The local lifting problem for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>ℤ</mml:mi> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> <mml:mi>ℤ</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <mml:mn>3</mml
Let <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>k</mml:mi> </mml:math> be an algebraically closed field of characteristic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mn>2</mml:mn> </mml:math> . In this paper we describe the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>ℤ</mml:mi> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> <mml:mi>ℤ</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <mml:mn>3</mml:mn> </mml:msup> </mml:math> -actions on <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>k</mml:mi> <mml:mo>[</mml:mo> <mml:mo>[</mml:mo> <mml:mi>z</mml:mi> <mml:mo>]</mml:mo> <mml:mo>]</mml:mo> </mml:mrow> </mml:math> for which there is a discrete valuation ring <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>R</mml:mi> </mml:math> , a finite extension of the ring of Witt vectors <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>W</mml:mi> <mml:mo>(</mml:mo> <mml:mi>k</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> , such that they can be lifted as a group of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>R</mml:mi> </mml:math> -automorphisms of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>R</mml:mi> <mml:mo>[</mml:mo> <mml:mo>[</mml:mo> <mml:mi>Z</mml:mi> <mml:mo>]</mml:mo> <mml:mo>]</mml:mo> </mml:mrow> </mml:math> . In fact the necessary and sufficient condition for such an action to lift involves only the conductor type of the corresponding extension.
Authors
- Guillaume Pagot
Publication Details
- Journal
- Journal de Théorie des Nombres de Bordeaux
- Published
- 2025-11-27
- DOI
- https://doi.org/10.5802/jtnb.1344
- Primary Topic
- Algebraic Geometry and Number Theory
- Type
- article
- Field-Weighted Citation Impact
- 0.00