It is offered that F(R)−modified gravities can be considered as
nonperturbative quantum effects arising from Einstein gravity. It is assumed
that nonperturbative quantum effects gives rise to the fact that the connection
becomes incompatible with the metric, the metric factors and the square of the
connection in Einstein - Hilbert Lagrangian have nonperturbative additions. In
the simplest approximation both additions can be considered as functions of one
scalar field. The scalar field can be excluded from the Lagrangian obtaining
F(R)−gravity. The essence of quantum correction to the affine connection as a
torsion is discussed.Comment: discussion on quantum corrections is adde