4 papers
Oligomorphic groups, their automorphism groups, and the complexity of their isomorphism
Gianluca Paolini, Andre Nies
The paper establishes results following two interconnected directions. 1. Let be a Roelcke precompact closed subgroup of the group of permutations of the nat…
On the trivial units property and the unique product property
Heiko Dietrich, Melissa Lee, Andre Nies +1
We report on some computational experiments related to the trivial units property and unique product property for group rings of torsion-free groups. These properties are related t…
Fractal dimensions and profinite groups
Elvira Mayordomo, Andre Nies
Let be a finitely branching rooted tree such that any node has at least two successors. The path space is an ultrametric space: for distinct paths let $d(f,g)= 1/|T…
Automorphism groups of non-Archimedean groups
Andre Nies, Philipp Schlicht
Let $\Aut(G)$ denote the group of (bi-)continuous automorphisms %and $\Out(G)$ the outer automorphism group of a non-Archimedean Polish group~. We show that for any such wit…