Making use of the T-duality symmetry of superstring theory and of the double geometry from double field theory, we argue that cosmological singularities of a homogeneous and isotropic universe disappear. In fact, an apparent big bang singularity in Einstein gravity corresponds to a universe expanding to infinite size in the dual dimensions.
Brandenberger, R., Costa, R., Franzmann, G., & Weltman, A. (2018). Dual spacetime and nonsingular string cosmology. Physical Review D, 98(6), 063521.