  We compute effective equations of the quantum FRW flat universe in the
radiation dominated era at $\hbar$ order, described in terms of Ashtekar
variables employing a new method for the geometrical formulation of quantum
mechanics. Additional terms of quantum nature correct the classical equations
of motion. As a consequence, the initial singularity of the classical model is
removed and a Big Bouncing scenario takes its place. We also obtain an
expression for the effective action of the model in terms of higher curvature
invariants, leading us to corrected Einstein equations for more general
contexts.
