Conformal dimension of hyperbolic groups that split over elementary subgroups

Lower bound on growth of non-elementary subgroups in relatively hyperbolic groups

This paper proves that in a non-elementary relatively hyperbolic group, the logarithm growth rate of any non-elementary subgroup has a linear lower bound by the logarithm of the size of the corresponding generating set. As a consequence, any non-elementary subgroup has uniform exponential growth.

Endomorphisms of relatively hyperbolic groups

We generalize some results of Paulin and Rips-Sela on endomorphisms of hyperbolic groups to relatively hyperbolic groups, and in particular prove the following. (1) If G is a finitely generated non-elementary relatively hyperbolic group with slender parabolic subgroups, and either G is not co-Hopfian or Out(G) is infinite, then G splits over a slender group. (2) If a finitely generated non-parabolic subgroup H of a non-elementary relatively hyperbolic group is not Hopfian, then H acts non-trivially on an R-tree. (3) Every non-elementary relatively hyperbolic group has a non-elementary relative…

右角Artin群的粗分离与分解

Coarse separation and splittings in right-angled Artin groups

本文研究了右角Artin群在abelian子群上的分解条件，证明群分解当且仅当图Γ是完全图或由完全子图分离。