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This paper introduces and studies the stability of the strong domination number of a graph, denoted $\operatorname{st}_{\gamma_{st}}(G)$, defined as the minimum number of vertices whose removal changes the strong domination number…

Combinatorics · Mathematics 2026-01-08 Saeid Alikhani , Mazharuddin Mehraban , Hossein Shojaaldini Ardakani

Weak amenability of discrete groups was introduced by Haagerup and co-authors in the 1980's. It is an approximation property known to be stable under direct products and free products. In this paper we show that graph products of weakly…

Group Theory · Mathematics 2017-06-28 Eric Reckwerdt

Conduction graphs are defined here in order to elucidate at a glance the often complicated conduction behaviour of molecular graphs as ballistic molecular conductors. The graph $G^{\mathrm C}$ describes all possible conducting devices…

Combinatorics · Mathematics 2024-09-23 Aidan Birkinshaw , Patrick W. Fowler , Jan Goedgebeur , Jorik Jooken

One of the major results of [N. Robertson and P. D. Seymour. Graph minors. XIII. The disjoint paths problem. J. Combin. Theory Ser. B, 63(1):65--110, 1995], also known as the weak structure theorem, revealed the local structure of graphs…

Combinatorics · Mathematics 2011-03-01 Archontia C. Giannopoulou , Dimitrios M. Thilikos

Chordal graphs are important in the structural and algorithmic graph theory. A digraph analogue of chordal graphs was introduced by Haskin and Rose in 1973 but has not been a subject of active studies until recently when a characterization…

Combinatorics · Mathematics 2021-03-03 Jing Huang , Ying Ying Ye

The weak component generalizes the idea of connected components to directed graphs. In this paper, an exact criterion for existence of the giant weak component is derived for directed graphs with arbitrary bivariate degree distributions. In…

Combinatorics · Mathematics 2016-07-28 Ivan Kryven

A gain graph is a graph whose edges are labelled invertibly by "gains" from a group. "Switching" is a transformation of gain graphs that generalizes conjugation in a group. A "weak chromatic function" of gain graphs with gains in a fixed…

Combinatorics · Mathematics 2010-01-26 Pascal Berthome , Raul Cordovil , David Forge , Veronique Ventos , Thomas Zaslavsky

A graph H is common if the number of monochromatic copies of H in a 2-edge-coloring of the complete graph is asymptotically minimized by the random coloring. The classification of common graphs is one of the most intriguing problems in…

Combinatorics · Mathematics 2022-04-28 Robert Hancock , Daniel Kral , Matjaz Krnc , Jan Volec

The median function is a location/consensus function that maps any profile $\pi$ (a finite multiset of vertices) to the set of vertices that minimize the distance sum to vertices from $\pi$. The median function satisfies several simple…

Combinatorics · Mathematics 2026-02-17 Laurine Bénéteau , Jérémie Chalopin , Victor Chepoi , Yann Vaxès

We consider a class of weakly interacting particle systems of mean-field type. The interactions between the particles are encoded in a graph sequence, i.e., two particles are interacting if and only if they are connected in the underlying…

Probability · Mathematics 2023-07-06 Gianmarco Bet , Fabio Coppini , Francesca R. Nardi

The independent set on a graph $G=(V,E)$ is a subset of $V$ such that no two vertices in the subset have an edge between them. The MIS problem on $G$ seeks to identify an independent set with maximum cardinality, i.e. maximum independent…

Data Structures and Algorithms · Computer Science 2017-05-26 Bhadrachalam Chitturi

\emph{Bidirected graphs} (a sort of nonstandard graphs introduced by Edmonds and Johnson) provide a natural generalization to the notions of directed and undirected graphs. By a \emph{weakly (node- or edge-) acyclic} bidirected graph we…

Combinatorics · Mathematics 2007-05-23 Maxim A. Babenko

Sidorenko's conjecture states that the number of copies of a bipartite graph $H$ in a graph $G$ is asymptotically minimised when $G$ is a quasirandom graph. A notorious example where this conjecture remains open is when $H=K_{5,5}\setminus…

Combinatorics · Mathematics 2020-01-17 Joonkyung Lee , Bjarne Schülke

The weak cop number of infinite graphs can be seen as a coarse-geometric analogue to the cop number of finite graphs. We show that every vertex transitive graph with at least one thick end has infinite weak cop number. It follows that every…

Combinatorics · Mathematics 2025-03-14 Florian Lehner

Stability and dependence are model-theoretic notions that have recently proved highly effective in the study of structural and algorithmic properties of hereditary graph classes, and are considered key notions for generalizing to hereditary…

Combinatorics · Mathematics 2026-04-02 H. Buffière , E. Kim , P. Ossona de Mendez

Let $\Gamma = (\Omega,E)$ be a strongly-regular graph with adjacency matrix $A_1$, and let $A_2$ be the adjacency matrix of its complement. For any vertex $\omega\in \Omega$, we define $E_{0,\omega}^*$ $E_{1,\omega}^*$ and $E_{2,\omega}^*$…

Combinatorics · Mathematics 2025-07-22 Allen Herman , Roghayeh Maleki , Andriaherimanana Sarobidy Razafimahatratra

The theory of graphons comes with the so-called cut norm and the derived cut distance. The cut norm is finer than the weak* topology (when considering the predual of $L^{1}$-functions). Dole\v{z}al and Hladk\'y [J. Combin. Theory Ser. B 137…

Combinatorics · Mathematics 2022-04-19 Martin Doležal , Jan Grebík , Jan Hladký , Israel Rocha , Václav Rozhoň

The main problem in the area of graph property testing is to understand which graph properties are \emph{testable}, which means that with constantly many queries to any input graph $G$, a tester can decide with good probability whether $G$…

Data Structures and Algorithms · Computer Science 2022-05-04 Louis Esperet , Sergey Norin

In this paper, we investigate the dynamical behavior of a two dimensional shift $X_G$ (generated by a two dimensional graph $G=(\mathcal{H},\mathcal{V})$) using the adjacency matrices of the generating graph $G$. In particular, we…

Dynamical Systems · Mathematics 2023-11-03 Prashant Kumar , Puneet Sharma

Weakly separated collections arise in the cluster algebra derived from the Pl\"ucker coordinates on the nonnegative Grassmannian. Oh, Postnikov, and Speyer studied weakly separated collections over a general Grassmann necklace $\mathcal{I}$…

Combinatorics · Mathematics 2016-08-23 Meena Jagadeesan