2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/70457The real homology of a compact, n-dimensional Riemannian manifold M is naturally endowed with the stable norm. The stable norm of a homology class is the minimal Riemannian volume of its representatives. If M is orientable the stable norm on H_{n-1}(M,R) is a homogenized version of the Riemannian (n-1)-volume. We study the differentiability properties of the stable norm at points alpha in H_{n-1}(M,R). They depend on the position of alpha with respect to the integer lattice H_{n-1}(M,Z) in H_{n-1}(M,R). In particular, we show that the stable norm is differentiable at alpha if alpha is totally irrational.28 pages LaTeX. Submitted to American Journal of Mathematics; Reference added. Minor inaccuracy corrected; Revised version for publication after referee report. Proof of Propositon 2.4 added. Some inaccuracies corrected and some unclear formulations changedDifferential GeometryAnalysis of PDEs49Q20 (Primary) 35B27, 53C38 (Secondary)text