G/G--Topological Field Theories by Cosetting Gₖ

الأصل · EN

G/G topological field theories based on Gₖ WZW models are constructed and studied. These coset models are formulated as Complex BRST cohomology in Gᶜₖ, the complexified level k current algebra. The finite physical spectrum corresponds to the conformal blocks of Gₖ.The amplitudes for G/G theories are argued to be given in terms of the Gₖ fusion rules. The Gₖ/Gₖ character is the Kac-Weyl numerator of Gₖ and is interpreted as an index. The Complex BRST cohomology is found to contain states of arbitrary ghost number. Intriguing similarities of G/G to c≤ 1 matter systems coupled to two dimensional gravity are pointed out.