Results 11 to 20 of about 339 (75)
Curve graphs for Artin–Tits groups of type B, A∼ and C∼ are hyperbolic
Abstract The graph of irreducible parabolic subgroups is a combinatorial object associated to an Artin–Tits group A defined so as to coincide with the curve graph of the (n+1)‐times punctured disk when A is Artin's braid group on (n+1) strands. In this case, it is a hyperbolic graph, by the celebrated Masur–Minsky's theorem.
Matthieu Calvez+1 more
wiley +1 more source
Correlations in totally symmetric self‐complementary plane partitions
Abstract Totally symmetric self‐complementary plane partitions (TSSCPPs) are boxed plane partitions with the maximum possible symmetry. We use the well‐known representation of TSSCPPs as a dimer model on a honeycomb graph enclosed in 1/12 of a hexagon with free boundary to express them as perfect matchings of a family of non‐bipartite planar graphs ...
Arvind Ayyer, Sunil Chhita
wiley +1 more source
Coloring the Voronoi tessellation of lattices
Abstract In this paper we define the chromatic number of a lattice: It is the least number of colors one needs to color the interiors of the cells of the Voronoi tessellation of a lattice so that no two cells sharing a facet are of the same color. We compute the chromatic number of the root lattices, their duals, and of the Leech lattice, we consider ...
Mathieu Dutour Sikirić+3 more
wiley +1 more source
Deforming cubulations of hyperbolic groups
Abstract We describe a procedure to deform cubulations of hyperbolic groups by ‘bending hyperplanes’. Our construction is inspired by related constructions like Thurston's Mickey Mouse example, walls in fibred hyperbolic 3‐manifolds and free‐by‐Z groups, and Hsu–Wise turns.
Elia Fioravanti, Mark Hagen
wiley +1 more source
A new obstruction for normal spanning trees
Abstract In a paper from 2001 (Journal of the LMS), Diestel and Leader offered a proof that a connected graph has a normal spanning tree if and only if it has no minor obtained canonically from either an (ℵ0,ℵ1)‐regular bipartite graph or an order‐theoretic Aronszajn tree. In particular, this refuted an earlier conjecture of Halin's that only the first
Max Pitz
wiley +1 more source
Sparse Kneser graphs are Hamiltonian
Abstract For integers k⩾1 and n⩾2k+1, the Kneser graph K(n,k) is the graph whose vertices are the k‐element subsets of {1,…,n} and whose edges connect pairs of subsets that are disjoint. The Kneser graphs of the form K(2k+1,k) are also known as the odd graphs.
Torsten Mütze+2 more
wiley +1 more source
(Un)distorted stabilisers in the handlebody group
Abstract We study geometric properties of stabilisers in the handlebody group. We find that stabilisers of meridians are undistorted, while stabilisers of primitive curves or annuli are exponentially distorted for large enough genus.
Sebastian Hensel
wiley +1 more source
Quasi‐isometric diversity of marked groups
Abstract We use basic tools of descriptive set theory to prove that a closed set S of marked groups has 2ℵ0 quasi‐isometry classes, provided that every non‐empty open subset of S contains at least two non‐quasi‐isometric groups. It follows that every perfect set of marked groups having a dense subset of finitely presented groups contains 2ℵ0 quasi ...
A. Minasyan, D. Osin, S. Witzel
wiley +1 more source
The extremal number of longer subdivisions
Abstract For a multigraph F, the k‐subdivision of F is the graph obtained by replacing the edges of F with pairwise internally vertex‐disjoint paths of length k+1. Conlon and Lee conjectured that if k is even, then the (k−1)‐subdivision of any multigraph has extremal number O(n1+1k), and moreover, that for any simple graph F there exists ε>0 such that ...
Oliver Janzer
wiley +1 more source
Injectivity results for coarse homology theories
Abstract We show injectivity results for assembly maps using equivariant coarse homology theories with transfers. Our method is based on the descent principle and applies to a large class of linear groups or, more generally, groups with finite decomposition complexity.
Ulrich Bunke+3 more
wiley +1 more source