English

A 'fat hyperplane section' weak Lefschetz (in arbitrary characteristic), and Barth-type theorems

Algebraic Geometry 2015-02-03 v3 Algebraic Topology

Abstract

We prove a certain 'fat hyperplane section' Weak Lefschetz-type theorem for etale cohomology of non-projective varieties, similar to a result of Goresky and MacPherson (over complex numbers). This statement easily yields certain (vast) generalizations of the 'ordinary' Weak Lefschetz and Barth's theorems in arbitrary characteristic (that do not require any stratified Morse theory for their proof).

Keywords

Cite

@article{arxiv.1203.2595,
  title  = {A 'fat hyperplane section' weak Lefschetz (in arbitrary characteristic), and Barth-type theorems},
  author = {Mikhail V. Bondarko},
  journal= {arXiv preprint arXiv:1203.2595},
  year   = {2015}
}

Comments

Several minor corrections made

R2 v1 2026-06-21T20:32:51.230Z