Linear Operators That Preserve the Genus of a Graph

Autor: LeRoy B. Beasley, Jeong Han Kim, Seok-Zun Song
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Mathematics, Vol 7, Iss 4, p 312 (2019)
Druh dokumentu: article
ISSN: 2227-7390
DOI: 10.3390/math7040312
Popis: A graph has genus k if it can be embedded without edge crossings on a smooth orientable surface of genus k and not on one of genus k − 1 . A mapping of the set of graphs on n vertices to itself is called a linear operator if the image of a union of graphs is the union of their images and if it maps the edgeless graph to the edgeless graph. We investigate linear operators on the set of graphs on n vertices that map graphs of genus k to graphs of genus k and graphs of genus k + 1 to graphs of genus k + 1 . We show that such linear operators are necessarily vertex permutations. Similar results with different restrictions on the genus k preserving operators give the same conclusion.
Databáze: Directory of Open Access Journals
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