6 citations · 28 across the 16 of their papers we have counts for
26 papers
Minor exclusion in quasi-transitive graphs
Matthias Hamann
In this note, we show that locally finite quasi-transitive graphs are quasi-isometric to trees if and only if every other locally finite quasi-transitive graph quasi-isometric to t…
Quasi-isometry invariance of hyperbolicity in semimetric spaces, digraphs and semigroups
Matthias Hamann
Gray and Kambites introduced a notion of hyperbolicity in the setting of semimetric spaces like digraphs or semigroups. We will prove that under a small additional geometric assump…
Two characterisations of accessible quasi-transitive graphs
Matthias Hamann, Babak Miraftab
We prove two characterisations of accessibility of locally finite quasi-transitive connected graphs. First, we prove that any such graph is accessible if and only if its set of…
Canonical trees of tree-decompositions
Johannes Carmesin, Matthias Hamann, Babak Miraftab
We prove that every graph has a canonical tree of tree-decompositions that distinguishes all principal tangles (these include the ends and various kinds of large finite dense struc…
Asymptotic dimension of multi-ended quasi-transitive graphs
Matthias Hamann
We prove the existence of an upper bound on the asymptotic dimension of tree amalgamations of locally finite quasi-transitive connected graphs. This generalises a result of Dranish…
Tree amalgamations and hyperbolic boundaries
Matthias Hamann
We look at tree amalgamations of locally finite quasi-transitive hyperbolic graphs and prove that the homeomorphism type of the hyperbolic boundary of such a tree amalgamation only…