2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/168404Based on the work of Abercrombie, Barnea and Shalev gave an explicit formula for the Hausdorff dimension of a group acting on a rooted tree. We focus here on the binary tree T. Abert and Virag showed that there exist finitely generated (but not necessarily level-transitive) subgroups of AutT of arbitrary dimension in [0,1]. In this article we explicitly compute the Hausdorff dimension of the level-transitive spinal groups. We then show examples of 3-generated spinal groups which have transcendental Hausdroff dimension, and exhibit a construction of 2-generated groups whose Hausdorff dimension is 1.10 pages; full revision; simplified some proofsGroup Theory20E08 (Primary); 28A78 (Secondary)Hausdorff dimension of some groups acting on the binary treetext