2026/03/31 by Brayan Ferreira, Marcelo Miranda, Alejandro Vicente · 1 voice
Mathematics · #math.SG #math.DG
arxiv published 2026/03/31 · arxiv updated 2026/06/18
We study contact 3-manifolds Y with a special global frame inspired by Cartan's structure equations. This frame is dual to a generalized Finsler structure defined by Bryant. We present some examples and rigidity results on the class of manifolds whose frame satisfies certain natural conditions on a scalar function K\colon Y→ ℝ, related to the frame. This function realizes the curvature when Y is the unit tangent bundle with respect to a metric on a surface. As applications, we obtain sharp estimates for the action of a Reeb orbit in terms of this scalar function, under the assumption that the frame satisfies specific conditions. In particular, we recover a classical upper bound on the systole of positively curved metrics on S2 due to Toponogov.