3 papers
math.LO2026
Definability via the tilting correspondence
Gessica Alecci, Ihsane Hadeg, Franziska Jahnke +2
We show that arithmetic definability of henselian valuations is preserved by the tilting correspondence. Moreover, we show that if a perfectoid valuation is arithmetically definabl…
math.LO2026
Composition Ax-Kochen/Ershov principles and tame fields of mixed characteristic
Margarete Ketelsen, Philip Dittmann
We study in which settings we have a composition AKE principle, i.e. when the theory of the coarsening and the theory of the induced valuation determine…
math.LO2025
Definable henselian valuations in positive residue characteristic
Margarete Ketelsen, Simone Ramello, Piotr Szewczyk
We study the question of -definability of non-trivial henselian valuation rings. Building on previous work of Jahnke and Koenigsmann, we provide a char…