Searcharxiv⌕ Search

arXiv subjects

Vítor Araújo

Publications and source records attributed to Vítor Araújo.

3 recordsLinked to original sources

Hölder conditions for endomorphisms of hyperbolic groups

It is proved that an endomorphism $φ$ of a hyperbolic group $G$ satisfies a Hölder condition with respect to a visual metric if and only if $φ$ is virtually injective and $Gφ$ is a quasiconvex subgroup of $G$. If $G$ is virtually free or torsion-free co-hopfian, then $φ$ is uniformly continuous if and only if it it satisfies a Hölder condition if and only if it is virtually injective. Lipschitz conditions are discussed for free group automorphisms.

math.GR↗

Geometric characterizations of virtually free groups

Four geometric conditions on a geodesic metric space, which are stronger variants of classical conditions characterizing hyperbolicity, are proved to be equivalent. In the particular case of the Cayley graph of a finitely generated group, it is shown that they characterize virtually free groups.

math.GR↗