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Motivated by the definition of linear coloring on simplicial complexes, recently introduced in the context of algebraic topology \cite{Civan}, and the framework through which it was studied, we introduce the linear coloring on graphs. We…

Discrete Mathematics · Computer Science 2008-07-29 Kyriaki Ioannidou , Stavros D. Nikolopoulos

We present a new method for reducing the size of graphs with a given property. Our method, which is based on clausal proof minimization, allowed us to compute several 553-vertex unit-distance graphs with chromatic number 5, while the…

Combinatorics · Mathematics 2018-06-01 Marijn J. H. Heule

We prove that every cyclically 4-edge-connected cubic graph that can be embedded in the projective plane, with the single exception of the Petersen graph, is 3-edge-colorable. In other words, the only (non-trivial) snark that can be…

Combinatorics · Mathematics 2024-05-28 Yuta Inoue , Ken-ichi Kawarabayashi , Atsuyuki Miyashita , Bojan Mohar , Tomohiro Sonobe

An \emph{equitable coloring} of a graph is a proper vertex coloring such that the sizes of every two color classes differ by at most 1. Chen, Lih, and Wu conjectured that every connected graph $G$ with maximum degree $\Delta \geq 2$ has an…

Combinatorics · Mathematics 2012-03-05 Keaitsuda Nakprasit , Kittikorn Nakprasit

Say a graph $G$ is a {\em pentagraph} if every cycle has length at least five, and every induced cycle of odd length has length five. N. Robertson proposed the conjecture that the Petersen graph is the only pentagraph that is…

Combinatorics · Mathematics 2022-02-01 Maria Chudnovsky , Paul Seymour

An $acyclic$ edge coloring of a graph is a proper edge coloring such that there are no bichromatic cycles. The \emph{acyclic chromatic index} of a graph is the minimum number k such that there is an acyclic edge coloring using k colors and…

Discrete Mathematics · Computer Science 2009-08-18 Manu Basavaraju , L. Sunil Chandran

A hole is an induced cycle of length at least 4. A graph is called a pentagraph if it has no cycles of length 3 or 4 and has no holes of odd length at least 7, and is called a heptagraph if it has no cycles of length less than 7 and has no…

Combinatorics · Mathematics 2022-06-06 Wu Di , Baogang Xu , Yian Xu

We prove the existence of a function $f :\mathbb{N} \to \mathbb{N}$ such that the vertices of every planar graph with maximum degree $\Delta$ can be 3-colored in such a way that each monochromatic component has at most $f(\Delta)$ vertices.…

Combinatorics · Mathematics 2014-06-19 Louis Esperet , Gwenaël Joret

We present a simpler proof of a bound on the number of proper colorings of a graph that was obtained recently by Liu and Murty using Tur'an sieve (in fact, we prove a stronger inequality). We also point out that these results are subsumed…

Combinatorics · Mathematics 2007-05-23 Martin Klazar

Given a graph $G$, and a spanning subgraph $H$ of $G$, a circular $q$-backbone $k$-coloring of $(G,H)$ is a proper $k$-coloring $c$ of $G$ such that $q\le \lvert c(u)-c(v)\rvert \le k-q$, for every edge $uv\in E(H)$. The circular…

Discrete Mathematics · Computer Science 2016-04-21 Julio Araujo , Fabricio Benevides , Alexandre Cezar , Ana Silva

Consider a graph whose vertices are colored in one of two colors, say black or white. A white vertex is called integrated if it has at least as many black neighbors as white neighbors, and similarly for a black vertex. The coloring as a…

Combinatorics · Mathematics 2025-06-10 Charles Burnette , Broden Caton , Olivia Coward , Julian Davis , Austin Teter

DP-coloring is a generalization of list coloring that was introduced in 2015 by Dvo\v{r}\'{a}k and Postle. The chromatic polynomial of a graph is a notion that has been extensively studied since the early 20th century. The chromatic…

Combinatorics · Mathematics 2020-09-18 Jeffrey A. Mudrock , Seth Thomason

We prove that every cyclically 4-edge-connected cubic graph that can be embedded in the torus, with the exceptional graph class called "Petersen-like", is 3-edge-colorable. This means every (non-trivial) toroidal snark can be obtained from…

Combinatorics · Mathematics 2025-05-13 Yuta Inoue , Ken-ichi Kawarabayashi , Atsuyuki Miyashita , Bojan Mohar , Tomohiro Sonobe

We present a means of formulating and solving graph coloring problems with probabilistic graphical models. In contrast to the prevalent literature that uses factor graphs for this purpose, we instead approach it from a cluster graph…

Machine Learning · Computer Science 2021-10-06 Simon Streicher , Johan du Preez

A complete $k$-coloring of a graph $G=(V,E)$ is an assignment $\varphi:V\to\{1,\ldots,k\}$ of colors to the vertices such that no two vertices of the same color are adjacent, and the union of any two color classes contains at least one…

Discrete Mathematics · Computer Science 2013-12-31 Gabor Bacso , Piotr Borowiecki , Mihaly Hujter , Zsolt Tuza

We study the problem of online graph coloring for $k$-colorable graphs. The best previously known deterministic algorithm uses $\widetilde{O}(n^{1-\frac{1}{k!}})$ colors for general $k$ and $\widetilde{O}(n^{5/6})$ colors for $k = 4$, both…

Data Structures and Algorithms · Computer Science 2026-04-06 Ken-ichi Kawarabayashi , Hirotaka Yoneda , Masataka Yoneda

For a connected graph, we define the proper-walk connection number as the minimum number of colors needed to color the edges of a graph so that there is a walk between every pair of vertices without two consecutive edges having the same…

Combinatorics · Mathematics 2017-04-25 Robert Melville , Wayne Goddard

A strong $k$-edge-coloring of a graph $G$ is a mapping from $E(G)$ to $\{1,2,\ldots,k\}$ such that every pair of distinct edges at distance at most two receive different colors. The strong chromatic index $\chi'_s(G)$ of a graph $G$ is the…

Combinatorics · Mathematics 2015-09-28 Gerard Jennhwa Chang , Guan-Huei Duh

We consider cell colorings of drawings of graphs in the plane. Given a multi-graph $G$ together with a drawing $\Gamma(G)$ in the plane with only finitely many crossings, we define a cell $k$-coloring of $\Gamma(G)$ to be a coloring of the…

Combinatorics · Mathematics 2022-08-30 Christoph Hertrich , Felix Schröder , Raphael Steiner

We study the $\kappa$-color cyclic particle system on the one-dimensional integer lattice $\mathbb{Z}$, first introduced by Bramson and Griffeath in \cite{bramson1989flux}. In that paper they show that almost surely, every site changes its…

Probability · Mathematics 2018-04-18 Eric Foxall , Hanbaek Lyu
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