On definable groups in dp-minimal topological fields equipped with a generic derivation

Abstract

Let $T$ be a complete, model-complete, geometric dp-minimal $\mathcal{L}$-theory of topological fields of characteristic $0$ and let $T(\partial )$ be the theory of expansions of models of $T$ by a derivation $\partial$. We assume that $T(\partial )$ has a model-companion $T_{\partial }$. Let $\hat{I}“$ be a finite-dimensional ${\mathcal{L}}_{\partial }$-definable group in a model of $T_{\partial }$. Then we show that $\hat{I}“$ densely and definably embeds in an $\mathcal{L}$-definable group $G$. Further, using a $C^1$-cell decomposition result, we show that $\hat{I}“$ densely and definably embeds in a definable $D$-group, generalizing the classical construction of Buium of algebraic $D$-groups and extending for that class of fields, results obtained in arXiv:2208.08293, arXiv:2305.16747.