Harmonic maps and fundamental groups of nonpositively curved Riemannian manifolds (Q1352485)

Let \(M\) be a complete Riemannian manifold of non-positive curvature and \(G\) a finitely generated subgroup of the fundamental group \(\pi_1(M)\), which contains a solvable subgroup of finite index. Using the theory of harmonic maps it is shown, that \(G\) can be realized by an immersed totally geodesic closed flag manifold or \(G\) is peripheral, i.e. for any compact \(K\subseteq M\) there is a component \(U\) of the complement such that \(G\) can be conjugated into the image of \(\pi_1(U)\).