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On a purely inseparable analogue ofthe Abhyankar conjecture for affine curves

Part of: Affine geometry Algebraic groups Curves

Published online by Cambridge University Press:  19 July 2018

Shusuke Otabe
Shusuke Otabe*
Affiliation:
Mathematical Institute, Graduate School of Science, Tohoku University, 6-3 Aramakiaza, Aoba, Sendai, Miyagi 980-8578, Japan email shusuke.otabe.r1@dc.tohoku.ac.jp
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Abstract

Let $U$ be an affine smooth curve defined over an algebraically closed field of positive characteristic. The Abhyankar conjecture (proved by Raynaud and Harbater in 1994) describes the set of finite quotients of Grothendieck’s étale fundamental group $\unicode[STIX]{x1D70B}_{1}^{\acute{\text{e}}\text{t}}(U)$. In this paper, we consider a purely inseparable analogue of this problem, formulated in terms of Nori’s profinite fundamental group scheme $\unicode[STIX]{x1D70B}^{N}(U)$, and give a partial answer to it.

Keywords

fundamental group schemestorsorsinverse Galois problem

MSC classification

Primary: 14L15: Group schemes 14R20: Group actions on affine varieties 14H30: Coverings, fundamental group

Information

Type
Research Article
Information
Compositio Mathematica , Volume 154 , Issue 8 , August 2018 , pp. 1633 - 1658
Copyright
© The Author 2018 

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Footnotes

The author is supported by JSPS, Grant-in-Aid for Scientific Research for JSPS fellows (16J02171).

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