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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 $xy$ is an edge in $E$. Word-representable graphs are the subject of a long research…

Combinatorics · Mathematics 2016-09-20 Alice L. L. Gao , Sergey Kitaev , Philip B. Zhang

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

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 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

Word-representable graphs are a subset of graphs that may be represented by a word $w$ over an alphabet composed of the vertices in the graph. In such graphs, an edge exists if and only if the occurrences of the corresponding vertices…

Data Structures and Algorithms · Computer Science 2025-02-12 Duncan Adamson

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 $xy\in E$. For integers $n>k>0 $, the shift graph $G(n,k)$ is the graph whose vertex set…

Combinatorics · Mathematics 2026-05-25 Suchanda Roy , Ramesh Hariharasubramanian

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 V such that distinct letters x and y alternate in w iff $xy \in E$. We introduce p-complete squares and p-complete square-free word-representable graphs. A word is…

Discrete Mathematics · Computer Science 2025-12-25 Biswajit Das , Ramesh Hariharasubramanian

In this work, we investigate the relationship between $k$-repre\-sentable graphs and graphs representable by $k$-local words. In particular, we show that every graph representable by a $k$-local word is $(k+1)$-representable. A previous…

Combinatorics · Mathematics 2025-06-25 Philipp Böll , Pamela Fleischmann , Annika Huch , Jana Kreiß , Tim Löck , Kajus Park , Max Wiedenhöft

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 $xyxy\cdots$ (of even or odd length) or a word $yxyx\cdots$ (of even or odd length). A graph $G=(V,E)$ is…

Combinatorics · Mathematics 2017-09-29 Sergey Kitaev , Yangjing Long , Jun Ma , Hehui Wu

In this paper, we study the graph induced by the $\textit{2-swap}$ permutation on words with a fixed Parikh vector. A $2$-swap is defined as a pair of positions $s = (i, j)$ where the word $w$ induced by the swap $s$ on $v$ is $v[1] v[2]…

Combinatorics · Mathematics 2024-06-28 Duncan Adamson , Nathan Flaherty , Igor Potapov , Paul G. Spirakis

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 $xy\in E$. Word-representable graphs generalize several important classes of graphs such…

Combinatorics · Mathematics 2023-07-13 Anthony V. Petyuk

A split graph is a graph whose vertex set can be partitioned into a clique and an independent set. The word-representability of split graphs was studied in a series of papers in the literature, and the class of word-representable split…

Combinatorics · Mathematics 2025-04-29 Tithi Dwary , Khyodeno Mozhui , K. V. Krishna

A graph is called $k$-representable if there exists a word $w$ over the nodes of the graph, each node occurring exactly $k$ times, such that there is an edge between two nodes $x,y$ if and only after removing all letters distinct from…

Combinatorics · Mathematics 2018-08-07 Bas Broere , Hans Zantema

Attributes of words and relations between two words are central to numerous tasks in Artificial Intelligence such as knowledge representation, similarity measurement, and analogy detection. Often when two words share one or more attributes…

Computation and Language · Computer Science 2014-12-09 Danushka Bollegala , Takanori Maehara , Yuichi Yoshida , Ken-ichi Kawarabayashi

A graph is said to be word-representable if there exists a word over its vertex set such that any two vertices are adjacent if and only if they alternate in the word. If no such word exists, the graph is non-word-representable. In the…

Combinatorics · Mathematics 2025-09-04 Khyodeno Mozhui , Tithi Dwary , K. V. Krishna

A graph is word-representable if it can be represented in a certain way using alternation of letters in words. Word-representable graphs generalise several important and well-studied classes of graphs, and they can be characterised by…

Combinatorics · Mathematics 2023-06-19 Sergey Kitaev , Haoran Sun

The notion of a $k$-11-representable graph was introduced by Jeff Remmel in 2017 and studied by Cheon et al.\ in 2019 as a natural extension of the extensively studied notion of word-representable graphs, which are precisely…

Combinatorics · Mathematics 2024-07-26 Mikhail Futorny , Sergey Kitaev , Artem Pyatkin

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 $E$. A graph is word-representable if and only if it is…

Combinatorics · Mathematics 2014-03-10 Sergey Kitaev

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 $xy \in E$. In this paper, we prove that any non-empty…

Combinatorics · Mathematics 2026-01-29 Biswajit Das , Ramesh Hariharasubramanian