Abstract:
The dualisation and the first-order formulation of the D = 7 abelian Yang-Mills supergravity which is the low energy effective limit of the D = 7 fully Higssed heterotic string is discussed. The non-linear coset formulation of the scalars is enlarged to include the entire bosonic sector by introducing dual fields and by constructing the Lie superalgebra which generates the dualized coset element.