English

The singular locus of hypersurface sections containing a closed subscheme over finite fields

Number Theory 2017-04-27 v1

Abstract

We prove that there exist hypersurfaces that contain a given closed subscheme ZZ of the projective space over a finite field and intersect a given smooth scheme XX off of ZZ smoothly, if the intersection V=ZXV = Z \cap X is smooth. Furthermore, we can give a bound on the dimension of the singular locus of the hypersurface section and prescribe finitely many local conditions on the hypersurface. This is an analogue of a Bertini theorem of Bloch over finite fields and is proved using Poonen's closed point sieve. We also show a similar theorem for the case where VV is not smooth.

Keywords

Cite

@article{arxiv.1704.08108,
  title  = {The singular locus of hypersurface sections containing a closed subscheme over finite fields},
  author = {Franziska Wutz},
  journal= {arXiv preprint arXiv:1704.08108},
  year   = {2017}
}