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Related papers: On Bredon (Co-)Homological Dimensions of Groups

200 papers

A remarkable result of Gersten states that the class of hyperbolic groups of cohomological dimension $2$ is closed under taking finitely presented (or more generally $FP_2$) subgroups. We prove the analogous result for relatively hyperbolic…

Group Theory · Mathematics 2017-05-31 Eduardo Martinez-Pedroza

Let G be a $p$-adic Lie group. We develop a dimension theory for coadmissible G-equivariant $\mathcal{D}$-modules on smooth rigid analytic spaces. We introduce the category of weakly holonomic G-equivariant $\mathcal{D}$-modules, study its…

Representation Theory · Mathematics 2024-04-15 Tobias Schmidt , Thi Minh Phuong Vu

In this paper we compute the Bredon homology of wallpaper groups with respect to the family of finite groups and with coefficients in the complex representation ring. We provide explicit bases of the homology groups in terms of irreducible…

K-Theory and Homology · Mathematics 2021-11-30 Ramón Flores

In this paper we construct a model for the classifying space, BVCG, of a crystallographic group G of rank n relative to the family VC of virtually-cyclic subgroups of G. The model is used to show that there exists no other model for the…

Algebraic Topology · Mathematics 2007-05-23 Frank Connolly , Benjamin Fehrman , Michael Hartglass

We prove that the Bredon cohomological dimension and the virtual cohomological dimension coincide for groups that admit a cocompact model for $\underline{E}G$ and satisfy properties (M) and (NM). Among the examples of groups satisfying…

Group Theory · Mathematics 2020-10-08 Luis Jorge Sánchez Saldaña

We define the orbit category for transitive topological groupoids and their equivariant CW-complexes. By using these constructions we define equivariant Bredon homology and cohomology for actions of transitive topological groupoids. We show…

Algebraic Topology · Mathematics 2019-11-11 Carla Farsi , Laura Scull , Jordan Watts

A generalization of the double commutator lemma for normal subgroups is shown for invariant random subgroups of a countable group acting faithfully on a Hausdorff space. As an application, we classify ergodic invariant random subgroups of…

Group Theory · Mathematics 2020-01-22 Tianyi Zheng

Let $G$ be a group that admits a cocompact classifying space for proper actions $X$. We derive a formula for the Bredon cohomological dimension for proper actions of $G$ in terms of the relative cohomology with compact support of certain…

Algebraic Topology · Mathematics 2015-03-03 Dieter Degrijse , Conchita Martinez-Perez

Let $k$ be a field. We characterize the group schemes $G$ over $k$, not necessarily affine, such that $\mathsf{D}_{\mathrm{qc}}(B_kG)$ is compactly generated. We also describe the algebraic stacks that have finite cohomological dimension in…

Algebraic Geometry · Mathematics 2016-09-08 Jack Hall , David Rydh

We study the $RO(G)$-graded Bredon cohomology of a point in the case where $G$ is a cyclic group of odd order, expanding on the information provided by previous studies. Our methods center on the purely algebraic aspects of this matter,…

Algebraic Topology · Mathematics 2026-02-24 Daniel Dugger , Christy Hazel

This expository paper explores the interaction of group ordering with topological questions, especially in dimensions 2 and 3. Among the topics considered are surfaces, braid groups, 3-manifolds and their structures such as foliations and…

Algebraic Topology · Mathematics 2014-03-20 Dale Rolfsen

Let $C_n$ denote a cyclic group of order $n$. In this paper we investigate modules and chain complexes over the constant integral Mackey functor $\underline{\mathbb{Z}}$ and perform some related homological calculations. Along the way we…

Algebraic Topology · Mathematics 2026-02-24 Daniel Dugger , Christy Hazel

We study actions of discrete groups on contractible topological spaces in which either (1) all stabilizers lie in the family of subgroups of prime power order or (2) all stabilizers lie in the family of finite subgroups. We compare the…

Group Theory · Mathematics 2009-08-25 Ian J. Leary , Brita E. A. Nucinkis

For a finite group $G$, we define the $G$-cobordism category in dimension two. We show there is a one-to-one correspondence between the connected components of its classifying space and the abelianization of $G$. Also, we find an…

Algebraic Topology · Mathematics 2022-03-08 Carlos Segovia

We study Bredon homology approximations for spaces with an action of a compact Lie group G. We show that if M is a coMackey functor satisfying mild p-locality conditions, then Bredon homology of a G-space X with coefficients in M is…

Algebraic Topology · Mathematics 2020-02-28 Gregory Z. Arone , William G. Dwyer , Kathryn Lesh

We define a family of groups that generalises Thompson's groups $T$ and $G$ and also those of Higman, Stein and Brin. For groups in this family we descrine centralisers of finite subgroups and show, that for a given finite subgroup $Q$,…

Group Theory · Mathematics 2013-09-10 Conchita Martinez-Perez , Brita E. A. Nucinkis

We show that a countable group is locally virtually cyclic if and only if its Bredon cohomological dimension for the family of virtually cyclic subgroups is at most one.

Group Theory · Mathematics 2016-09-27 Dieter Degrijse

Let $\pi$ be a group equipped with an action of a second group $G$ by automorphisms. We define the equivariant cohomological dimension ${\sf cd}_G(\pi)$, the equivariant geometric dimension ${\sf gd}_G(\pi)$, and the equivariant…

Algebraic Topology · Mathematics 2020-04-24 Mark Grant , Ehud Meir , Irakli Patchkoria

We investigate the structure of the minimal displacement set in $8$-located complexes with the SD'-property. We show that such set embeds isometrically into the complex. Since $8$-location and simple connectivity imply Gromov hyperbolicity,…

Group Theory · Mathematics 2021-01-05 Ioana-Claudia Lazăr

Let M be a closed simply connected 2n-dimensional manifold. The present paper is concerned with the cohomology of classifying spaces of connected groups of homeomorphisms of M.

Algebraic Topology · Mathematics 2010-10-15 Jarek Kędra