Gravitational four-fermion interaction in the early Universe

If torsion exists, it generates gravitational four-fermion interaction (GFFI), essential on the Planck scale. We analyze the influence of this interaction on the Friedmann–Lemaitre–Robertson–Walker cosmology. An explicit analytic solution is derived for the problem where both the energy–momentum tensor generated by GFFI and the common ultrarelativistic energy–momentum tensor are included. We demonstrate that gravitational four-fermion interaction does not result in a Big Bounce.