3 papers
math.SG2026
Symplectic torus actions with non-contractible orbits
Rei Henigman, Yael Karshon
We prove that a symplectic action on a closed connected -dimensional symplectic manifold is Hamiltonian if and only if its orbits are contractible. This generalizes a…
math.SG2026
Classification of symplectic non-Hamiltonian circle actions on 4-manifolds
Rei Henigman
We classify symplectic non-Hamiltonian circle actions on compact connected symplectic 4-manifolds, up to equivariant symplectomorphisms. Namely, we define a set of invariants, show…
math.SG2025
Maximal symplectic torus actions
Rei Henigman
There are several different notions of maximal torus actions on smooth manifolds, in various contexts: symplectic, Riemannian, complex. In the symplectic context, for the so-called…