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
Description
Summary: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.
ISSN:2083-5892