HARMONIC TWO-SPHERES IN THE SYMPLECTIC GROUP Sp(n)

Abstract

We shall exploit the Grassmannian theoretic point of view introduced by Segal in order to study harmonic maps from a two-sphere into the symplectic group Sp(n). By using this methodology, we shall be able to deduce an "uniton factorization" of such maps and an alternative characterization of harmonic two-spheres in the quaternionic projective space ℍP n .