Further properties of classical solutions in grassmannian sigma models

We calculate the action and the topological charge of classical solutions in two-dimensional euclidean grassmannian sigma models (for both generic and special solutions). We show that all the above non-instanton or non-anti-instanton solutions are unstable. We also find solutions of the Dirac equation describing fermions in the background of these grassmannian fields, and we exhibit relations between these fermionic solutions and those of the associated Hilbert-Riemann problem. (orig.)