CLOSED FRIEDMANN MODEL IN A MODIFIED GRAVITATIONAL THEORY

Abstract

We consider a closed Friedmann model in modified theory of gravity (including the Riemann tensor). The dependence of the scale factor on time for a hot ultrarelativistic case . 3 p ⎟ ⎠⎞ ⎜⎝⎛ ε = In this case the exponent of the Riemann tensor chosen as . 2 α = 1 If we set the parameter A = 6 , then, we obtain a solution in which there is no physical singularity. A similar solution was obtained at A = 3.