English

Cohomology of GKM-sheaves

Algebraic Topology 2018-06-08 v2

Abstract

Let TT be a compact torus and XX be a a finite TT-CW complex (e.g. a compact TT-manifold). In earlier work, the second author introduced a functor which assigns to XX a so called GKM-sheaf FX\mathcal{F}_X whose ring of global sections H0(FX)H^0(\mathcal{F}_X) is isomorphic to the equivariant cohomology HT(X)H^*_T(X) whenever XX is equivariantly formal (meaning that HT(X)H^*_T(X) is a free module over H(BT))H^*(BT)). In the current paper we prove more generally that H0(FX)HT(X)H^0(\mathcal{F}_X) \cong H^*_T(X) if and only if HT(X)H_T^*(X) is reflexive, and find a geometric interpretation of the higher cohomology Hn(FX)H^n(\mathcal{F}_X) for n1n \geq 1.

Keywords

Cite

@article{arxiv.1806.01761,
  title  = {Cohomology of GKM-sheaves},
  author = {Ibrahem Al-Jabea and Thomas John Baird},
  journal= {arXiv preprint arXiv:1806.01761},
  year   = {2018}
}

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13 pages