Planar graphs with the maximum number of induced 6-cycles
Combinatorics
2024-01-23 v2
Abstract
For large we determine the maximum number of induced 6-cycles which can be contained in a planar graph on vertices, and we classify the graphs which achieve this maximum. In particular we show that the maximum is achieved by the graph obtained by blowing up three pairwise non-adjacent vertices in a 6-cycle to sets of as even size as possible, and that every extremal example closely resembles this graph. This extends previous work by the author which solves the problem for 4-cycles and 5-cycles. The 5-cycle problem was also solved independently by Ghosh, Gy\H{o}ri, Janzer, Paulos, Salia, and Zamora.
Cite
@article{arxiv.2110.07319,
title = {Planar graphs with the maximum number of induced 6-cycles},
author = {Michael Savery},
journal= {arXiv preprint arXiv:2110.07319},
year = {2024}
}
Comments
23 pages, 4 figures; final version; v2: small changes incorporating referee's comments