Search results for "20F67"

showing 3 items of 3 documents

Metric equivalences of Heintze groups and applications to classifications in low dimension

2021

We approach the quasi-isometric classification questions on Lie groups by considering low dimensional cases and isometries alongside quasi-isometries. First, we present some new results related to quasi-isometries between Heintze groups. Then we will see how these results together with the existing tools related to isometries can be applied to groups of dimension 4 and 5 in particular. Thus we take steps towards determining all the equivalence classes of groups up to isometry and quasi-isometry. We completely solve the classification up to isometry for simply connected solvable groups in dimension 4, and for the subclass of groups of polynomial growth in dimension 5.

Mathematics - Differential GeometrydifferentiaaligeometriaDifferential Geometry (math.DG)Mathematics - Metric GeometryGeneral MathematicsFOS: MathematicsMathematics::Metric GeometryryhmäteoriaMetric Geometry (math.MG)Group Theory (math.GR)20F67 53C23 22E25 17B70 20F69 30L10 54E40Mathematics - Group Theorymetriset avaruudet
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Automorphisms and abstract commensurators of 2-dimensional Artin groups

2004

In this paper we consider the class of 2-dimensional Artin groups with connected, large type, triangle-free defining graphs (type CLTTF). We classify these groups up to isomorphism, and describe a generating set for the automorphism group of each such Artin group. In the case where the defining graph has no separating edge or vertex we show that the Artin group is not abstractly commensurable to any other CLTTF Artin group. If, moreover, the defining graph satisfies a further `vertex rigidity' condition, then the abstract commensurator group of the Artin group is isomorphic to its automorphism group and generated by inner automorphisms, graph automorphisms (induced from automorphisms of the…

Vertex (graph theory)20F67CommensuratorCoxeter groupCoxeter group20F36InverseGroup Theory (math.GR)Automorphism2–dimensional Artin group20F36 20F55 20F65 20F67CombinatoricsMathematics::Group Theorytriangle freeGenerating set of a groupFOS: Mathematicscommensurator groupArtin groupGeometry and TopologyIsomorphism20F5520F65graph automorphismsMathematics - Group TheoryMathematics
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On the CAT(0) dimension of 2-dimensional Bestvina-Brady groups

2002

Let K be a 2-dimensional finite flag complex. We study the CAT(0) dimension of the `Bestvina-Brady group', or `Artin kernel', Gamma_K. We show that Gamma_K 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.

nonpositive curvatureGroup (mathematics)20F6720F67 57M20Geometric Topology (math.GT)Group Theory (math.GR)Cohomological dimensionEuclidean distanceCombinatoricsKernel (algebra)Mathematics::Group TheoryMathematics - Geometric Topologydimension57M20Dimension (vector space)FOS: MathematicsArtin groupflag complexGeometry and TopologyArtin groupMathematics - Group TheoryZero-dimensional spaceMathematicsFlag (geometry)
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