Generalizations of normal ordering and applications to quantization in classical backgrounds
Abstract
A nonlocal method of extracting the positive (or the negative) frequency part of a field, based on knowledge of a 2point function, leads to certain natural generalizations of the normal ordering of quantum fields in classical gravitational and electromagnetic backgrounds and illuminates the origin of the recently discovered nonlocalities related to a local description of particles. A local description of particle creation by gravitational backgrounds is given, with emphasis on the case of blackhole evaporation. The formalism reveals a previously hidden relation between various definitions of the particle current and those of the energy momentum tensor. The implications to particle creation by classical backgrounds, as well as to the relation between vacuum energy, dark matter, and cosmological constant, are discussed.
 Publication:

General Relativity and Gravitation
 Pub Date:
 February 2005
 DOI:
 10.1007/s1071400500204
 arXiv:
 arXiv:hepth/0205022
 Bibcode:
 2005GReGr..37..297N
 Keywords:

 Current of particle density;
 Classical background;
 Particle creation;
 High Energy Physics  Theory;
 General Relativity and Quantum Cosmology
 EPrint:
 17 pages, revised, title shortened, to appear in Gen. Rel. Grav