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The interplay between groups and graphs have been the most famous and productive area of algebraic graph theory. In this paper, we introduce and study the graphs whose vertex set is group G such that two distinct vertices a and b having…

Combinatorics · Mathematics 2019-01-01 Shafiq Ur Rehman , Abdul Qudair Baig , Muhammad Imran , Zia Ullah Khan

We prove that there exists a function $f:\mathbb{N} \rightarrow \mathbb{N}$ such that for any positive integer $k$, if $T$ is a strongly $4k$-connected tournament with minimum out-degree at least $f(k)$, then $T$ is $k$-linked. This makes…

Combinatorics · Mathematics 2019-08-13 António Girão , Richard Snyder

A main question in graphical models and causal inference is whether, given a probability distribution $P$ (which is usually an underlying distribution of data), there is a graph (or graphs) to which $P$ is faithful. The main goal of this…

Statistics Theory · Mathematics 2018-01-30 Kayvan Sadeghi

We investigate the relationship between global offensive $k$-alliances and some characteristic sets of a graph including $r$-dependent sets and $\tau$-dominating sets. As a consequence of the study, we obtain bounds on the global offensive…

Combinatorics · Mathematics 2013-12-02 Sergio Bermudo , Juan A. Rodriguez-Velazquez , Jose M. Sigarreta , Ismael G. Yero

In the List $k$-Coloring problem we are given a graph whose every vertex is equipped with a list, which is a subset of $\{1,\ldots,k\}$. We need to decide if $G$ admits a proper coloring, where every vertex receives a color from its list.…

Combinatorics · Mathematics 2025-09-29 Marta Piecyk , Paweł Rzążewski

This paper considers multiple domination on Kneser graphs. We focus on $k$-tuple dominating sets, $2$-packings and the associated graph parameters $k$-tuple domination number and $2$-packing number. In particular, we compute the $2$-packing…

Combinatorics · Mathematics 2024-04-09 María Gracia Cornet , Pablo Torres

We consider strategic games that are inspired by Schelling's model of residential segregation. In our model, the agents are partitioned into k types and need to select locations on an undirected graph. Agents can be either stubborn, in…

Computer Science and Game Theory · Computer Science 2021-08-24 Edith Elkind , Jiarui Gan , Ayumi Igarashi , Warut Suksompong , Alexandros A. Voudouris

In this note, we give short inductive proofs of two known results on $k$-extendible graphs based on a property proved in [Qinglin Yu, A note on $n$-extendable graphs. Journal of Graph Theory, 16:349-353, 1992].

Combinatorics · Mathematics 2021-10-08 Shenwei Huang , Yongtang Shi

In this article, we investigate the existence of joins in the weak order of an infinite Coxeter group W. We give a geometric characterization of the existence of a join for a subset X in W in terms of the inversion sets of its elements and…

Group Theory · Mathematics 2016-05-10 Christophe Hohlweg , Jean-Philippe Labbé

We study the outcomes of various positions of the game Snort. When played on graphs admitting an automorphism of order two that maps vertices outside of their closed neighbourhoods (called opposable graphs), the second player has a winning…

Combinatorics · Mathematics 2025-06-26 Rylo Ashmore , Beth Ann Austin , Alfie M. Davies , Danny Dyer , William Kellough

We consider a biased version of Maker-Breaker domination games, which were recently introduced by Gledel, Ir{\v{s}}i{\v{c}}, and Klav{\v{z}}ar. Two players, Dominator and Staller, alternatingly claim vertices of a graph $G$ where Dominator…

Combinatorics · Mathematics 2024-08-02 Ali Deniz Bagdas , Dennis Clemens , Fabian Hamann , Yannick Mogge

A set $D$ of vertices in a graph $G$ is a dominating set if every vertex of $G$, which is not in $D$, has a neighbor in $D$. A set of vertices $D$ in $G$ is convex (respectively, isometric), if all vertices in all shortest paths…

Combinatorics · Mathematics 2017-04-28 Boštjan Brešar , Tanja Gologranc , Tim Kos

Threshold graphs are a prevalent and widely studied class of simple graphs. They have several equivalent definitions which makes them a go-to class for finding examples and counter examples when testing and learning. This versatility has…

Combinatorics · Mathematics 2018-03-07 Derek Boeckner

The main goal of this paper is twofold. First, we extend some results known in the case of weak greedy algorithms with a scalar parameter to the case of weak greedy algorithms with a weakness sequence. Second, we formulate a new setting of…

Numerical Analysis · Mathematics 2026-04-30 A. S. Spivak , V. N. Temlyakov

We study oriented graphs whose Hermitian adjacency matrices of the second kind have few eigenvalues. We give a complete characterization of the oriented graphs with two distinct eigenvalues, showing that there are only four such graphs. We…

Combinatorics · Mathematics 2025-12-08 Saieed Akbari , Jonathan Aloni , Maxwell Levit , Bojan Mohar , Steven Xia

We consider the pursuit and evasion game on finite, connected, undirected graphs known as cops and robbers. Meyniel conjectured that for every graph on n vertices a rootish number of cops can win the game. We prove that this holds up to a…

Combinatorics · Mathematics 2008-05-20 Bela Bollobas , Gabor Kun , Imre Leader

There has been recent growing interest in graph theoretical properties known as r- and (r,s)-robustness. These properties serve as sufficient conditions guaranteeing the success of certain consensus algorithms in networks with misbehaving…

Systems and Control · Computer Science 2017-10-06 James Usevitch , Dimitra Panagou

A $(0,1)$-labelling of a set is said to be {\em friendly} if approximately one half the elements of the set are labelled 0 and one half labelled 1. Let $g$ be a labelling of the edge set of a graph that is induced by a labelling $f$ of the…

Combinatorics · Mathematics 2024-04-16 Leroy Beasley , David Brown , Jonathan Mousley , Manuel Santana

We characterize the equivalence and the weak equivalence of Cayley graphs for a finite group $\C{A}$. Using these characterizations, we find degree distribution polynomials for weak equivalence of some graphs including 1) circulant graphs…

Combinatorics · Mathematics 2014-02-18 Dongseok Kim , Young Soo Kwon , Jaeun Lee

In this paper we give tight upper bounds on the total domination number, the weakly connected domination number and the connected domination number of a graph in terms of order and Euler characteristic. We also present upper bounds for the…

Combinatorics · Mathematics 2013-10-08 Vladimir Samodivkin