On the homotopy exact sequence for Nori's fundamental group

Hélène Esnault; Phùng Hô Hai; Eckart Viehweg

On the homotopy exact sequence for Nori's fundamental group

Algebraic Geometry 2010-06-07 v3

Authors: Hélène Esnault , Phùng Hô Hai , Eckart Viehweg

Abstract

Unlike Grothendieck's \'etale fundamental group, Nori's fundamental group does not fulfill the homotopy exact sequence in general. We give necessary and sufficient conditions which force exactness of the sequence.

Keywords

Nori's fundamental group homotopy exact sequence étale fundamental group algebraic geometry exactness conditions

Cite

@article{arxiv.0908.0498,
  title  = {On the homotopy exact sequence for Nori's fundamental group},
  author = {Hélène Esnault and Phùng Hô Hai and Eckart Viehweg},
  journal= {arXiv preprint arXiv:0908.0498},
  year   = {2010}
}

Comments

Lei Zhang found a gap in the proof of Proposition 3.4. We withdraw the article, at least for the time being

On the homotopy exact sequence for Nori's fundamental group

Abstract

Keywords

Cite

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