On the structure of the vacuum state in general boundary quantum field theory
arXiv:0903.2476
Abstract
We quantize a real massive Klein-Gordon field in curved spacetimes within the general boundary formulation. The vacuum wave function is given by a Gaussian in the Schrödinger representation and we study the general structure of the operator appearing in the Gaussian. We show that it obeys a Riccati equation and we provide the general solution.
10 pages, LaTeX + revtex4