Allen, Bruce Observational Relativity and Cosmology, AEI-Hannover, MPI for Gravitational Physics, Max Planck Society;
phd-32-85-ba.pdf (Verlagsversion), 3MB
Allen, B. (1985). Vacuum states in de Sitter space. Physical Review D, 32(12), 3136-3149. doi:10.1103/PhysRevD.32.3136.