English
Related papers

Related papers: Forbidden patterns of graphs 12-representable by p…

200 papers

A pair of letters $x$ and $y$ are said to alternate in a word $w$ if, after removing all letters except for the copies of $x$ and $y$ from $w$, the resulting word is of the form $xyxy\ldots$ (of even or odd length) or $yxyx\ldots$ (of even…

Combinatorics · Mathematics 2025-07-14 Suchanda Roy , Ramesh Hariharasubramanian

A graph G=(V,E) is representable if there exists a word W over the alphabet V such that letters x and y alternate in W if and only if (x,y) is in E for each x not equal to y. The motivation to study representable graphs came from algebra,…

Combinatorics · Mathematics 2011-08-09 Sergey Kitaev , Pavel Salimov , Christopher Severs , Henning Ulfarsson

A graph $G=(V,E)$ is word-representable if there exists a word $w$ over the alphabet $V$ such that letters $x$ and $y$, $x\neq y$, alternate in $w$ if and only if $(x,y)\in E$. Halld\'{o}rsson et al.\ have shown that a graph is…

Combinatorics · Mathematics 2015-08-03 Thomas Z. Q. Chen , Sergey Kitaev , Brian Y. Sun

There is a long line of research in the literature dedicated to word-representable graphs, which generalize several important classes of graphs. However, not much is known about word-representability of split graphs, another important class…

Combinatorics · Mathematics 2019-09-23 Herman Z. Q. Chen , Sergey Kitaev , Akira Saito

The notion of a 12-representable graph was introduced by Jones et al.. This notion generalizes the notions of the much studied permutation graphs and co-interval graphs. It is known that any 12-representable graph is a comparability graph,…

Combinatorics · Mathematics 2019-11-04 Joanna N. Chen , Sergey Kitaev

A graph $G = (V, E)$ is said to be word-representable if a word $w$ can be formed using the letters of the alphabet $V$ such that for every pair of vertices $x$ and $y$, $xy \in E$ if and only if $x$ and $y$ alternate in $w$. A…

Combinatorics · Mathematics 2026-01-29 Eshwar Srinivasan , Ramesh Hariharasubramanian

Distinct letters $x$ and $y$ alternate in a word $w$ if after deleting in $w$ all letters but the copies of $x$ and $y$ we either obtain a word of the form $xyxy\cdots$ (of even or odd length) or a word of the form $yxyx\cdots$ (of even or…

Combinatorics · Mathematics 2019-07-23 Gi-Sang Cheon , Jinha Kim , Minki Kim , Sergey Kitaev

The notion of word-representable graphs is a generalization of comparability graphs, in which graphs are represented by words. The complexity of word-representation of a word-representable graph is captured through the representation…

Combinatorics · Mathematics 2026-02-17 Khyodeno Mozhui , K. V. Krishna

A graph $G=(V,E)$ is word-representable if there exists a word $w$ over the alphabet $V$ such that letters $x$ and $y$ alternate in $w$ if and only if $(x,y)\in E$. A triangular grid graph is a subgraph of a tiling of the plane with…

Combinatorics · Mathematics 2015-03-30 Zongqing Chen , Sergey Kitaev , Brian Y. Sun

A graph $G=(V,E)$ is word-representable if there exists a word $w$ over the alphabet $V$ such that letters $x$ and $y$ alternate in $w$ if and only if $(x,y)$ is an edge in $E$. Some graphs are word-representable, others are not. It is…

Combinatorics · Mathematics 2014-05-15 Prosper Akrobotu , Sergey Kitaev , Zuzana Masárová

A graph $G = (V, E)$ is word-representable, if there exists a word $w$ over the alphabet $V$ such that for letters $\{x,y\}\in V$, $x$ and $y$ alternate in $w$ if and only if $xy \in E$. A graph is co-bipartite if its complement is a…

Combinatorics · Mathematics 2025-01-20 Biswajit Das , Ramesh Hariharasubramanian

Let $G$ be a simple finite connected graph. The line graph $L(G)$ of graph $G$ is the graph whose vertices are the edges of $G$, where $ef \in E(L(G))$ when $e \cap f \neq \emptyset$. Iteratively, the higher order line graphs are defined…

Combinatorics · Mathematics 2024-10-08 Aryan Sanghi , Devsi Bantva , Sudebkumar Prasant Pal

Series-parallel (SP) graphs are binary edge-labeled graphs with a designated source and target vertex, built using serial and parallel composition. A set of graphs is recognizable if membership depends only on its image under a homomorphism…

Formal Languages and Automata Theory · Computer Science 2026-04-28 Marius Bozga , Radu Iosif , Florian Zuleger

A graph $G = (V,E)$ is word-representable if there is a word $w$ over the alphabet $V$ such that $x$ and $y$ alternate in $w$ if and only if the edge $(x, y)$ is in $G$. It is known [6] that all $3$-colourable graphs are word-representable,…

Combinatorics · Mathematics 2018-10-01 Marc Elliot Glen

In this work, we show that the class of word-representable graphs is closed under split recomposition and determine the representation number of the graph obtained by recomposing two word-representable graphs. Accordingly, we show that the…

Discrete Mathematics · Computer Science 2024-01-05 Tithi Dwary , K. V. Krishna

In the course of proving the strong perfect graph theorem, Chudnovsky, Robertson, Seymour, and Thomas showed that every perfect graph either belongs to one of five basic classes or admits one of several decompositions. Four of the basic…

Combinatorics · Mathematics 2012-03-05 Boris Alexeev , Alexandra Fradkin , Ilhee Kim

The undirected power graph (or simply power graph) of a group $G$, denoted by $P(G)$, is a graph whose vertices are the elements of the group $G$, in which two vertices $u$ and $v$ are connected by an edge between if and only if either…

Combinatorics · Mathematics 2023-05-09 Pallabi Manna , Peter J. Cameron , Ranjit Mehatari

In this work, we characterize the class of word-representable graphs with respect to the modular decomposition. Consequently, we determine the representation number of a word-representable graph in terms of the permutation-representation…

Combinatorics · Mathematics 2024-12-24 Tithi Dwary , K. V. Krishna

The undirected power graph (or simply power graph) of a group $G$, denoted by $P(G)$, is a graph whose vertices are the elements of the group $G$, in which two vertices $u$ and $v$ are adjacent if and only if either $u=v^m$ or $v=u^n$ for…

Combinatorics · Mathematics 2023-09-04 Santanu Mandal , Pallabi Manna

A graph $G = (V, E)$ is said to be word-representable if a word $w$ can be formed using the letters of the alphabet $V$ such that for every pair of vertices $x$ and $y$, $xy \in E$ if and only if $x$ and $y$ alternate in $w$. Gaetz and Ji…

Combinatorics · Mathematics 2025-12-25 Eshwar Srinivasan , Ramesh Hariharasubramanian