On the twisted G/H topological models

The twisted G/H models are constructed as twisted supersymmetric gauged WZW models. We analyze the case of G=SU(N), H=SU(N1)x..xSU(Nn)xU(1)r with rank(G)=rank(H), and discuss possible generalizations. We introduce a non-abelian bosonization of the (1, 0) ghost system in the adjoint of H and in G/H. By computing chiral anomalies in the latter picture we write the quantum action as a decoupled sum of 'matter', gauge and ghost sectors. The action is also derived in the unbosonized version. We invoke a free field parameterization and extract the space of physical states by computing the cohomology of Q, the sum of the BRST gauge-fixing charge and the twisted supersymmetry charge. For a given G we briefly discuss the relation between the various G/H models corresponding to different choices of H. The choice H=G corresponds to the topological G/G theory. (orig.)