Big crunch avoidance in k=1 semiclassical loop quantum cosmology -: art. no. 104008

It is well known that a closed universe with a minimally coupled massive scalar field always collapses to a singularity unless the initial conditions are extremely fine-tuned. We show that the corrections to the equations of motion for the massive scalar field, given by loop quantum gravity in the high curvature regime, always lead to a bounce independently of the initial conditions. In contrast with the previous works in loop quantum cosmology, we note that the singularity can be avoided even at the semiclassical level of effective dynamical equations with nonperturbative quantum gravity modifications, without using a discrete quantum evolution.