English

Complex algebraic stacks and morphisms of intersection complexes

Algebraic Geometry 2025-04-08 v2

Abstract

We generalize a construction of Barthel-Brasselet-Fieseler-Gabber-Kaup in the setting of complex varieties to the setting of finite type, complex algebraic stacks. Given two such stacks X,Y\mathcal{X},\mathcal{Y} with affine stabilizers, and a morphism between them, we construct a morphism from the pullback of the intersection complex of Y\mathcal{Y} to the intersection complex of X\mathcal{X}. As an application, we show that the Borel-Moore fundamental class of a closed substack Z\mathcal{Z} in a Deligne-Mumford stack X\mathcal{X} lifts to a class in the intersection cohomology of X\mathcal{X}.

Keywords

Cite

@article{arxiv.2403.15890,
  title  = {Complex algebraic stacks and morphisms of intersection complexes},
  author = {Matthew Huynh},
  journal= {arXiv preprint arXiv:2403.15890},
  year   = {2025}
}

Comments

Final version. Minor changes to exposition. Accepted in Proc. Amer. Math. Soc

R2 v1 2026-06-28T15:31:09.068Z