A Tree Theorem for Inflation
arXiv:0805.3781 · doi:10.1103/PhysRevD.78.063534
Abstract
It is shown that the generating function for tree graphs in the "in-in" formalism may be calculated by solving the classical equations of motion subject to certain constraints. This theorem is illustrated by application to the evolution of a single inflaton field in a Robertson--Walker background.
Version accepted for publication in Phys. Rev. D. 22 pages. Some changes to references and clarification in Introduction