English

Characterization of genuine ramification using formal orbifolds

Algebraic Geometry 2024-03-28 v1

Abstract

We give a characterization of genuinely ramified maps of formal orbifolds in the Tannakian framework. In particular we show that a morphism is genuinely ramified if and only if the pullback of every stable bundle remains stable in the orbifold category. We also give some other characterizations of genuine ramification. This generalizes the results of [BKP1] and [BP1]. In fact, it is a positive characteristic analogue of results in [BKP2].

Keywords

Cite

@article{arxiv.2403.18736,
  title  = {Characterization of genuine ramification using formal orbifolds},
  author = {Indranil Biswas and Manish Kumar and A. J. Parameswaran},
  journal= {arXiv preprint arXiv:2403.18736},
  year   = {2024}
}

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Final version

R2 v1 2026-06-28T15:35:48.596Z