collaborators

16 papers

math.DS2026

Corrigendum and addendum to "Fixed-point-free elements of iterated monodromy groups" [Trans. of the American Mathematical Society Vol. 367, No. 3 (2015), 2023-2049]

Jorge Fariña-Asategui, Rafe Jones, Santiago Radi

In this note we document a gap in an argument in the above paper, and point to new work in the literature giving a complete proof of the main result.

math.NT2026

Arboreal Galois representations of rational functions: fixed-point proportion and the extension problem

Jorge Fariña-Asategui

We give an explicit description of the arithmetic-geometric extension of iterated Galois groups of rational functions. This yields a complete solution to the extension problem when…

math.GR2026

Virtual retracts in groups acting on rooted trees

Jorge Fariña-Asategui, Jon Merladet Urigüen

We study virtual retracts in groups acting on rooted trees. We show that finitely generated branch groups do not have the local retraction (LR) property. Furthermore, we specialize…

math.NT2026

Fixed-point proportion of geometric iterated Galois groups

Jorge Fariña-Asategui, Santiago Radi

In 1980, Odoni initiated the study of the fixed-point proportion of iterated Galois groups of polynomials motivated by prime density problems in arithmetic dynamics. The main goal…

math.GR2025

Non-closed subgroups of weakly branch groups

Jorge Fariña-Asategui, Paul-Henry Leemann, Tatiana Nagnibeda

For a weakly branch group acting on a regular enough rooted tree, we provide two constructions of continuous families of distinct subgroups that are not closed in the profinite…

math.GR2025

Random subgroups of branch groups

Jorge Fariña-Asategui, Santiago Radi

We show that independent Haar-random elements in a super strongly fractal branch profinite group generate a free subgroup acting freely on the boundary of the tree. This improves a…