Equidimensionality of universal pseudodeformation rings in characteristic p for absolute Galois groups of p-adic fields

Let K be a finite extension of the p-adic field Q𝑝 of degree d, let F be a finite field of characteristic p and let 𝐷 be an n-dimensional pseudocharacter in the sense of Chenevier of the absolute Galois group of K over the field F. For the universal mod p pseudodeformation ring 𝑅univ 𝐷 of 𝐷, we prov...

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Hauptverfasser: Böckle, Gebhard (VerfasserIn) , Juschka, Ann-Kristin (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 17 November 2023
In: Forum of mathematics. Sigma
Year: 2023, Jahrgang: 11, Pages: 1-83
ISSN:2050-5094
DOI:10.1017/fms.2023.82
Online-Zugang:Verlag, kostenfrei, Volltext: https://doi.org/10.1017/fms.2023.82
Verlag, kostenfrei, Volltext: https://www.cambridge.org/core/journals/forum-of-mathematics-sigma/article/equidimensionality-of-universal-pseudodeformation-rings-in-characteristic-p-for-absolute-galois-groups-of-padic-fields/E29626E5A2A247CD54CB5C98F6AB21A5
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Verfasserangaben:Gebhard Böckle and Ann-Kristin Juschka
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Zusammenfassung:Let K be a finite extension of the p-adic field Q𝑝 of degree d, let F be a finite field of characteristic p and let 𝐷 be an n-dimensional pseudocharacter in the sense of Chenevier of the absolute Galois group of K over the field F. For the universal mod p pseudodeformation ring 𝑅univ 𝐷 of 𝐷, we prove the following: The ring 𝑅ps 𝐷 is equidimensional of dimension 𝑑𝑛2 + 1. Its reduced quotient 𝑅univ 𝐷,red contains a dense open subset of regular points x whose associated pseudocharacter 𝐷 𝑥 is absolutely irreducible and nonspecial in a certain technical sense that we shall define. Moreover, we will characterize in most cases when K does not contain a p-th root of unity the singular locus of Spec 𝑅univ 𝐷 . Similar results were proved by Chenevier for the generic fiber of the universal pseudodeformation ring 𝑅univ 𝐷 of 𝐷.
Beschreibung:Gesehen am 10.01.2024
Beschreibung:Online Resource
ISSN:2050-5094
DOI:10.1017/fms.2023.82