Lehners, Jean-Luc String Cosmology, AEI-Golm, MPI for Gravitational Physics, Max Planck Society;
1703.02076.pdf (Preprint), 4MB
Feldbrugge, J., Lehners, J.-L., & Turok, N. (2017). Lorentzian Quantum Cosmology. Physical Review D, 95: 103508. doi:10.1103/PhysRevD.95.103508.