Decay of the free-theory vacuum of scalar field theory in de Sitter spacetime in the interaction picture

摘要: A free-theory vacuum state of an interacting field theory, e.g. quantum gravity, is unstable at tree level in general due to spontaneous emission Fock-space particles any spacetime with no global timelike Killing vectors, such as de Sitter spacetime, the interaction picture. As example, rate calculated 4 theory spacetime. It possible that this apparent does not correspond physical processes because states are evolved by true Hamiltonian Nevertheless, constant picture indicates in- and out-vacuum orthogonal each other emphasized Polyakov in-out perturbation which presupposes some overlap between these two states, inadequate. Other implications instability kind also discussed.