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Related papers: Kazhdan's Property (T) for Graphs

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We investigate connections between various rigidity and softness properties for discrete quantum groups. After introducing a notion of residual finiteness, we show that it implies the Kirchberg factorization property for the discrete…

Quantum Algebra · Mathematics 2020-07-07 Angshuman Bhattacharya , Michael Brannan , Alexandru Chirvasitu , Shuzhou Wang

For non-amenable finitely generated virtually free groups, we show that the combinatorial Euler characteristic introduced by Emerson and Meyer is the preimage of the K-theory class of higher Kazhdan projections under the Baum-Connes…

Operator Algebras · Mathematics 2025-07-29 Sanaz Pooya , Baiying Ren , Hang Wang

We investigate properties of families $F$ of subsets of a finite set in a situation where subsets are incomparable by the binary inclusion relation and a) for any $A\notin F$, there is such set $A'\in F$ that either $A\subset A'$ or…

Discrete Mathematics · Computer Science 2013-04-17 B. S. Kochkarev

Let $A$ be a finite-dimensional gentle algebra over an algebraically closed field. We investigate the combinatorial properties of support $\tau$-tilting graph of $A$. In particular, it is proved that the support $\tau$-tilting graph of $A$…

Representation Theory · Mathematics 2024-02-15 Changjian Fu , Shengfei Geng , Pin Liu , Yu Zhou

Let $\Theta(G)$ denote the Shannon capacity of a graph $G$. We give an elementary proof of the equivalence, for any graphs $G$ and $H$, of the inequalities $\Theta(G\sqcup H)>\Theta(G)+\Theta(H)$ and $\Theta(G\boxtimes…

Combinatorics · Mathematics 2022-04-15 Alexander Schrijver

We set out some general criteria to prove the K-property, refining the assumptions used in arXiv:1906.09315 for the flow case, and introducing the analogous discrete-time result. We also introduce one-sided $\lambda$-decompositions, as well…

Dynamical Systems · Mathematics 2020-07-02 Benjamin Call

We introduce and study elementary properties of graph homology of algebras. This new homology theory shares many features of cyclic and Hochschild homology. We also define a graph K-theory together with an analog of Chern character.

K-Theory and Homology · Mathematics 2007-05-23 M. V. Movshev

The usual way to investigate the statistical properties of finitely generated subgroups of free groups, and of finite presentations of groups, is based on the so-called word-based distribution: subgroups are generated (finite presentations…

Group Theory · Mathematics 2013-03-21 Frédérique Bassino , Armando Martino , Cyril Nicaud , Enric Ventura , Pascal Weil

We prove the Haagerup property (= Gromov's a-T-menability) for finitely generated groups defined by infinite presentations satisfying the graphical C'(lambda)-small cancellation condition with respect to graphs endowed with a compatible…

Group Theory · Mathematics 2014-10-16 Goulnara Arzhantseva , Damian Osajda

Property A is a form of weak amenability for groups and metric spaces introduced as an approach to the famous Novikov higher signature conjecture, one of the most important unsolved problems in topology. We show that property A can be…

Combinatorics · Mathematics 2021-09-13 G. C. Bell , A. Nagórko

A self-contained exposition is given of the topological and Galois-theoretic properties of the category of combinatorial 1-complexes, or graphs, very much in the spirit of Stallings. A number of classical, as well as some new results about…

Group Theory · Mathematics 2007-05-23 Brent Everitt

We survey the relationship between the combinatorics and geometry of graphs and the algebraic structure of right-angled Artin groups. We concentrate on the defining graph of the right-angled Artin group and on the extension graph associated…

Group Theory · Mathematics 2021-05-03 Thomas Koberda

Let $G$ be a split connected reductive group defined over $\mathbb{Z}$. Let $F$ be a locally compact non-Archimedean field with residue characteristic $p$. For a locally compact non-Archimedean field $F'$ that is sufficiently close to $F$,…

Representation Theory · Mathematics 2025-04-29 Sabyasachi Dhar

We study the properties of a generic object $\mathbb{P}$ in the category of finite graphs. It turns out that this object, being topologically a Cantor set, has the Knaster--Reichbach type property. Namely, every homeomorphism and…

General Topology · Mathematics 2026-02-18 Wiesław Kubiś , Andrzej Kucharski , Sławomir Turek

For each commutative, graded algebra with finite dimension in each degree, we construct a graded cohomology theory for graphs whose graded Euler characteristic is the chromatic polynomial of the graph. This extends our previous work which…

Quantum Algebra · Mathematics 2007-05-23 Laure Helme-Guizon , Yongwu Rong

We give bounds on Kazhdan constants of abelian extensions of (finite) groups. As a corollary, we improved known results of Kazhdan constants for some meta-abelian groups and for the relatively free group in the variety of $p$-groups of…

Group Theory · Mathematics 2010-07-27 Uzy Hadad

In this paper, motivated by our previous work \cite{HY}, we prove that the minimum of the first Dirichlet eigenvalues for the normalized combinatorial $p$-Laplacian on connected finite graphs with boundary consisting of $n$ edges is only…

Combinatorics · Mathematics 2026-03-31 Wankai He , Chengjie Yu

We introduce the graph theoretical parameter of edge treewidth. This parameter occurs in a natural way as the tree-like analogue of cutwidth or, alternatively, as an edge-analogue of treewidth. We study the combinatorial properties of…

Discrete Mathematics · Computer Science 2021-12-15 Loïc Magne , Christophe Paul , Abhijat Sharma , Dimitrios M. Thilikos

We generalize the concept of token graphs to obtain supertoken graphs. In the latter case, there can be more than one token in a vertex. We formally define supertoken graphs and establish their basic properties. Moreover, we provide some…

Combinatorics · Mathematics 2026-04-08 Mónica A. Reyes , Cristina Dalfó , Miquel Àngel Fiol

We exhibit an obstruction for groups with Relative Property (T) to act on the real line by bi-Lipschitz homeomorphisms. This condition is expressed in terms of the Lipschitz and Kazhdan constants associated to finite generating subsets. As…

Group Theory · Mathematics 2026-03-11 Ignacio Vergara