Improved Bounds for Some Facially Constrained Colorings

A facial-parity edge-coloring of a 2-edge-connected plane graph is a facially-proper edge-coloring in which every face is incident with zero or an odd number of edges of each color. A facial-parity vertex-coloring of a 2-connected plane graph is a proper vertex-coloring in which every face is incide...

Full description

Bibliographic Details
Main Author: Štorgel Kenny
Format: Article
Language:English
Published: University of Zielona Góra 2023-02-01
Series:Discussiones Mathematicae Graph Theory
Subjects:
Online Access:https://doi.org/10.7151/dmgt.2357
_version_ 1797705880209195008
author Štorgel Kenny
author_facet Štorgel Kenny
author_sort Štorgel Kenny
collection DOAJ
description A facial-parity edge-coloring of a 2-edge-connected plane graph is a facially-proper edge-coloring in which every face is incident with zero or an odd number of edges of each color. A facial-parity vertex-coloring of a 2-connected plane graph is a proper vertex-coloring in which every face is incident with zero or an odd number of vertices of each color. Czap and Jendroľ in [Facially-constrained colorings of plane graphs: A survey, Discrete Math. 340 (2017) 2691–2703], conjectured that 10 colors suffice in both colorings. We present an infinite family of counterexamples to both conjectures.
first_indexed 2024-03-12T05:43:51Z
format Article
id doaj.art-c9489242c1b44470a6ff959f56bff2d5
institution Directory Open Access Journal
issn 2083-5892
language English
last_indexed 2024-03-12T05:43:51Z
publishDate 2023-02-01
publisher University of Zielona Góra
record_format Article
series Discussiones Mathematicae Graph Theory
spelling doaj.art-c9489242c1b44470a6ff959f56bff2d52023-09-03T05:51:42ZengUniversity of Zielona GóraDiscussiones Mathematicae Graph Theory2083-58922023-02-0143115115810.7151/dmgt.2357Improved Bounds for Some Facially Constrained ColoringsŠtorgel Kenny0Faculty of Information Studies, Novo mesto, Slovenia University of Primorska, FAMNIT, Koper, SloveniaA facial-parity edge-coloring of a 2-edge-connected plane graph is a facially-proper edge-coloring in which every face is incident with zero or an odd number of edges of each color. A facial-parity vertex-coloring of a 2-connected plane graph is a proper vertex-coloring in which every face is incident with zero or an odd number of vertices of each color. Czap and Jendroľ in [Facially-constrained colorings of plane graphs: A survey, Discrete Math. 340 (2017) 2691–2703], conjectured that 10 colors suffice in both colorings. We present an infinite family of counterexamples to both conjectures.https://doi.org/10.7151/dmgt.2357plane graphfacial coloringfacial-parity edge-coloringfacial-parity vertex-coloringworm coloring05c1505c10
spellingShingle Štorgel Kenny
Improved Bounds for Some Facially Constrained Colorings
Discussiones Mathematicae Graph Theory
plane graph
facial coloring
facial-parity edge-coloring
facial-parity vertex-coloring
worm coloring
05c15
05c10
title Improved Bounds for Some Facially Constrained Colorings
title_full Improved Bounds for Some Facially Constrained Colorings
title_fullStr Improved Bounds for Some Facially Constrained Colorings
title_full_unstemmed Improved Bounds for Some Facially Constrained Colorings
title_short Improved Bounds for Some Facially Constrained Colorings
title_sort improved bounds for some facially constrained colorings
topic plane graph
facial coloring
facial-parity edge-coloring
facial-parity vertex-coloring
worm coloring
05c15
05c10
url https://doi.org/10.7151/dmgt.2357
work_keys_str_mv AT storgelkenny improvedboundsforsomefaciallyconstrainedcolorings