Abstract
We study Hamiltonian R-actions on symplectic orbifolds [M/S], where R and S are tori. We prove an injectivity theorem and generalize Tolman and Weitsman’s proof of the GKM theorem [TW] in this setting. The main example is the symplectic reduction X//S of a Hamiltonian T-manifold X by a subtorus S ⊂ T. This includes the class of symplectic toric orbifolds. We define the equivariant Chen–Ruan cohomology ring and use the above results to establish a combinatorial method of computing this equivariant Chen–Ruan cohomology in terms of orbifold fixed point data.
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Holm, T.S., Matsumura, T. Equivariant cohomology for Hamiltonian torus actions on symplectic orbifolds. Transformation Groups 17, 717–746 (2012). https://doi.org/10.1007/s00031-012-9192-7
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DOI: https://doi.org/10.1007/s00031-012-9192-7