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Related papers: Fractional Zero Forcing via Three-color Forcing Ga…

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In 2018, forts were defined as non-empty subsets of vertices in a graph where no vertex outside the set has exactly one neighbor in the set. Forts have since been used to characterize zero forcing sets, model zero forcing as an integer…

Combinatorics · Mathematics 2025-07-16 Boris Brimkov , Thomas R. Cameron , Owen Grubbs

In a fractional coloring, vertices of a graph are assigned measurable subsets of the real line and adjacent vertices receive disjoint subsets; the fractional chromatic number of a graph is at most $k$ if it has a fractional coloring in…

Combinatorics · Mathematics 2024-07-25 Tom Kelly , Luke Postle

The semi-random graph process is a single player game in which the player is initially presented an empty graph on $n$ vertices. In each round, a vertex $u$ is presented to the player independently and uniformly at random. The player then…

Combinatorics · Mathematics 2022-02-21 Pu Gao , Calum MacRury , Pawel Pralat

Zero forcing is a graph coloring process that was defined as a tool for bounding the minimum rank and maximum nullity of a graph. It has also been used for studying control of quantum systems and monitoring electrical power networks. One of…

Combinatorics · Mathematics 2020-05-18 P. A. CrowdMath

A graph G is (a:b)-colorable if there exists an assignment of b-element subsets of {1,...,a} to vertices of G such that sets assigned to adjacent vertices are disjoint. We first show that for every triangle-free planar graph G and a vertex…

Combinatorics · Mathematics 2018-09-17 Zdeněk Dvořák , Xiaolan Hu

We give a randomized algorithm that properly colors the vertices of a triangle-free graph G on n vertices using O(\Delta(G)/ log \Delta(G)) colors, where \Delta(G) is the maximum degree of G. The algorithm takes O(n\Delta2(G)log\Delta(G))…

Combinatorics · Mathematics 2011-02-01 Mohammad Shoaib Jamall

This paper begins the study of reconfiguration of zero forcing sets, and more specifically, the zero forcing graph. Given a base graph $G$, its zero forcing graph, $\mathscr{Z}(G)$, is the graph whose vertices are the minimum zero forcing…

Combinatorics · Mathematics 2020-09-02 Jesse Geneson , Ruth Haas , Leslie Hogben

Motivated in part by an observation that the zero forcing number for the complement of a tree on $n$ vertices is either $n-3$ or $n-1$ in one exceptional case, we consider the zero forcing number for the complement of more general graphs…

Combinatorics · Mathematics 2023-03-13 Emelie Curl , Shaun Fallat , Ryan Moruzzi , Carolyn Reinhart , Derek Young

Consider a coloring of a graph such that each vertex is assigned a fraction of each color, with the total amount of colors at each vertex summing to $1$. We define the fractional defect of a vertex $v$ to be the sum of the overlaps with…

Combinatorics · Mathematics 2019-11-11 Wayne Goddard , Honghai Xu

We give a linear-time algorithm to decide 3-colorability of a triangle-free graph embedded in a fixed surface, and a quadratic-time algorithm to output a 3-coloring in the affirmative case. The algorithms also allow to prescribe the…

Discrete Mathematics · Computer Science 2020-11-10 Zdenek Dvorak , Daniel Kral , Robin Thomas

A graph drawn in a surface is a near-quadrangulation if the sum of the lengths of the faces different from 4-faces is bounded by a fixed constant. We leverage duality between colorings and flows to design an efficient algorithm for…

Combinatorics · Mathematics 2023-03-13 Caroline Bang , Zdeněk Dvořák , Emily Heath , Bernard Lidický

Let $G$ be a simple, finite graph with vertex set $V(G)$ and edge set $E(G)$, where each vertex is either colored blue or white. Define the standard zero forcing process on $G$ with the following color-change rule: let $S$ be the set of all…

Combinatorics · Mathematics 2022-02-11 Ma. Nerissa M. Abara , Prince Allan B. Pelayo

The fractional and circular chromatic numbers are the two most studied non-integral refinements of the chromatic number of a graph. Starting from the definition of a coloring base of a graph, which originated in work related to ergodic…

Combinatorics · Mathematics 2021-01-12 Pablo Candela , Carlos Catala , Robert Hancock , Adam Kabela , Daniel Kral , Ander Lamaison , Lluis Vena

We show a method how to convert any graph into the binary number and vice versa. We derive upper bound for maximum number of graphs, that, have fixed number of vertices and can be colored with n colors (n is any given number). Proof for the…

Combinatorics · Mathematics 2007-05-23 Kamil Kulesza , Zbigniew Kotulski

We define the $d$-defective incidence chromatic number of a graph, generalizing the notion of incidence chromatic number, and determine it for some classes of graphs including trees, complete bipartite graphs, complete graphs, and…

Combinatorics · Mathematics 2022-02-09 Huimin Bi , Xin Zhang

We prove that every planar triangle-free graph on $n$ vertices has fractional chromatic number at most $3-\frac{1}{n+1/3}$.

Combinatorics · Mathematics 2014-02-24 Zdeněk Dvořák , Jean-Sébastien Sereni , Jan Volec

In this paper, we initiate the study of the vertex coloring problem of a graph in the semi streaming model. In this model, the input graph is defined by a stream of edges, arriving in adversarial order and any algorithm must process the…

Data Structures and Algorithms · Computer Science 2018-07-26 Suman Kalyan Bera , Prantar Ghosh

Hopping forcing is a single player combinatorial game in which the player is presented a graph on $n$ vertices, some of which are initially blue with the remaining vertices being white. In each round $t$, a blue vertex $v$ with all…

Combinatorics · Mathematics 2024-10-14 Pawel Pralat , Harjas Singh

In communication networks, the binding numbers of graphs (or networks) are often used to measure the vulnerability and robustness of graphs (or networks). Furthermore, the fractional factors of graphs and the fractional…

Combinatorics · Mathematics 2023-06-22 Sizhong Zhou

Many problems can be presented in an abstract form through a wide range of binary objects and relations which are defined over problem domain. In these problems, graphical demonstration of defined binary objects and solutions is the most…

Graphics · Computer Science 2016-03-24 Mohammadreza Ashouri , Ali Golshani , Dara Moazzmi , Mandana Ghasemi
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