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In the first part of this paper, we consider weighted domination in the case where the vertices of the complete graph on~\(n\) vertices are equipped with independent and identically distributed (i.i.d.) weights. We use the probabilistic…

Probability · Mathematics 2023-01-16 Ghurumuruhan Ganesan

Consider the following random process: The vertices of a binomial random graph $G_{n,p}$ are revealed one by one, and at each step only the edges induced by the already revealed vertices are visible. Our goal is to assign to each vertex one…

Combinatorics · Mathematics 2018-02-16 Torsten Mütze , Thomas Rast , Reto Spöhel

We consider the problem of coloring graphs of maximum degree $\Delta$ with $\Delta$ colors in the distributed setting with limited bandwidth. Specifically, we give a $\mathsf{poly}\log\log n$-round randomized algorithm in the CONGEST model.…

Data Structures and Algorithms · Computer Science 2024-05-17 Yannic Maus , Magnús M. Halldórsson

In a bounded max-coloring of a vertex/edge weighted graph, each color class is of cardinality at most $b$ and of weight equal to the weight of the heaviest vertex/edge in this class. The bounded max-vertex/edge-coloring problems ask for…

Data Structures and Algorithms · Computer Science 2009-04-13 Evripidis Bampis , Alexander Kononov , Giorgio Lucarelli , Ioannis Milis

There are many variations on partition functions for graph homomorphisms or colorings. The case considered here is a counting or hard constraint problem in which the range or color graph carries a free and vertex transitive Abelian group…

Combinatorics · Mathematics 2012-04-06 Eric Babson , Matthias Beck

Motivated by his work on the classification of countable homogeneous oriented graphs, Cherlin asked about the typical structure of oriented graphs (i) without a transitive triangle, or (ii) without an oriented triangle. We give an answer to…

Combinatorics · Mathematics 2015-12-15 Deryk Osthus , Daniela Kühn , Timothy Townsend , Yi Zhao

For graphs $G$ and $H$, an $H$-coloring of $G$ is an edge-preserving mapping from $V(G)$ to $V(H)$. Note that if $H$ is the triangle, then $H$-colorings are equivalent to $3$-colorings. In this paper we are interested in the case that $H$…

Combinatorics · Mathematics 2026-03-23 Jan Goedgebeur , Jorik Jooken , Karolina Okrasa , Paweł Rzążewski , Oliver Schaudt

Hadwiger's conjecture, among the most famous open problems in graph theory, states that every graph that does not contain $K_t$ as a minor is properly $(t-1)$-colorable. The purpose of this work is to demonstrate that a natural extension of…

Combinatorics · Mathematics 2024-04-22 Raphael Steiner

We present an algorithm to count the number of occurrences of a pattern graph $H$ as an induced subgraph in a host graph $G$. If $G$ belongs to a bounded expansion class, the algorithm runs in linear time. Our design choices are motivated…

Data Structures and Algorithms · Computer Science 2020-01-16 Felix Reidl , Blair D. Sullivan

We consider the structure of $H$-free subgraphs of graphs with high minimal degree. We prove that for every $k>m$ there exists an $\epsilon:=\epsilon(k,m)>0$ so that the following holds. For every graph $H$ with chromatic number $k$ from…

Combinatorics · Mathematics 2017-06-20 Noga Alon , Clara Shikhelman

We study the maximization version of the fundamental graph coloring problem. Here the goal is to color the vertices of a k-colorable graph with k colors so that a maximum fraction of edges are properly colored (i.e. their endpoints receive…

Computational Complexity · Computer Science 2015-05-14 Venkatesan Guruswami , Ali Kemal Sinop

The local chromatic number of a graph G is the number of colors appearing in the most colorful closed neighborhood of a vertex minimized over all proper colorings of G. We show that two specific topological obstructions that have the same…

Combinatorics · Mathematics 2007-05-23 Gábor Simonyi , Gábor Tardos , Siniša T. Vrećica

This paper extends the scenario of the Four Color Theorem in the following way. Let H(d,k) be the set of all k-uniform hypergraphs that can be (linearly) embedded into R^d. We investigate lower and upper bounds on the maximum (weak and…

Combinatorics · Mathematics 2014-12-01 Carl Georg Heise , Konstantinos Panagiotou , Oleg Pikhurko , Anusch Taraz

Bousquet, Lochet and Thomass\'e recently gave an elegant proof that for any integer $n$, there is a least integer $f(n)$ such that any tournament whose arcs are coloured with $n$ colours contains a subset of vertices $S$ of size $f(n)$ with…

Combinatorics · Mathematics 2017-09-01 Laurent Beaudou , Luc Devroye , Gena Hahn

We prove several results on approximate decompositions of edge-coloured quasirandom graphs into rainbow spanning structures. More precisely, we say that an edge-colouring of a graph is locally $\ell$-bounded if no vertex is incident to more…

Combinatorics · Mathematics 2019-10-01 Jaehoon Kim , Daniela Kühn , Andrey Kupavskii , Deryk Osthus

Proper conflict-free coloring is an intermediate notion between proper coloring of a graph and proper coloring of its square. It is a proper coloring such that for every non-isolated vertex, there exists a color appearing exactly once in…

Combinatorics · Mathematics 2024-12-16 Chun-Hung Liu

One method to obtain a proper vertex coloring of graphs using a reasonable number of colors is to start from any arbitrary proper coloring and then repeat some local re-coloring techniques to reduce the number of color classes. The Grundy…

Discrete Mathematics · Computer Science 2024-03-05 Manouchehr Zaker

We study the online graph coloring problem restricted to the intersection graphs of intervals with lengths in $[1,\sigma]$. For $\sigma=1$ it is the class of unit interval graphs, and for $\sigma=\infty$ the class of all interval graphs.…

Given a class $\mathcal{H}$ of $m$ hypergraphs ${H}_1, {H}_2, \ldots, {H}_m$ with the same vertex set $V$, a cooperative coloring of them is a partition $\{I_1, I_2, \ldots, I_m\}$ of $V$ in such a way that each $I_i$ is an independent set…

Combinatorics · Mathematics 2024-08-08 Xuqing Bai , Bi Li , Weichan Liu , Xin Zhang

In this paper we study fractional coloring from the angle of distributed computing. Fractional coloring is the linear relaxation of the classical notion of coloring, and has many applications, in particular in scheduling. It was proved by…

Distributed, Parallel, and Cluster Computing · Computer Science 2021-03-15 Nicolas Bousquet , Louis Esperet , François Pirot