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Related papers: New results on word-representable graphs

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A word-graph Gw is a digraph represented by a word w such that the vertex-set V(Gw) is the alphabet of w and the edge-set E(Gw) is determined by non-identical adjacent letter pairs in w. In this paper we study the strong-connectivity of…

Combinatorics · Mathematics 2011-08-31 Edward J. L. Bell , Damon Berridge , Paul Rayson

In this paper we study graphs defined by pattern-avoiding words. Word-representable graphs have been studied extensively following their introduction in 2000 and are the subject of a book published by Kitaev in 2015. Recently there has been…

Combinatorics · Mathematics 2016-08-30 Yelena Mandelshtam

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

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

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 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

An open question in the theory of word-representable graphs for the past decade has been whether the line graph of a non-word-representable graph is always non-word-representable. By formulating an appropriate optimization problem for the…

Combinatorics · Mathematics 2021-08-06 M M Akbar , P D Akrobotu , C P Brewer

Jeff Remmel introduced the concept of a $k$-11-representable graph in 2017. This concept was first explored by Cheon et al. in 2019, who considered it as a natural extension of word-representable graphs, which are exactly 0-11-representable…

Combinatorics · Mathematics 2025-01-24 Mohammed Alshammari , Sergey Kitaev , Chaoliang Tang , Tianyi Tao , Junchi Zhang

The representation number of a graph is the minimum number of copies of each vertex required to represent the graph as a word, such that the letters corresponding to vertices $x$ and $y$ alternate if and only if $xy$ is an edge in the…

Combinatorics · Mathematics 2025-07-23 Nawaf Shafi Alshammari , Sergey Kitaev , Artem Pyatkin

This paper investigates the new notion of $2$-word-$\pi$-repre\-sentable graphs: the nodes of the graph correspond to the letters of the two words and there exists an edge between two nodes if the projections of any two letters of both…

Combinatorics · Mathematics 2026-05-27 Duncan Adamson , Amanita Dietz , Pamela Fleischmann , Annika Huch , Silas Cato Sacher

Recently, Jones et al. introduced the study of $u$-representable graphs, where $u$ is a word over $\{1,2\}$ containing at least one 1. The notion of a $u$-representable graph is a far-reaching generalization of the notion of a…

Combinatorics · Mathematics 2015-07-19 Sergey Kitaev

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

A 1-11-representation of a graph $G(V,E)$ is a word over the alphabet $V$ such that two distinct vertices $x$ and $y$ are adjacent if and only if the restricted word $w{x,y}$ (obtained from $w$ by deleting all letters except $x$ and $y$)…

Combinatorics · Mathematics 2026-01-29 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

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 this paper, we study the word-representability of well-partitioned chordal graphs using split decomposition. We show that every component of the minimal split decomposition of a well-partitioned chordal graph is a split graph. Thus we…

Combinatorics · Mathematics 2025-04-08 Tithi Dwary , K. V. Krishna

Word-representable graphs, which are the same as semi-transitively orientable graphs, generalize several fundamental classes of graphs. In this paper we propose a novel approach to study word-representability of graphs using a technique of…

Combinatorics · Mathematics 2023-12-19 Sumin Huang , Sergey Kitaev , Artem Pyatkin

A graph $G=(V,E)$ is called $(k,k')$-choosable if for any total list assignment $L$ which assigns to each vertex $v$ a set $L(v)$ of $k$ real numbers, and assigns to each edge $e$ a set $L(e)$ of $k'$ real numbers, there is a mapping…

Combinatorics · Mathematics 2024-03-05 T. Wu , J. Luo , Y. Gao

The graphs with permutation-representation number (\textit{prn}) at most two are known. While a characterization for the class of graphs with the \textit{prn} at most three is an open problem, we summarize the graphs of this class that are…

Discrete Mathematics · Computer Science 2023-10-03 Khyodeno Mozhui , K. V. Krishna

Several popular language models represent local contexts in an input text $x$ as bags of words. Such representations are naturally encoded by a sequence graph whose vertices are the distinct words occurring in $x$, with edges representing…

Data Structures and Algorithms · Computer Science 2025-07-14 Sammy Khalife , Yann Ponty , Laurent Bulteau