English

Orthogonal polarity graphs and Sidon sets

Combinatorics 2014-08-12 v3

Abstract

Determining the maximum number of edges in an nn-vertex C4C_4-free graph is a well-studied problem that dates back to a paper of Erd\H{o}s from 1938. One of the most important families of C4C_4-free graphs are the Erd\H{o}s-R\'enyi orthogonal polarity graphs. We show that the Cayley sum graph constructed using a Bose-Chowla Sidon set is isomorphic to a large induced subgraph of the Erd\H{o}s-R\'enyi orthogonal polarity graph. Using this isomorphism we prove that the Petersen graph is a subgraph of every sufficiently large Erd\H{o}s-R\'enyi orthogonal polarity graph.

Keywords

Cite

@article{arxiv.1403.4489,
  title  = {Orthogonal polarity graphs and Sidon sets},
  author = {Michael Tait and Craig Timmons},
  journal= {arXiv preprint arXiv:1403.4489},
  year   = {2014}
}

Comments

The authors would like to thank Jason Williford for noticing an error in the proof of Theorem 1.2 in the previous version. This error has now been corrected

R2 v1 2026-06-22T03:29:08.989Z