Higher amalgamation in $\mathrm{ACFA}^{+}$

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Authors: Stefan Marian Ludwig
Cited by: 0

Abstract

We show two results on higher amalgamation in the theory $\mathrm{ACFA}^{+}$, the model companion of the theory of difference fields with an additive character (added as a continuous logic predicate) on the fixed field in characteristic 0. On one hand, we show that the non-trivial condition for 3-amalgamation established in a preceding paper is not sufficient for 4-amalgamation. On the other hand, we show that when working over substructures whose $\mathcal{L}_σ$-reduct is a model of $\mathrm{ACFA}$, $n$-amalgamation holds for all $n\geq 3$.

Fields of Study & Subjects

Advanced Topology and Set Theory Rings Modules and Algebras Advanced Algebra and Logic

Publication details

Journal / source
arXiv (Cornell University)
Publication date
8 January 2026
Document type
Preprint