Astronomy and Astrophysics – Astrophysics – General Relativity and Quantum Cosmology
Scientific paper
1995-05-19
Phys.Rev.D52:5687-5697,1995
Astronomy and Astrophysics
Astrophysics
General Relativity and Quantum Cosmology
30 pages, REVTeX; 3 postscript figures in a separate uuencoded file
Scientific paper
10.1103/PhysRevD.52.5687
We examine quantum field theory in spacetimes that are time nonorientable but have no other causal pathology. These are Lorentzian universes-from-nothing, spacetimes with a single spacelike boundary that nevertheless have a smooth Lorentzian metric. Classically, such spacetimes are locally indistinguishable from their globally hyperbolic covering spaces. However, the construction of a quantum field theory (QFT) is more problematic. One can define a family of local algebras on an atlas of globally hyperbolic subspacetimes. But one cannot extend a generic positive linear function from a single algebra to the collection of all local algebras without violating positivity, while satisfying the physically appropriate overlap conditions. This difficulty can be overcome by restricting the size of neighborhoods so that the union of any pair is time- orientable. The structure of local algebras and states is then locally indistinguishable from that of QFT on a globally hyperbolic spacetime. But this size restriction on neighborhoods makes the structure unsatisfactory as a global field theory. The theory allows less information than QFT in a globally hyperbolic spacetime, because correlations between field operators at a pair of points are defined only if a curve joining the points lies in a single neigh- borhood. Moreover, to extend a local state to a collection of states, we use an antipodally symmetric state on the covering space, a state that would not yield a sensible state on the spacetime if all correlations could be measured.
Friedman John L.
Higuchi Atsushi
No associations
LandOfFree
Quantum field theory in Lorentzian universes-from-nothing does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Quantum field theory in Lorentzian universes-from-nothing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantum field theory in Lorentzian universes-from-nothing will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-84604