English

Lagrangian Surplusection Phenomena

Symplectic Geometry 2024-12-09 v3 Differential Geometry Geometric Topology

Abstract

Suppose you have a family of Lagrangian submanifolds LtL_t and an auxiliary Lagrangian KK. Suppose that KK intersects some of the LtL_t more than the minimal number of times. Can you eliminate surplus intersection (surplusection) with all fibres by performing a Hamiltonian isotopy of KK? Or will any Lagrangian isotopic to KK surplusect some of the fibres? We argue that in several important situations, surplusection cannot be eliminated, and that a better understanding of surplusection phenomena (better bounds and a clearer understanding of how the surplusection is distributed in the family) would help to tackle some outstanding problems in different areas, including Oh's conjecture on the volume-minimising property of the Clifford torus and the concurrent normals conjecture in convex geometry. We pose many open questions.

Keywords

Cite

@article{arxiv.2408.14883,
  title  = {Lagrangian Surplusection Phenomena},
  author = {Georgios Dimitroglou Rizell and Jonathan David Evans},
  journal= {arXiv preprint arXiv:2408.14883},
  year   = {2024}
}
R2 v1 2026-06-28T18:25:02.668Z