A duality-like transformation in WZNW models inspired by dual riemannian globally symmetric spaces

On the Exceptional Gauged WZW Theories

“…Moreover the duality transformation is implemented by an automorphism of the gauged subgroup [4,5,6,7]. When the gauged subgroup is not semisimple, and in particular when it is null, the target space of vector gauged WZW model reduces to a space with less dimensions [8,9,10,11]. In other words, it was shown that in the usual vector gauging of classical Lie group G WZW model, by its maximal null subgroup H, the effective action of the gauged model reduces to that of a Toda theory which the number of Toda fields is less than DimG-DimH.…”