On groups whose geodesic growth is polynomial

This note records some observations concerning geodesic growth functions. If a nilpotent group is not virtually cyclic then it has exponential geodesic growth with respect to all finite generating sets. On the other hand, if a finitely generated group $G$ has an element whose normal closure is abelian and of finite index, then $G$ has a finite generating set with respect to which the geodesic growth is polynomial (this includes all virtually cyclic groups).Comment: 11 pages, 1 figur

Geodesic growth in virtually abelian groups

We show that the geodesic growth function of any finitely generated virtually abelian group is either polynomial or exponential; and that the geodesic growth series is holonomic, and rational in the polynomial growth case. In addition, we show that the language of geodesics is blind multicounter.Comment: 23 pages, 1 figure, improved readabilit

Some geometric groups with rapid decay

We explain some simple methods to establish the property of Rapid Decay for a number of groups arising geometrically. We also give new examples of groups with the property of Rapid Decay. In particular we establish the property of Rapid Decay for all lattices in rank one Lie groups.Comment: 30 pages, 0 figures. There is a change in the content of the paper. The statement of Theorem 0.5 involving cube complexes in the original version fo the paper was incorrect. There is a change in the content of the paper. The proof of Lemma 2.10 needed the use of a result in Drutu-Sapir. This was pointed out to us by D. Groves. The paper has been accepted by GAFA for publicatio