Finding Large Matchings in 1-Planar Graphs of Minimum Degree 3

Abstract

A matching is a set of edges without common endpoint. It was recently shown that every 1-planar graph (i.e., a graph that can be drawn in the plane with at most one crossing per edge) that has minimum degree 3 has a matching of size at least n+127 , and this is tight for some graphs. The proof did not come with an algorithm to find the matching more efficiently than a general-purpose maximum-matching algorithm. In this paper, we give such an algorithm. More generally, we show that any matching that has no augmenting paths of length 9 or less has size at least n+127 in a 1-planar graph with minimum degree 3. F. Klute—This work was conducted while FK was a member of the “Algorithms and Complexity Group” at TU Wien. Research of TB supported by NSERC. Research initiated while FK was visiting the University of Waterloo.