English

Algebraic fibrations of certain hyperbolic 4-manifolds

Geometric Topology 2020-01-14 v1

Abstract

Algebraically fibering group is an algebraic generalization of the fibered 3-manifold group in higher dimensions. Let M(P)M(\mathcal{P}) and M(E)M(\mathcal{E}) be the cusped and compact hyperbolic real moment-angled manifolds associated to the hyperbolic right-angled 24-cell P\mathcal{P} and the hyperbolic right-angled 120-cell E\mathcal{E}, respectively. Jankiewicz-Norin-Wise showed in [13] that π1(M(P))\pi_1(M(\mathcal{P})) and π1(M(E))\pi_1(M(\mathcal{E})) are algebraic fibered. Namely, there are two exact sequences 1HPπ1(M(P))ϕPZ1,1\rightarrow H_{\mathcal{P}}\rightarrow \pi_1(M(\mathcal{P}))\xrightarrow{\phi_{\mathcal{P}}} \mathbb{Z}\rightarrow 1, 1HEπ1(M(E))ϕEZ1,1\rightarrow H_{\mathcal{E}}\rightarrow \pi_1(M(\mathcal{E}))\xrightarrow{\phi_{\mathcal{E}}} \mathbb{Z}\rightarrow 1, where HPH_{\mathcal{P}} and HEH_{\mathcal{E}} are finitely generated. In this paper, we furtherly show that the groups HPH_{\mathcal{P}} and HEH_{\mathcal{E}} are not FP2FP_2. In particular, those fiber-kernel groups are finitely generated, but not finitely presented.

Keywords

Cite

@article{arxiv.2001.04048,
  title  = {Algebraic fibrations of certain hyperbolic 4-manifolds},
  author = {Jiming Ma and Fangting Zheng},
  journal= {arXiv preprint arXiv:2001.04048},
  year   = {2020}
}
R2 v1 2026-06-23T13:09:14.172Z