A Note on Directed Genera of Some Tournaments
An embedding of a digraph in an orientable surface is an embedding as the underlying graph and arcs in each region force a directed cycle. The directed genus is the minimum genus of surfaces in which the digraph can be directed embedded. Bonnington, Conder, Morton and McKenna [J. Combin. Theory Ser....
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Published in | Acta Mathematicae Applicatae Sinica Vol. 34; no. 3; pp. 478 - 484 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
01.07.2018
Springer Nature B.V |
Edition | English series |
Subjects | |
Online Access | Get full text |
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Summary: | An embedding of a digraph in an orientable surface is an embedding as the underlying graph and arcs in each region force a directed cycle. The directed genus is the minimum genus of surfaces in which the digraph can be directed embedded. Bonnington, Conder, Morton and McKenna [J. Combin. Theory Ser. B, 85(2002) 1-20] gave the problem that which tournaments on
n
vertices have the directed genus ⌈(
n
−3)(
n
−4)/12 ⌉, the genus of
K
n
. In this paper, we use the current graph method to show that there exists a tournament, which has the directed genus ⌈(
n
−3)(
n
−4)/12 ⌉, on
n
vertices if and only if
n
≡ 3 or 7 (mod 12). |
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ISSN: | 0168-9673 1618-3932 |
DOI: | 10.1007/s10255-018-0763-9 |