A “general boundary” formulation for quantum mechanics and quantum gravity
Abstract
I propose to formalize quantum theories as topological quantum field theories in a generalized sense, associating state spaces with boundaries of arbitrary (and possibly finite) regions of spacetime. I further propose to obtain such "general boundary" quantum theories through a generalized path integral quantization. I show how both, nonrelativistic quantum mechanics and quantum field theory can be given a "general boundary" formulation. Surprisingly, even in the nonrelativistic case, features normally associated with quantum field theory emerge from consistency conditions. This includes states with arbitrary particle number and pair creation. I also note how threedimensional quantum gravity is an example for a realization of both proposals and suggest to apply them to fourdimensional quantum gravity.
 Publication:

Physics Letters B
 Pub Date:
 November 2003
 DOI:
 10.1016/j.physletb.2003.08.043
 arXiv:
 arXiv:hepth/0306025
 Bibcode:
 2003PhLB..575..318O
 Keywords:

 High Energy Physics  Theory;
 General Relativity and Quantum Cosmology;
 Quantum Physics
 EPrint:
 5 pages, 2 figures, LaTeX + revtex4 + eps