,
Prosenjit Bose
,
Aaron Büngener,
Vida Dujmović
,
Michael Hoffmann
,
Michael Kaufmann
,
Pat Morin
,
Saeed Odak,
Alexandra Weinberger
Creative Commons Attribution 4.0 International license
We study the impact of forbidding short cycles to the edge density of k-planar graphs; a k-planar graph is one that can be drawn in the plane with at most k crossings per edge. Specifically, we consider three settings, according to which the forbidden substructures are 3-cycles, 4-cycles or both of them (i.e., girth ≥ 5). For all three settings and all k ∈ {1,2,3}, we present lower and upper bounds on the maximum number of edges in any k-planar graph on n vertices. Our bounds are of the form c n, for some explicit constant c that depends on k and on the setting. For general k ≥ 4 our bounds are of the form c√kn, for some explicit constant c. These results are obtained by leveraging different techniques, such as the discharging method, the recently introduced density formula for non-planar graphs, and new upper bounds for the crossing number of 2- and 3-planar graphs in combination with corresponding lower bounds based on the Crossing Lemma.
@InProceedings{bekos_et_al:LIPIcs.GD.2024.27,
author = {Bekos, Michael A. and Bose, Prosenjit and B\"{u}ngener, Aaron and Dujmovi\'{c}, Vida and Hoffmann, Michael and Kaufmann, Michael and Morin, Pat and Odak, Saeed and Weinberger, Alexandra},
title = {{On k-Planar Graphs Without Short Cycles}},
booktitle = {32nd International Symposium on Graph Drawing and Network Visualization (GD 2024)},
pages = {27:1--27:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-343-0},
ISSN = {1868-8969},
year = {2024},
volume = {320},
editor = {Felsner, Stefan and Klein, Karsten},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.GD.2024.27},
URN = {urn:nbn:de:0030-drops-213117},
doi = {10.4230/LIPIcs.GD.2024.27},
annote = {Keywords: Beyond-planar Graphs, k-planar Graphs, Local Crossing Number, Crossing Number, Discharging Method, Crossing Lemma}
}