Propagation of a string across the cosmological singularity

Our results concern the transition of a quantum string through the singularity of the compactified Milne (CM) space. We restrict our analysis to the string winding around the compact dimension (CD) of spacetime. The CD undergoes contraction to a point followed by re-expansion. We demonstrate that both the classical and quantum dynamics of the considered string are well defined. Most of the presently available calculations strongly suggest that the singularity of a time-dependent orbifold is useless as a model of the cosmological singularity. We believe that our results bring, to some extent, this claim into question.