Automorphisms of Harbater–Katz–Gabber curves
Name
1509.02139.pdf
Description
Accepted version
Size
358.17 KB
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Unknown
Checksum (MD5)
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Author(s)
Bleher, Frauke M
Chinburg, Ted
Poonen, Bjorn
Symonds, Peter
Date Issued
2017
Journal
Mathematische Annalen
Publisher
Springer Nature
Citation
Bleher, F. M., et al. "Automorphisms of Harbater�Katz�Gabber Curves." Mathematische Annalen (2016): 1-26.
Version
Author's final manuscript
Abstract
© 2016, Springer-Verlag Berlin Heidelberg. Let k be a perfect field of characteristic p> 0 , and let G be a finite group. We consider the pointed G-curves over k associated by Harbater, Katz, and Gabber to faithful actions of G on k[[t]] over k. We use such “HKG G-curves” to classify the automorphisms of k[[t]] of p-power order that can be expressed by particularly explicit formulas, namely those mapping t to a power series lying in a Z/ pZ Artin–Schreier extension of k(t). In addition, we give necessary and sufficient criteria to decide when an HKG G-curve with an action of a larger finite group J is also an HKG J-curve.
MIT Department
Massachusetts Institute of Technology. Department of Mathematics
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1007/S00208-016-1490-2
