Simplify[(3*((((1/2)*(c^2))/
                        G) - (1 - (((c - 
                                        c*(((c/
                                        CBRWavelength)/((c^3/(16*PI*
                                        G))/(4/3*PI*((((3/(8*
                                        rho*PI*G))^(1/2))*c)^3)*
                                        rho)))^2))/(1 + (((c/CBRWavelength)/((c^3/(16*PI*G))/(4/3*
                                        PI*((((3/(8*rho*PI*
                                        G))^(1/2))*c)^3)*
                                        rho)))^2)))^2)/
                              c^2)^(1/2)*(((1/2)*(c^2))/
                          G))/(4*PI*rho))^(1/2) - 
        G*((2*(4/3*
                      PI*((((3/(8*rho*PI*G))^(1/2))*
                              c)^3)*rho))/(c^2))]