English

Torsion in the 0-cycle group with modulus

Algebraic Geometry 2018-02-19 v2

Abstract

We show, for a smooth projective variety XX over an algebraically closed field kk with an effective Cartier divisor DD, that the torsion subgroup \CH0(XD){l}\CH_0(X|D)\{l\} can be described in terms of a relative {\'e}tale cohomology for any prime lp=char(k)l \neq p = {\rm char}(k). This extends a classical result of Bloch, on the torsion in the ordinary Chow group, to the modulus setting. We prove the Roitman torsion theorem (including pp-torsion) for \CH0(XD)\CH_0(X|D) when DD is reduced. We deduce applications to the problem of invariance of the prime-to-pp torsion in \CH0(XD)\CH_0(X|D) under an infinitesimal extension of DD.

Keywords

Cite

@article{arxiv.1607.01493,
  title  = {Torsion in the 0-cycle group with modulus},
  author = {Amalendu Krishna},
  journal= {arXiv preprint arXiv:1607.01493},
  year   = {2018}
}

Comments

Final version, title changed, 32 pages, to appear in Algebra \& Number Theory journal

R2 v1 2026-06-22T14:46:41.192Z