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Hauptverfasser: Taranchuk, Vladislav, Timmons, Craig
Format: Preprint
Veröffentlicht: 2023
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Online-Zugang:https://arxiv.org/abs/2311.10379
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author Taranchuk, Vladislav
Timmons, Craig
author_facet Taranchuk, Vladislav
Timmons, Craig
contents A complete partition of a graph $G$ is a partition of the vertex set such that there is at least one edge between any two parts. The largest $r$ such that $G$ has a complete partition into $r$ parts, each of which is an independent set, is the achromatic number of $G$. We determine the achromatic number of polarity graphs of biaffine planes coming from generalized polygons. Our colorings of a family of unitary polarity graphs are used to solve a problem of Axenovich and Martin on complete partitions of $C_4$-free graphs. Furthermore, these colorings prove that there are sequences of graphs which are optimally complete and have unbounded degree, a problem that had been studied for the sequence of hypercubes independently by Roichman, and Ahlswede, Bezrukov, Blokhuis, Metsch, and Moorhouse.
format Preprint
id arxiv_https___arxiv_org_abs_2311_10379
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Achromatic colorings of polarity graphs
Taranchuk, Vladislav
Timmons, Craig
Combinatorics
A complete partition of a graph $G$ is a partition of the vertex set such that there is at least one edge between any two parts. The largest $r$ such that $G$ has a complete partition into $r$ parts, each of which is an independent set, is the achromatic number of $G$. We determine the achromatic number of polarity graphs of biaffine planes coming from generalized polygons. Our colorings of a family of unitary polarity graphs are used to solve a problem of Axenovich and Martin on complete partitions of $C_4$-free graphs. Furthermore, these colorings prove that there are sequences of graphs which are optimally complete and have unbounded degree, a problem that had been studied for the sequence of hypercubes independently by Roichman, and Ahlswede, Bezrukov, Blokhuis, Metsch, and Moorhouse.
title Achromatic colorings of polarity graphs
topic Combinatorics
url https://arxiv.org/abs/2311.10379