The cohomology ring of symplectic cuts

Abstract

The ``symplectic cut'' construction [Lerman] produces two symplectic orbifolds $C_{-}$ and $C_{+}$ from a symplectic manifold $M$ with a Hamiltonian circle action. We compute the rational cohomology ring of $C_{+}$ in terms of those of $M$ and $C_{-}$.

8 pages, no pictures, LaTeX twice. Fixed some indices (that don't affect the result), and added a comment on alternate methods of calculation