English

The Hofer conjecture on embedding symplectic ellipsoids

Symplectic Geometry 2011-03-02 v4

Abstract

In this note we show that one open four dimensional ellipsoid embeds symplectically into another if and only the ECH capacities of the first are no larger than those of the second. This proves a conjecture due to Hofer. The argument uses the equivalence of the ellipsoidal embedding problem with a ball embedding problem that was recently established by McDuff. Its method is inspired by Hutchings' recent results on embedded contact homology (ECH) capacities but does not use them.

Keywords

Cite

@article{arxiv.1008.1885,
  title  = {The Hofer conjecture on embedding symplectic ellipsoids},
  author = {Dusa McDuff},
  journal= {arXiv preprint arXiv:1008.1885},
  year   = {2011}
}

Comments

v2 13 pages, 4 figures; significant revision; proof no longer uses results from embedded contact homology; v3 small corrections; v4 two new references, to be published in J. Differ. Geom

R2 v1 2026-06-21T15:59:26.876Z