English

\'Etale cohomology of a DM curve-stack with coefficients in G_m

Algebraic Geometry 2014-08-28 v2

Abstract

We compute the \'etale cohomology groups H^i(X,G_m) in several cases, where X is a smooth tame Deligne-Mumford stack of dimension 1 over an algebraically closed field. We have complete results for orbicurves (and, more generally, for twisted nodal curves) and in the case all stabilizers are cyclic; we give some partial results and examples in the general case. In particular we show that if the stabilizers are abelian then H^2(X, G_m) does not depend on X but only on the underlying orbicurve and on the generic stabilizer.

Keywords

Cite

@article{arxiv.1008.0538,
  title  = {\'Etale cohomology of a DM curve-stack with coefficients in G_m},
  author = {Flavia Poma},
  journal= {arXiv preprint arXiv:1008.0538},
  year   = {2014}
}

Comments

13 pages, comments welcome