English

Periodic symplectic and Hamiltonian diffeomorphisms on irrational ruled surfaces

Symplectic Geometry 2025-10-08 v2 Geometric Topology

Abstract

We study the extension of homologically trivial symplectic or Hamiltonian cyclic actions to Hamiltonian circle actions on irrational ruled symplectic 44-manifolds. On one hand, we construct symplectic involutions on minimal irrational ruled 44-manifolds that cannot extend to a symplectic circle action even with a possibly different symplectic form. Higher dimensional examples are also constructed. On the other hand, for homologically trivial symplectic cyclic actions of any other order, we show that such an extension always exists. We also classify finite groups of symplecticmorphisms that acts trivially on the first homology group, and prove the non-extendability of the Klein 44-group action to the three dimensional rotation group action motivated by the classification of finite groups of symplectomorphisms.

Keywords

Cite

@article{arxiv.2411.18580,
  title  = {Periodic symplectic and Hamiltonian diffeomorphisms on irrational ruled surfaces},
  author = {Nicholas Lindsay and Weiyi Zhang},
  journal= {arXiv preprint arXiv:2411.18580},
  year   = {2025}
}

Comments

41 pages, 3 figures. Exposition improved and new results on finite subgroups of symplectomorphisms for irrational ruled 4-manifolds are added