237 research outputs found
Hyperplane arrangements and K-theory
We study the Z/2-equivariant K-theory of the complement of the
complexification of a real hyperplane arrangement. We compute the rational K
and KO rings, and give two different combinatorial descriptions of the subring
of the integral KO ring generated by line bundles.Comment: 11 pages, no figures; final version, to appear in Topology and its
Application
Abelianization for hyperkahler quotients
We study an integration theory in circle equivariant cohomology in order to
prove a theorem relating the cohomology ring of a hyperkahler quotient to the
cohomology ring of the quotient by a maximal abelian subgroup, analogous to a
theorem of Martin for symplectic quotients. We discuss applications of this
theorem to quiver varieties, and compute as an example the ordinary and
equivariant cohomology rings of a hyperpolygon space.Comment: 18 pages, 1 figur
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