String quantization: Fock vs. LQG Representations

Thumbnail Image

Date

Authors

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

Description

We set up a unified framework to compare the quantization of the bosonic string in two approaches: One proposed by Thiemann, based on methods of loop quantum gravity, and the other using the usual Fock space quantization. Both yield a diffeomorphism invariant quantum theory. We discuss why there is no central charge in Thiemann's approach but a discontinuity characteristic for the loop approach to diffeomorphism invariant theories. Then we show the (un)physical consequences of this discontinuity in the example of the harmonic oscillators such as an unbounded energy spectrum. On the other hand, in the continuous Fock representation, the unitary operators for the diffeomorphisms have to be constructed using the method of Gupta and Bleuler representing the diffeomorphism group up to a phase given by the usual central charge.
19 pages

Keywords

High Energy Physics - Theory, General Relativity and Quantum Cosmology

Citation

URI

http://salesiana.dossiersoluciones.com/handle/123456789/52774

Consulte el texto completo en el siguiente enlace:

https://arxiv.org/abs/hep-th/0409182
 http://arxiv.org/abs/hep-th/0409182

Collections

arXiv