Centralizers of Hamiltonian circle actions on rational ruled surfaces

Pranav Chakravarthy, Martin Pinsonnault

In this paper, we compute the homotopy type of the group of equivariant symplectomorphisms of $S^2\times S^2$ and $\mathbb{C}{P}^2\#\overline{\mathbb{C}{P}^2}$ under the presence of…