2005/05/31 by Robert Oeckl · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Nonlinear Waves and Solitons #Quantum Mechanics and Non-Hermitian Physics #hep-th #quant-ph
paper · pdf · doi:10.1016/j.physletb.2005.06.078
published as Phys.Lett. B622 (2005) 172-177 · 4 pages, 2 figures, LaTeX + revtex4 + eepic
arxiv created 2005/05/31 · openalex publication_date 2005/07/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the possibility of defining states on timelike hypersurfaces in quantum field theory. To this end we consider hyperplanes in the real massive Klein-Gordon theory using the Schroedinger representation. We find a well defined vacuum wave functional, existing on any hyperplane, with the remarkable property that it changes smoothly even under Euclidean rotation through the light-cone. Moreover, particles on timelike hyperplanes exist and occur in two variants, incoming and outgoing, distinguished by the sign of the energy. Multi-particle wave functionals take a form similar to those on spacelike hypersurfaces. The role of unitarity and the inner product is discussed.