Nonlinear potential theory and Ricci-pinched 3-manifolds

In this paper, we focus on Hamilton’s pinching conjecture formulated in Hamilton’s paper “Three-manifolds with positive Ricci curvature”. Let $(M,g)$ be a complete, connected, noncompact Riemannian $3$-manifold satisfying the Ricci-pinching condition. Then, it is flat. Here, we give an alternative proof, based on nonlinear potential theory, under the extra hypothesis of superquadratic volume growth.