quantum CosmologyAstrophysicsHigh Energy Physics - Theorytext