Coloring minimal Cayley graphs.

In 1978 Babai raised the question whether all minimal Cayley graphs have bounded chromatic number; in 1994 he conjectured a negative answer. In this paper we show that any minimal Cayley graph of a (finitely generated) generalized dihedral or nilpotent group has chromatic number at most 3, while 4 c...

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Authors: García Marco, Ignacio; Knauer, Kolja
Format: Article
Status:Published version
Publication date:2025
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/224639
Online Access:https://hdl.handle.net/2445/224639
Access Level:Open access
Keyword:Teoria de grafs
Geometria combinatòria
Graph theory
Combinatorial geometry
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author García Marco, Ignacio
author2 Knauer, Kolja
author2_role author
author_browse García Marco, Ignacio
Knauer, Kolja
author_facet García Marco, Ignacio
Knauer, Kolja
author_role author
collection Recercat. Dipósit de la Recerca de Catalunya
description In 1978 Babai raised the question whether all minimal Cayley graphs have bounded chromatic number; in 1994 he conjectured a negative answer. In this paper we show that any minimal Cayley graph of a (finitely generated) generalized dihedral or nilpotent group has chromatic number at most 3, while 4 colors are sometimes necessary for soluble groups. On the other hand we address a related question proposed by Babai in 1978 by constructing graphs of unbounded chromatic number that admit a proper edge coloring such that each cycle has some color at least twice. The latter can be viewed as a step towards confirming Babai’s 1994 conjecture – a problem that remains open.
eu_rights_str_mv openAccess
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institution Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
instname_str Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
network_acronym_str ES
network_name_str España
oai_identifier_str oai:recercat.cat:2445/224639
publishDate 2025
publishDateSort 2025
publisher Elsevier Ltd.
publisherStr Elsevier Ltd.
reponame_str Recercat. Dipósit de la Recerca de Catalunya
spelling Coloring minimal Cayley graphs. García Marco, Ignacio Knauer, Kolja Teoria de grafs Geometria combinatòria Graph theory Combinatorial geometry In 1978 Babai raised the question whether all minimal Cayley graphs have bounded chromatic number; in 1994 he conjectured a negative answer. In this paper we show that any minimal Cayley graph of a (finitely generated) generalized dihedral or nilpotent group has chromatic number at most 3, while 4 colors are sometimes necessary for soluble groups. On the other hand we address a related question proposed by Babai in 1978 by constructing graphs of unbounded chromatic number that admit a proper edge coloring such that each cycle has some color at least twice. The latter can be viewed as a step towards confirming Babai’s 1994 conjecture – a problem that remains open. Elsevier Ltd. https://hdl.handle.net/2445/224639
spellingShingle Coloring minimal Cayley graphs.
García Marco, Ignacio
Teoria de grafs
Geometria combinatòria
Graph theory
Combinatorial geometry
status_str publishedVersion
title Coloring minimal Cayley graphs.
title_full Coloring minimal Cayley graphs.
title_fullStr Coloring minimal Cayley graphs.
title_full_unstemmed Coloring minimal Cayley graphs.
title_short Coloring minimal Cayley graphs.
title_sort Coloring minimal Cayley graphs.
topic Teoria de grafs
Geometria combinatòria
Graph theory
Combinatorial geometry
topic_facet Teoria de grafs
Geometria combinatòria
Graph theory
Combinatorial geometry
url https://hdl.handle.net/2445/224639