Lehners, Jean-Luc String Cosmology, AEI-Golm, MPI for Gravitational Physics, Max Planck Society;
1309.2281.pdf (Preprint), 9MB
PhysRevD.89_063516.pdf (Any fulltext), 996KB
Battarra, L., & Lehners, J.-L. (2014). On the Quantum-To-Classical Transition for Ekpyrotic Perturbations. Physical Review D, 89: 063516. doi:10.1103/PhysRevD.89.063516.