Lehners, Jean-Luc String Cosmology, AEI-Golm, MPI for Gravitational Physics, Max Planck Society;
1705.00192.pdf (Preprint), 516KB
Feldbrugge, J., Lehners, J.-L., & Turok, N. (2017). No smooth beginning for spacetime. Physical Review Letters, 119: 171301. doi:10.1103/PhysRevLett.119.171301.