Let E¯¯G be the classifying space of G for the family of virtually cyclic subgroups. We show that an Artin group admits a finite model for E¯¯G if and only if it is virtually cyclic. This solves a conjecture of Juan-Pineda and Leary and a question of Lück, Reich, Rognes and Varisco for Artin groups. We then study conjugacy growth of CAT(0) groups and show that if a CAT(0) group contains a free abelian group of rank two, its conjugacy growth is strictly faster than linear. This also yields an alternative proof for the fact that a CAT(0) cube group admits a finite model for E¯ ¯G if and only if it is virtually cyclic. Our last result deals with the homotopy type of the quotient space B¯ ¯G = E¯¯G∕G. We show, for a poly-ℤ–group G, that B¯ ¯G is homotopy equivalent to a finite CW–complex if and only if G is cyclic.
Keywords: finiteness properties of groups for families of subgroups, Artin groups, conjugacy growth, CAT(0) cube group, virtually cyclic groups, poly-$\mathbb{Z}$–groups
von Puttkamer, Timm  1 ; Wu, Xiaolei  2
@article{AGT_2020_20_6_a3,
author = {von Puttkamer, Timm and Wu, Xiaolei},
title = {Some results related to finiteness properties of groups for families of subgroups},
journal = {Algebraic and Geometric Topology},
pages = {2885--2904},
year = {2020},
volume = {20},
number = {6},
url = {http://geodesic.mathdoc.fr/item/AGT_2020_20_6_a3/}
}
TY - JOUR AU - von Puttkamer, Timm AU - Wu, Xiaolei TI - Some results related to finiteness properties of groups for families of subgroups JO - Algebraic and Geometric Topology PY - 2020 SP - 2885 EP - 2904 VL - 20 IS - 6 UR - http://geodesic.mathdoc.fr/item/AGT_2020_20_6_a3/ ID - AGT_2020_20_6_a3 ER -
von Puttkamer, Timm; Wu, Xiaolei. Some results related to finiteness properties of groups for families of subgroups. Algebraic and Geometric Topology, Tome 20 (2020) no. 6, pp. 2885-2904. http://geodesic.mathdoc.fr/item/AGT_2020_20_6_a3/
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