Antisymmetric tensor coupling and conformal invariance in [sigma] models corresponding to gauged WZNW theories

Journal Article · Tue Mar 15 04:00:00 EST 1994 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.49.2933· OSTI ID:5173235

Sfetsos, K ^[1]; Tseytlin, A A ^[2]

---

1. Institute for Theoretical Physics, Utrecht University, Princetonplein 5, TA 3508 (Netherlands)
2. Theory Division, CERN, CH-1211 Geneva 23 (Switzerland) Blackett Laboratory, Imperial College, London SW72BZ (United Kingdom)

String backgrounds associated with gauged [ital G]/[ital H] WZNW models generically depend on [alpha] [prime] or 1/[ital k]. The exact expressions for the corresponding metric [ital G][sub [mu][nu]], antisymmetric tensor [ital B][sub [mu][nu]], and dilaton [phi] can be obtained by eliminating the two-dimensional gauge field from the local part of the effective action of the gauged WZNW model. We show that there exists a manifestly gauge-invariant prescription for the derivation of the antisymmetric tensor coupling and discuss some subtleties involved. When the subgroup [ital H] is one dimensional and [ital G] is simple the antisymmetric tensor is given by the semiclassical ([alpha] [prime]-independent) expression. We consider in detail the simplest nontrivial example with [ital B][sub [mu][nu]][ne]0, the [ital D]=3 [sigma] model corresponding to the [SL(2,[ital openR])[times][ital openR]]/[ital openR] gauged WZNW theory ( charged black string''), and show that the exact expressions for [ital G][sub [mu][nu]], [ital B][sub [mu][nu]], and [phi] solve the Weyl invariance conditions in the two-loop approximation. A similar conclusion is reached for the closely related SL(2,[ital openR])/[ital openR] chiral gauged WZNW model. We find that there exists a scheme in which the semiclassical background is also a solution of the two-loop conformal invariance equations (but the tachyon equation takes a noncanonical form). We discuss in detail the role of field redefinitions (scheme dependence) in establishing a correspondence between the [sigma] model and conformal field theory results.

• OSTI ID: 5173235
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 49:6; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

662110* -- General Theory of Particles & Fields-- Theory of Fields & Strings-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BOSON-EXCHANGE MODELS
COMPOSITE MODELS
CONFORMAL INVARIANCE
COUPLING
ELEMENTARY PARTICLES
EXTENDED PARTICLE MODEL
INVARIANCE PRINCIPLES
MATHEMATICAL MODELS
PARTICLE MODELS
PERIPHERAL MODELS
POSTULATED PARTICLES
QUARK MODEL
SIGMA MODEL
STRING MODELS
TACHYONS
TENSORS
UNIFIED GAUGE MODELS