Equivariant cohomological rigidity for four-dimensional Hamiltonian
$\mathbf{S^1}$-manifolds
Equivariant cohomological rigidity for four-dimensional Hamiltonian
$\mathbf{S^1}$-manifolds
For manifolds equipped with group actions, we have the following natural question: To what extent does the equivariant cohomology determine the equivariant diffeotype? We resolve this question for Hamiltonian circle actions on compact, connected symplectic four-manifolds. They are equivariantly diffeomorphic if and only if their equivariant cohomology rings are isomorphic …