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Related papers: Some results on total weight choosability

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A graph $G$ is {\em $k$-choosable} if for every assignment of a set $S(v)$ of $k$ colors to every vertex $v$ of $G$, there is a proper coloring of $G$ that assigns to each vertex $v$ a color from $S(v)$. We consider the complexity of…

Discrete Mathematics · Computer Science 2008-02-20 Shai Gutner

Given positive integers $k \leq m$ and a graph $G$, a family of lists $L = \{L(v) : v \in V(G)\}$ is said to be a random $(k,m)$-list-assignment if for every $v \in V(G)$ the list $L(v)$ is a subset of $\{1, \ldots, m\}$ of size $k$, chosen…

Combinatorics · Mathematics 2024-04-10 Dan Hefetz , Michael Krivelevich

For a hypergraph G and a positive integer s, let \chi_{\ell} (G,s) be the minimum value of l such that G is L-colorable from every list L with |L(v)|=l for each v\in V(G) and |L(u)\cap L(v)|\leq s for all u, v\in e\in E(G). This parameter…

Combinatorics · Mathematics 2011-09-15 Zoltán Füredi , Alexandr Kostochka , Mohit Kumbhat

Proportional choosability is a list coloring analogue of equitable coloring. Specifically, a $k$-assignment $L$ for a graph $G$ specifies a list $L(v)$ of $k$ available colors to each $v \in V(G)$. An $L$-coloring assigns a color to each…

Combinatorics · Mathematics 2020-06-04 Jeffrey A. Mudrock , Robert Piechota , Paul Shin , Tim Wagstrom

A proper vertex coloring of a graph is equitable if the sizes of all color classes differ by at most $1$. For a list assignment $L$ of $k$ colors to each vertex of an $n$-vertex graph $G$, an equitable $L$-coloring of $G$ is a proper…

Combinatorics · Mathematics 2025-12-30 H. A. Kierstead , Alexandr Kostochka , Zimu Xiang

List coloring generalizes graph coloring by requiring the color of a vertex to be selected from a list of colors specific to that vertex. One refinement of list coloring, called choosability with separation, requires that the intersection…

Combinatorics · Mathematics 2015-12-25 Mohit Kumbhat , Kevin Moss , Derrick Stolee

A graph $G$ is called \emph{chromatic-choosable} if its choice number is equal to its chromatic number, namely $Ch(G)=\chi(G)$. Ohba has conjectured that every graph $G$ satisfying $|V(G)|\leq 2\chi(G)+1$ is chromatic-choosable. Since each…

Combinatorics · Mathematics 2015-08-06 Wenjie He , Lingmin Zhang , Daniel W. Cranston , Yufa Shen , Guoping Zheng

A graph $G$ is called $3$-choice critical if $G$ is not $2$-choosable but any proper subgraph is $2$-choosable. A characterization of $3$-choice critical graphs was given by Voigt in [On list Colourings and Choosability of Graphs,…

Combinatorics · Mathematics 2020-06-30 Rongxing Xu , Xuding Zhu

Let G=(V,E) be a graph and let f be a function that assigns list sizes to the vertices of G. It is said that G is f-choosable if for every assignment of lists of colors to the vertices of G for which the list sizes agree with f, there…

Combinatorics · Mathematics 2013-05-10 Michelle Lastrina , Michael Young

A $k$-uniform hypergraph (or $k$-graph) $H = (V, E)$ is $k$-partite if $V$ can be partitioned into $k$ sets $V_1, \ldots, V_k$ such that each edge in $E$ contains precisely one vertex from each $V_i$. We show that $k$-partite $k$-graphs of…

Combinatorics · Mathematics 2025-12-25 Peter Bradshaw , Abhishek Dhawan , Nhi Dinh , Shlok Mulye , Rohan Rathi

A graph $G$ is free $(a,b)$-choosable if for any vertex $v$ with $b$ colors assigned and for any list of colors of size $a$ associated with each vertex $u\ne v$, the coloring can be completed by choosing for $u$ a subset of $b$ colors such…

Combinatorics · Mathematics 2014-03-11 Yves Aubry , Jean-Christophe Godin , Olivier Togni

A colouring of a graph $G=(V,E)$ is a function $c: V\rightarrow\{1,2,\ldots \}$ such that $c(u)\neq c(v)$ for every $uv\in E$. A $k$-regular list assignment of $G$ is a function $L$ with domain $V$ such that for every $u\in V$, $L(u)$ is a…

Data Structures and Algorithms · Computer Science 2019-02-08 Konrad K. Dabrowski , Francois Dross , Matthew Johnson , Daniel Paulusma

A graph $G$ is $(a,b)$-choosable if for any color list of size $a$ associated with each vertices, one can choose a subset of $b$ colors such that adjacent vertices are colored with disjoint color sets. This paper shows an equivalence…

Discrete Mathematics · Computer Science 2010-06-16 Yves Aubry , Godin Jean-Christophe , Togni Olivier

An $(L,d)^*$-coloring is a mapping $\phi$ that assigns a color $\phi(v)\in L(v)$ to each vertex $v\in V(G)$ such that at most $d$ neighbors of $v$ receive colore $\phi(v)$. A graph is called $(m,d)^*$-choosable, if $G$ admits an…

Combinatorics · Mathematics 2007-05-23 Baogang Xu , Qinglin Yu

A graph $G$ is list point $k$-arborable if, whenever we are given a $k$-list assignment $L(v)$ of colors for each vertex $v\in V(G)$, we can choose a color $c(v)\in L(v)$ for each vertex $v$ so that each color class induces an acyclic…

Combinatorics · Mathematics 2014-03-13 Xin Zhang

A graph $G$ is called chromatic-choosable if $\chi(G)=ch(G)$. A natural problem is to determine the minimum number of vertices in a $k$-chromatic non-$k$-choosable graph. It was conjectured by Ohba, and proved by Noel, Reed and Wu that…

Combinatorics · Mathematics 2025-01-01 Jialu Zhu , Xuding Zhu

A graph $G$ is said to be $k$-subspace choosable over a field $\mathbb{F}$ if for every assignment of $k$-dimensional subspaces of some finite-dimensional vector space over $\mathbb{F}$ to the vertices of $G$, it is possible to choose for…

Combinatorics · Mathematics 2022-04-13 Dror Chawin , Ishay Haviv

A graph G is k-choosable if G can be properly colored whenever every vertex has a list of at least k available colors. Thomassen's theorem states that every planar graph is 5-choosable. We extend the result by showing that every graph with…

Combinatorics · Mathematics 2018-10-26 Zdeněk Dvořák , Bernard Lidický , Riste Škrekovski

A graph is $\ell$-choosable if, for any choice of lists of $\ell$ colors for each vertex, there is a list coloring, which is a coloring where each vertex receives a color from its list. We study complexity issues of choosability of graphs…

Discrete Mathematics · Computer Science 2017-08-14 Marc Demange , Dominique de Werra

All planar graphs are 4-colorable and 5-choosable, while some planar graphs are not 4-choosable. Determining which properties guarantee that a planar graph can be colored using lists of size four has received significant attention. In terms…