Planckian pre big bang phase of the Universe

Abstract

The standard model of cosmology, although very successful, has problems with the very initial phase, such as the existence of a singularity when the density and curvature becomes infinite. In this work we propose a possible non-singular beginning of the Universe. From quantum considerations we set the earliest epoch to be the Planck epoch, which implies that the Universe did not begin with a singularity but with a finite minimal size of $10^{-3}~\mbox{cm}$. We suggest that the Universe initially began at the Planck length as a fluctuation having Planck energy expanding exponentially at constant Planck density, which then in turn accounts for the matter creation. All matter at the present epoch was created by the time the size of the Universe reached this minimal scale ($10^{-3}~\mbox{cm}$) starting from Planck length. We call this the Planck scale inflation. We also consider a time varying cosmological constant.