arXiv subjects

Felipe Estrada

Publications and source records attributed to Felipe Estrada.

4 recordsLinked to original sources

arXiv2026

Transitive Extensions of Automorphism Groups of Generic Structures

This work addresses the existence of transitive extensions of certain infinite permutation groups which arise as the automorphism groups of model-theoretic structures which are generic in the Fra\"iss\'e sense. The study of transitive extensions has hitherto largely concerned itself with finite permutation groups. Moving beyond the finite realm, we develop combinatorial tools to prove that transitive extensions exist for edge-colored k-hypergraphs only when the number of colors is a power of two and that transitive extensions exist for k-hypertournaments (in the Cherlin sense) only when k is even, among other results.

math.LO↗

arXiv2026

Quantifier elimination for lovely pairs of strongly geometric fields

Let $T$ be a complete strongly geometric theory of fields with quantifier elimination. We show that the theory of lovely pairs of $T$ has quantifier elimination in Delon's definitional expansion by predicates for linear independence and function symbols for the corresponding coordinate functions. Apart from recovering Delon's original results for pairs of algebraically closed fields and dense pairs of algebraically closed valued fields, we obtain as particular cases, quantifier elimination for theories of dense pairs of real closed and $p$-adically closed fields.

math.LO↗

arXiv2025

Limit Semigroups with 2 Generators

In this paper we study the limit theory of numerical semigroups with two generators. We give a complete axiomatization in some cases.

math.LO↗

arXiv2025

Model Theory of Homogeneous D-sets

We explore several model-theoretic aspects of D-sets, which were studied in detail by Adeleke and Neumann. We characterize ultrahomogeneity in the class of colored D-sets and classify unbounded order-indiscernible sequences in such structures. We use these results to provide a characterization of distal colored D-sets and prove that all colored D-sets with quantifier elimination are dp-minimal.

math.LO↗