English

Hamiltonian $S^1$-actions on complete intersections

Symplectic Geometry 2022-03-14 v4

Abstract

We study the problem of determining which diffeomorphism classes of K\"{a}hler manifolds admit a Hamiltonian circle action. Our main result is the following: Let MM be a closed symplectic manifold, diffeomorphic to a complete intersection with complex dimension 4k4k, having a Hamiltonian circle action such that each component of the fixed point set is an isolated fixed point or has dimension 2mod42 \mod 4. Then MM is diffeomorphic to CP4k\mathbb{CP}^{4k}, a quadric QCP4k+1Q \subset \mathbb{CP}^{4k+1} or an intersection of two quadrics Q1Q2CP4k+2Q_1 \cap Q_2 \subset \mathbb{CP}^{4k+2}.

Keywords

Cite

@article{arxiv.2008.00839,
  title  = {Hamiltonian $S^1$-actions on complete intersections},
  author = {Nicholas Lindsay},
  journal= {arXiv preprint arXiv:2008.00839},
  year   = {2022}
}

Comments

Accepted version, to appear in Bulletin of the London Mathematical Society. 7 Pages

R2 v1 2026-06-23T17:36:02.401Z