English

Almgren's Three-Legged Starfish

Differential Geometry 2025-04-30 v1

Abstract

In this note we use classical tools from min-max and hyperbolic geometry to substantiate a folklore example in Almgren--Pitts min-max theory, the three-legged starfish metric on a 2-sphere, whose systolic length, Almgren--Pitts width, and Gromov--Guth width are attained by ``figure-eight'' geodesics. We also recover a hyperbolic geometry fact about ``figure-eight'' geodesics using min-max.

Cite

@article{arxiv.2504.20895,
  title  = {Almgren's Three-Legged Starfish},
  author = {Christos Mantoulidis and Jared Marx-Kuo},
  journal= {arXiv preprint arXiv:2504.20895},
  year   = {2025}
}

Comments

8 pages, 1 figure, comments welcome!

R2 v1 2026-06-28T23:15:35.820Z