Remarks on weak amalgamation and large conjugacy classes in non-archimedean groups

Abstract We study the notion of weak amalgamation in context diagonal conjugacy classes. Generalizing results Kechris and Rosendal, we prove that for every countable structure M , Polish group G permutations $$n \ge 1$$ n ≥ 1 has a comeager n -diagonal class iff family all -tuples -extendable bijections between finitely generated substructures joint embedding property property. characterize limits Fraïssé classes are not homogenizable. Finally, investigate 1- 2-diagonal groups ball-preserving certain ordered ultrametric spaces.