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A graph is said to be well-covered if all its maximal independent sets are of the same size. In 1999, Yamashita and Kameda introduced a subclass of well-covered graphs, called localizable graphs and defined as graphs having a partition of…

Combinatorics · Mathematics 2017-01-09 Ademir Hujdurović , Martin Milanič , Bernard Ries

Quasi-cliques are dense incomplete subgraphs of a graph that generalize the notion of cliques. Enumerating quasi-cliques from a graph is a robust way to detect densely connected structures with applications to bio-informatics and social…

Data Structures and Algorithms · Computer Science 2020-02-04 Seyed-Vahid Sanei-Mehri , Apurba Das , Srikanta Tirthapura

An identifying code of a graph is a dominating set which uniquely determines all the vertices by their neighborhood within the code. Whereas graphs with large minimum degree have small domination number, this is not the case for the…

Combinatorics · Mathematics 2017-01-02 Florent Foucaud , Guillem Perarnau , Oriol Serra

We prove that every claw-free graph $G$ that doesn't contain a clique on $\Delta(G) \geq 9$ vertices can be $\Delta(G) - 1$ colored.

Combinatorics · Mathematics 2015-08-06 Daniel W. Cranston , Landon Rabern

Intersection graphs are well-studied in the area of graph algorithms. Some intersection graph classes are known to have algorithms enumerating all unlabeled graphs by reverse search. Since these algorithms output graphs one by one and the…

Data Structures and Algorithms · Computer Science 2022-12-15 Jun Kawahara , Toshiki Saitoh , Hirokazu Takeda , Ryo Yoshinaka , Yui Yoshioka

For an integer $t$, a graph $G$ is called {\em{$C_{>t}$-free}} if $G$ does not contain any induced cycle on more than~$t$ vertices. We prove the following statement: for every pair of integers $d$ and $t$ and a CMSO$_2$ statement~$\phi$,…

Data Structures and Algorithms · Computer Science 2021-01-13 Peter Gartland , Daniel Lokshtanov , Marcin Pilipczuk , Michal Pilipczuk , Pawel Rzazewski

Let ${\rm ex \,} {\mathcal B}$ be a minor-closed class of graphs with a set ${\mathcal B}$ of minimal excluded minors. We study (a) the asymptotic number of graphs without $k+1$ disjoint minors in ${\mathcal B}$ and (b) the properties of a…

Combinatorics · Mathematics 2019-07-16 Valentas Kurauskas

In this paper, an effort is made to classify which prime character degree graphs having eight vertices occur for some finite solvable group. To approach this, we compile known results and constructions from the literature which are used to…

Group Theory · Mathematics 2026-04-07 Mark L. Lewis , Andrew Summers

We define a statistical ensemble of non-degenerate graphs, i.e. graphs without multiple- and self-connections between nodes. The node degree distribution is arbitrary, but the nodes are assumed to be uncorrelated. This completes our earlier…

Statistical Mechanics · Physics 2009-11-07 Z. Burda , A. Krzywicki

A connected graph is called of non-QE class if it does not admit a quadratic embedding in a Euclidean space. A non-QE graph is called primary if it does not contain a non-QE graph as an isometrically embedded proper subgraph. The graphs on…

Combinatorics · Mathematics 2023-07-24 Nobuaki Obata

The problem of determining the maximum number of copies of $T$ in an $H$-free graph, for any graphs $T$ and $H$, was considered by Alon and Shikhelman. This is a variant of Tur\'{a}n's classical extremal problem. We show lower and upper…

Combinatorics · Mathematics 2025-03-11 Zhipeng Gao , Ping Li , Changhong Lu , Rui Sun , Long-Tu Yuan

For each integer $n\geq 3$, let $W_n$ denote the wheel graph obtained by connecting a single vertex to all vertices of a cycle of length $n$. In particular, $W_6$ is obtained from the Petersen graph by contracting three edges incident with…

Combinatorics · Mathematics 2026-05-15 Zijun Chen , Yuqi Xu , Weihua Yang

Given a claw-free graph $G=(V,E)$ with maximum degree $\Delta$, we define the parameter $\kappa\in [0,1]$ as $\kappa={\max_{v\in V}|I_v|\over \lfloor\Delta^2/4\rfloor}$ where $I_v$ is the set of all independent pairs in the neighborhood of…

Combinatorics · Mathematics 2026-01-13 Paula M. S. Fialho , Aldo Procacci

If a graph has no induced subgraph isomorphic to $H_1$ or $H_2$ then it is said to be ($H_1,H_2$)-free. Dabrowski and Paulusma found 13 open cases for the question whether the clique-width of ($H_1,H_2$)-free graphs is bounded. One of them…

Discrete Mathematics · Computer Science 2016-08-16 Andreas Brandstadt , Suhail Mahfud , Raffaele Mosca

In this article we present theoretical and computational results on the existence of polyhedral embeddings of graphs. The emphasis is on cubic graphs. We also describe an efficient algorithm to compute all polyhedral embeddings of a given…

Combinatorics · Mathematics 2023-06-22 Gunnar Brinkmann , Thomas Tucker , Nico Van Cleemput

For a given positive integer t we consider graphs having maximal independent sets of precisely t distinct cardinalities and restrict our attention to those that have no vertices of degree one. In the situation when t is four or larger and…

Combinatorics · Mathematics 2011-10-20 Bert L. Hartnell , Douglas F. Rall

A lemma of Fouquet implies that a claw-free graph contains an induced $C_5$, contains no odd hole, or is quasi-line. In this paper we use this result to give an improved shortest-odd-hole algorithm for claw-free graphs by exploiting the…

Discrete Mathematics · Computer Science 2011-05-25 W. Sean Kennedy , Andrew D. King

A {\em hole} in a graph is an induced subgraph which is a cycle of length at least four. A hole is called {\em even} if it has an even number of vertices. An {\em even-hole-free} graph is a graph with no even holes. A vertex of a graph is…

Combinatorics · Mathematics 2020-05-18 Maria Chudnovsky , Paul Seymour

Let $\mathcal{F}$ be a family of fixed graphs and let $d$ be large enough. For every $d$-regular graph $G$, we study the existence of a spanning $\mathcal{F}$-free subgraph of $G$ with large minimum degree. This problem is well-understood…

Combinatorics · Mathematics 2016-12-12 Guillem Perarnau , Bruce Reed

An ordering of the vertices of a graph is \emph{connected} if every vertex (but the first) has a neighbor among its predecessors. The greedy colouring algorithm of a graph with a connected order consists in taking the vertices in order, and…

Discrete Mathematics · Computer Science 2018-06-08 Ngoc Khang Le , Nicolas Trotignon
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