English

A^1-Euler classes: six functors formalisms, dualities, integrality and linear subspaces of complete intersections

K-Theory and Homology 2021-05-20 v2 Algebraic Geometry Algebraic Topology

Abstract

We equate various Euler classes of algebraic vector bundles, including those of [BM, KW, DJK], and one suggested by M.J. Hopkins, A. Raksit, and J.-P. Serre. We establish integrality results for this Euler class, and give formulas for local indices at isolated zeros, both in terms of 6-functor formalism of coherent sheaves and as an explicit recipe in commutative algebra of Scheja and Storch. As an application, we compute the Euler classes associated to arithmetic counts of d-planes on complete intersections in P^n in terms of topological Euler numbers over R and C.

Keywords

Cite

@article{arxiv.2002.01848,
  title  = {A^1-Euler classes: six functors formalisms, dualities, integrality and linear subspaces of complete intersections},
  author = {Tom Bachmann and Kirsten Wickelgren},
  journal= {arXiv preprint arXiv:2002.01848},
  year   = {2021}
}

Comments

version accepted for publication in Jussieu

R2 v1 2026-06-23T13:32:03.862Z