Title
Delta-Wye Transformations and the Efficient Reduction of Almost-Planar Graphs.
Abstract
A non-planar graph G is almost-planar if, for every edge e of G, either G\e or G/e is planar. We provide an algorithmic proof of a theorem by D. K. Wagner, according to which every almost-planar graph can be reduced to the graph K3,3 by some sequence of series/parallel reductions and delta-wye exchanges such that the reduction sequence is formed by almost-planar graphs. We study 3-connected almost-planar graphs on the projective plane and establish duality relations between the resulting families. We show that one family reduces to K3,3 (with an added parallel edge) while the dual family reduces to K5. We also characterize 3-terminal delta-wye reducibility for almost-planar graphs.
Year
DOI
Venue
2017
10.1016/j.endm.2017.10.023
Electronic Notes in Discrete Mathematics
Keywords
Field
DocType
delta-wye reducibility,almost-planar graphs,projective-planar graphs
Discrete mathematics,Outerplanar graph,Indifference graph,Combinatorics,Robertson–Seymour theorem,Forbidden graph characterization,Chordal graph,Pathwidth,1-planar graph,Mathematics,Planar graph
Journal
Volume
ISSN
Citations 
62
1571-0653
0
PageRank 
References 
Authors
0.34
2
2
Name
Order
Citations
PageRank
Isidoro Gitler1297.03
Gustavo Sandoval-Angeles200.34