English

Planar graphs with the maximum number of induced 4-cycles or 5-cycles

Combinatorics 2021-09-29 v2

Abstract

For large nn we determine exactly the maximum numbers of induced C4C_4 and C5C_5 subgraphs that a planar graph on nn vertices can contain. We show that K2,n2K_{2,n-2} uniquely achieves this maximum in the C4C_4 case, and we identify the graphs which achieve the maximum in the C5C_5 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.

Keywords

Cite

@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