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On dihedral flows in embedded graphs

Let [Formula: see text] be a multigraph with for each vertex a cyclic order of the edges incident with it. For [Formula: see text] , let [Formula: see text] be the dihedral group of order [Formula: see text]. Define [Formula: see text]. Goodall et al in 2016 asked whether [Formula: see text] admits...

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Detalles Bibliográficos
Autor principal: Litjens, Bart
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6559332/
https://www.ncbi.nlm.nih.gov/pubmed/31217666
http://dx.doi.org/10.1002/jgt.22427
Descripción
Sumario:Let [Formula: see text] be a multigraph with for each vertex a cyclic order of the edges incident with it. For [Formula: see text] , let [Formula: see text] be the dihedral group of order [Formula: see text]. Define [Formula: see text]. Goodall et al in 2016 asked whether [Formula: see text] admits a nowhere‐identity [Formula: see text] ‐flow if and only if it admits a nowhere‐identity [Formula: see text] ‐flow with [Formula: see text] (a “nowhere‐identity dihedral [Formula: see text] ‐flow”). We give counterexamples to this statement and provide general obstructions. Furthermore, the complexity of deciding the existence of nowhere‐identity [Formula: see text] ‐flows is discussed. Lastly, graphs in which the equivalence of the existence of flows as above is true are described. We focus particularly on cubic graphs.