3 citations · 7 across the 10 of their papers we have counts for
9 papers · 1 filter
Scale and tidy subgroups for Weyl-transitive automorphism groups of buildings
Udo Baumgartner, James Parkinson, Jacqui Ramagge
We consider closed, Weyl-transitive groups of automorphisms of thick buildings. For each element of such a group, we derive a combinatorial formula for its scale and establish the…
Scale-multiplicative semigroups and geometry: automorphism groups of trees
Udo Baumgartner, Jacqui Ramagge, George A. Willis
A scale-multiplicative semigroup in a totally disconnected, locally compact group is one for which the restriction of the scale function on is multiplicative. The maximal s…
Hyperbolic groups have flat-rank at most 1
Udo Baumgartner, Rögnvaldur G. Möller, George A. Willis
The flat-rank of a totally disconnected, locally compact group G is an integer, which is an invariant of G as a topological group. We generalize the concept of hyperbolic groups to…
Geometric characterization of flat groups of automorphisms
Udo Baumgartner, Günter Schlichting, George A. Willis
If H is a flat group of automorphisms of finite rank n of a totally disconnected, locally compact group G, then each orbit of H in the metric space B(G) of compact, open subgroups…
Contraction groups in complete Kac-Moody groups
Udo Baumgartner, Jacqui Ramagge, Bertrand Remy
Let be an abstract Kac-Moody group over a finite field and be the closure of the image of in the automorphism group of its positive building. We show that if the…
Scales for co-compact embeddings of virtually free groups
Udo Baumgartner
Let be a group which is virtually free of rank at least 2 and let be the family of totally disconnected, locally compact groups containing as a co-com…