Distality in valued fields and related structures

M Aschenbrenner, A Chernikov, A Gehret… - Transactions of the …, 2022 - ams.org
We investigate distality and existence of distal expansions in valued fields and related
structures. In particular, we characterize distality in a large class of ordered abelian groups …

Undecidability in some field theories

B Tyrrell - 2023 - ora.ox.ac.uk
This thesis is a study of undecidability in some field theories. Specifically, we are interested
in geometrically oriented problems and have focused our attention in two directions along …

The model theory of Cohen rings

S Anscombe, F Jahnke - Confluentes Mathematici, 2022 - numdam.org
The aim of this article is to give a self-contained account of the algebra and model theory of
Cohen rings, a natural generalization of Witt rings. Witt rings are only valuation rings in case …

Finite undecidability in NIP fields

B Tyrrell - The Journal of Symbolic Logic, 2023 - cambridge.org
A field K in a ring language. We extend a construction of Ziegler and (among other results)
use a first-order classification of Anscombe and Jahnke to prove every NIP henselian …

Dp-finite and Noetherian NIP integral domains

W Johnson - arXiv preprint arXiv:2302.03315, 2023 - arxiv.org
We prove some results on NIP integral domains, especially those that are Noetherian or
have finite dp-rank. If $ R $ is an NIP Noetherian domain that is not a field, then $ R $ is a …

Beyond the Fontaine-Wintenberger theorem

F Jahnke, K Kartas - arXiv preprint arXiv:2304.05881, 2023 - arxiv.org
Given a perfectoid field, we find an elementary extension and a henselian defectless
valuation on it, whose value group is divisible and whose residue field is an elementary …

Henselian expansions of NIP fields

F Jahnke - Journal of Mathematical Logic, 2024 - World Scientific
Let K be an NIP field and let v be a Henselian valuation on K. We ask whether (K, v) is NIP
as a valued field. By a result of Shelah, we know that if v is externally definable, then (K, v) is …

Dp-finite fields V: topological fields of finite weight

W Johnson - arXiv preprint arXiv:2004.14732, 2020 - arxiv.org
We prove that unstable dp-finite fields admit definable V-topologies. As a consequence, the
henselianity conjecture for dp-finite fields implies the Shelah conjecture for dp-finite fields …

When does NIP transfer from fields to henselian expansions?

F Jahnke - arXiv preprint arXiv:1607.02953, 2016 - arxiv.org
Let $ K $ be an NIP field and let $ v $ be a henselian valuation on $ K $. We ask whether
$(K, v) $ is NIP as a valued field. By a result of Shelah, we know that if $ v $ is externally …

Henselianity in NIP 𝔽p-algebras

W Johnson - Model Theory, 2022 - msp.org
We prove an assortment of results on (commutative and unital) NIP rings, especially 𝔽 p-
algebras. Let R be a NIP ring. Then every prime ideal or radical ideal of R is externally …