Choice numbers of graphs

dc.creatorGutner, Shai
dc.date2008-02-15
dc.date.accessioned2026-07-07T09:21:10Z
dc.date.available2026-07-07T09:21:10Z
dc.descriptionA solution to a problem of Erdős, Rubin and Taylor is obtained by showing that if a graph $G$ is $(a:b)$-choosable, and $c/d > a/b$, then $G$ is not necessarily $(c:d)$-choosable. The simplest case of another problem, stated by the same authors, is settled, proving that every 2-choosable graph is also $(4:2)$-choosable. Applying probabilistic methods, an upper bound for the $k^{th}$ choice number of a graph is given. We also prove that a directed graph with maximum outdegree $d$ and no odd directed cycle is $(k(d+1):k)$-choosable for every $k \geq 1$. Other results presented in this article are related to the strong choice number of graphs (a generalization of the strong chromatic number). We conclude with complexity analysis of some decision problems related to graph choosability.
dc.identifierhttps://arxiv.org/abs/0802.2157
dc.identifierhttp://arxiv.org/abs/0802.2157
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/154931
dc.subjectDiscrete Mathematics
dc.subjectComputational Complexity
dc.subjectData Structures and Algorithms
dc.titleChoice numbers of graphs
dc.typetext

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