English

The sigma orientation for analytic circle-equivariant elliptic cohomology

Algebraic Topology 2014-11-11 v4

Abstract

We construct a canonical Thom isomorphism in Grojnowski's equivariant elliptic cohomology, for virtual T-oriented T-equivariant spin bundles with vanishing Borel-equivariant second Chern class, which is natural under pull-back of vector bundles and exponential under Whitney sum. It extends in the complex-analytic case the non-equivariant sigma orientation of Hopkins, Strickland, and the author. The construction relates the sigma orientation to the representation theory of loop groups and Looijenga's weighted projective space, and sheds light even on the non-equivariant case. Rigidity theorems of Witten-Bott-Taubes including generalizations by Kefeng Liu follow.

Keywords

Cite

@article{arxiv.math/0201092,
  title  = {The sigma orientation for analytic circle-equivariant elliptic cohomology},
  author = {Matthew Ando},
  journal= {arXiv preprint arXiv:math/0201092},
  year   = {2014}
}

Comments

Published in Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol7/paper3.abs.html

R2 v1 2026-07-22T16:42:38.301Z