English

Urysohn width of hypersurfaces and positive macroscopic scalar curvature

Differential Geometry 2025-04-10 v1

Abstract

We prove that if a complete Riemannian nn-manifold with non-trivial codimension 1 homology with Z2\mathbb{Z}_2-coefficients or Z\mathbb{Z}-coefficients has positive macroscopic scalar curvature large enough, then it contains a non-nullhomologous hypersurface of small Urysohn (n2)(n-2)-width. This constitutes a macroscopic analogue of a theorem by Bray--Brendle--Neves on the area of non-contractible 2-spheres in a closed Riemannian 3-manifold with positive scalar curvature. Our proof is based on an adaptation of Guth's macroscopic version of the Schoen-Yau descent argument.

Keywords

Cite

@article{arxiv.2504.06737,
  title  = {Urysohn width of hypersurfaces and positive macroscopic scalar curvature},
  author = {Teo Gil Moreno de Mora Sardà},
  journal= {arXiv preprint arXiv:2504.06737},
  year   = {2025}
}

Comments

12 pages, 3 figures