English

Spectrum of equivariant cohomology as a fixed point scheme

Algebraic Geometry 2026-05-27 v5 Algebraic Topology

Abstract

An action of a complex reductive group G\mathrm G on a smooth projective variety XX is regular when all regular unipotent elements in G\mathrm G act with finitely many fixed points. Then the complex G\mathrm G-equivariant cohomology ring of XX is isomorphic to the coordinate ring of a certain regular fixed point scheme. Examples include partial flag varieties, smooth Schubert varieties and Bott-Samelson varieties. We also show that a more general version of the fixed point scheme allows a generalisation to GKM spaces, such as toric varieties.

Keywords

Cite

@article{arxiv.2212.11836,
  title  = {Spectrum of equivariant cohomology as a fixed point scheme},
  author = {Tamás Hausel and Kamil Rychlewicz},
  journal= {arXiv preprint arXiv:2212.11836},
  year   = {2026}
}

Comments

57 pages, 7 figures. Comments are welcome