English

Examples of symplectic non-leaves

Symplectic Geometry 2025-02-04 v2 Geometric Topology

Abstract

This paper deals with the following question: which manifolds can be realized as leaves of codimension-1 symplectic foliations on closed manifolds? We first observe that leaves of symplectic foliations are necessarily strongly geometrically bounded. We show that a symplectic structure which admits an exhaustion by compacts with (convex) contact boundary can be deformed to a strongly geometrically bounded one. We then give examples of smooth manifolds which admit a strongly geometrically bounded symplectic form and can be realized as a smooth leaf, but not as a symplectic leaf for any choice of symplectic form on them. Lastly, we show that the (complex) blowup of 2n-dimensional Euclidean space at infinitely many points, both admits strongly geometrically bounded symplectic forms for which it can and cannot be realized as a symplectic leaf.

Keywords

Cite

@article{arxiv.2106.02618,
  title  = {Examples of symplectic non-leaves},
  author = {Fabio Gironella and Lauran Toussaint},
  journal= {arXiv preprint arXiv:2106.02618},
  year   = {2025}
}

Comments

v2: Acknowledgements updated. v1: 17 pages

R2 v1 2026-06-24T02:50:58.608Z