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2009 (English)In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 80, no 8, article id 086003Article in journal (Refereed) Published
Abstract [en]
We prove a no-ghost theorem for a bosonic string propagating in Nappi-Witten spacetime. This is achieved in two steps. We first demonstrate unitarity for a class of NW/U(1) modules: the norm of any state which is primary with respect to a chosen timelike U(1) is non-negative. We then show that physical states - states satisfying the Virasoro constraints - in a class of modules of an affinisation of the Nappi-Witten algebra are contained in the NW/U(1) modules. Similar to the case of strings on AdS3, in order to saturate the spectrum obtained in light-cone quantization we are led to include modules with energy not bounded from below, which are related to modules with energy bounded from below by spectral flow automorphisms.
Place, publisher, year, edition, pages
American Physical Society, 2009
National Category
Subatomic Physics
Identifiers
urn:nbn:se:oru:diva-57705 (URN)10.1103/PhysRevD.80.086003 (DOI)000271353700126 ()2-s2.0-70449728413 (Scopus ID)
Funder
Swedish Research Council, 348-2008-6049
Note
Funding Agencies:
NSFC 10535010 10775068
973 National Major State Basic Research and Development of China 2007CB815004
National Science Foundation of China 0204131361
Nanjing University
Chinese Government 020422420100
2014-11-252017-05-172017-10-18Bibliographically approved