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Type II NS Five‐Branes: Non Critical Strings and their Topological Sectors
Author(s) -
Kounnas Costas
Publication year - 2001
Publication title -
fortschritte der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.469
H-Index - 71
eISSN - 1521-3978
pISSN - 0015-8208
DOI - 10.1002/1521-3978(200105)49:4/6<599::aid-prop599>3.0.co;2-f
Subject(s) - worldsheet , physics , brane cosmology , dilaton , brane , conformal field theory , invariant (physics) , abelian group , theoretical physics , conformal map , mathematical physics , string theory , string field theory , geometry , pure mathematics , mathematics
The near‐horizon geometry of parallel NS5‐branes is described by an exact superconformal 2d field theory based on 10 ≡ W k 4 × ℳ 6 , with ℳ 6 a flat 5 + 1 space time and W k 4 ≡ U (1) ⊗ SU (2) k , a four dimensional background with non‐trivial dilaton. The ten‐dimensional “BULK” spectrum of excitations of 10 can be derived combining unitary representations of the = 4 superconformal theory of W k 4 and ℳ 6 in a modular‐invariant way. All Bulk states are massive and belong to the long representations of the N 6 = 2 space‐time supersymmetry. The NS5‐brane states, propagating on ℳ 6 , belong to the short representations of N 6 = 2. Both the bulk and the brane spectrum is derived using the powerful worldsheet technics of the = 4 superconformal theories. We claim that both bulk and brane states are necessary to well define the theory. The non abelian U ( n ) or SO (2 n ) structure of the 5‐brane fields follows from the fusion coefficients appearing in the correlation functions involving SU (2) k conformal fields.