EXACT STRING BACKGROUNDS FROM WZW MODELS BASED ON NON-SEMISIMPLE GROUPS

Abstract

We formulate WZW models based on a centrally extended version of the Euclidean group in d dimensions. We obtain string backgrounds corresponding to conformal σ models in D=d2 space-time dimensions with exact central charge c=d2 and d(d−1)/2 null Killing vectors. By identifying the corresponding conformal field theory we show that the one-loop results coincide with the exact ones up to a shifting of a parameter.