Unitarity Condition on Quantum Fields in Semiclassical Gravity
arXiv:gr-qc/9511037 · doi:10.1016/0375-9601(95)00584-P
Abstract
The condition for the unitarity of a quantum field is investigated in semiclassical gravity from the Wheeler-DeWitt equation. It is found that the quantum field preserves unitarity asymptotically in the Lorentzian universe, but does not preserve unitarity completely in the Euclidean universe. In particular we obtain a very simple matter field equation in the basis of the generalized invariant of the matter field Hamiltonian whose asymptotic solution is found explicitly.
11 pages of Latex file, Revtex