For large n we determine exactly the maximum numbers of induced C4 and C5 subgraphs that a planar graph on n vertices can contain. We show that K2,n−2 uniquely achieves this maximum in the C4 case, and we identify the graphs which achieve the maximum in the C5 case. This extends work in a paper by Hakimi and Schmeichel and a paper by Ghosh, Gy\H{o}ri, Janzer, Paulos, Salia, and Zamora which together determine both maxima asymptotically.
@article{arxiv.2108.00526,
title = {Planar graphs with the maximum number of induced 4-cycles or 5-cycles},
author = {Michael Savery},
journal= {arXiv preprint arXiv:2108.00526},
year = {2021}
}
Comments
v2: 30 pages and 6 figures, minor corrections and adjustments