Maximum Matchings and Minimum Blocking Sets in \varTheta _6 -Graphs

Therese Biedl, Ahmad Biniaz, Veronika Irvine, Kshitij Jain, Philipp Kindermann, Anna Lubiw

Abstract: varTheta _6\)-graphs are important geometric graphs that have many applications especially in wireless sensor networks. They are equivalent to Delaunay graphs where empty equilateral triangles take the place of empty circles. We investigate lower bounds on the size of maximum matchings in these graphs. The best known lower bound is n/3, where n is the number of vertices of the graph, which comes from half-\(\varTheta _6\)-graphs that are subgraphs of \(\varTheta _6\)-graphs. Babu et al. (2014) conjectured that any \(\varTheta _6\)-graph has a (near-)perfect matching (as is true for standard Delaunay graphs). Although this conjecture remains open, we improve the lower bound to \((3n-8)/7\).