Let K be a 2–dimensional finite flag complex. We study the CAT(0) dimension of the ‘Bestvina–Brady group’, or ‘Artin kernel’, ΓK. We show that ΓK has CAT(0) dimension 3 unless K admits a piecewise Euclidean metric of non-positive curvature. We give an example to show that this implication cannot be reversed. Different choices of K lead to examples where the CAT(0) dimension is 3, and either (i) the geometric dimension is 2, or (ii) the cohomological dimension is 2 and the geometric dimension is not known.
Crisp, John  1
@article{10_2140_agt_2002_2_921,
author = {Crisp, John},
title = {On the {CAT(0)} dimension of 2{\textendash}dimensional {Bestvina{\textendash}Brady} groups},
journal = {Algebraic and Geometric Topology},
pages = {921--936},
year = {2002},
volume = {2},
number = {2},
doi = {10.2140/agt.2002.2.921},
url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2002.2.921/}
}
TY - JOUR AU - Crisp, John TI - On the CAT(0) dimension of 2–dimensional Bestvina–Brady groups JO - Algebraic and Geometric Topology PY - 2002 SP - 921 EP - 936 VL - 2 IS - 2 UR - http://geodesic.mathdoc.fr/articles/10.2140/agt.2002.2.921/ DO - 10.2140/agt.2002.2.921 ID - 10_2140_agt_2002_2_921 ER -
Crisp, John. On the CAT(0) dimension of 2–dimensional Bestvina–Brady groups. Algebraic and Geometric Topology, Tome 2 (2002) no. 2, pp. 921-936. doi: 10.2140/agt.2002.2.921
[1] , , Morse theory and finiteness properties of groups, Invent. Math. 129 (1997) 445
[2] , private communication (2002)
[3] , , Two-dimensional Artin groups with $\mathrm{CAT}(0)$ dimension three, from: "Proceedings of the Conference on Geometric and Combinatorial Group Theory, Part I (Haifa, 2000)" (2002) 185
[4] , On the existence of flat planes in spaces of nonpositive curvature, Proc. Amer. Math. Soc. 123 (1995) 223
[5] , Length functions, curvature and the dimension of discrete groups, Math. Res. Lett. 8 (2001) 557
[6] , , Metric spaces of non-positive curvature, Grundlehren der Mathematischen Wissenschaften 319, Springer (1999)
[7] , Cohomology of groups, Graduate Texts in Mathematics 87, Springer (1982)
[8] , , Presentations for subgroups of Artin groups, Proc. Amer. Math. Soc. 127 (1999) 343
[9] , , On the Lusternik–Schnirelmann category of abstract groups, Ann. of Math. $(2)$ 65 (1957) 517
[10] , , Dimension Theory, Princeton Mathematical Series, v. 4, Princeton University Press (1941)
[11] , On torsion-free groups with infinitely many ends, Ann. of Math. $(2)$ 88 (1968) 312
[12] , Groups of cohomological dimension one, J. Algebra 12 (1969) 585
[13] , The Homotopy Type of Complex Hyperplane Complements, PhD thesis, University of Nijmegen (1983)
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