English

$C_{2k}$-saturated graphs with no short odd cycles

Combinatorics 2018-10-16 v1

Abstract

The saturation number of a graph FF, written sat(n,F)\textup{sat}(n,F), is the minimum number of edges in an nn-vertex FF-saturated graph. One of the earliest results on saturation numbers is due to Erd\H{o}s, Hajnal, and Moon who determined sat(n,Kr)\textup{sat}(n,K_r) for all r3r \geq 3. Since then, saturation numbers of various graphs and hypergraphs have been studied. Motivated by Alon and Shikhelman's generalized Tur\'an function, Kritschgau et.\ al.\ defined sat(n,H,F)\textup{sat}(n,H,F) to be the minimum number of copies of HH in an nn-vertex FF-saturated graph. They proved, among other things, that sat(n,C3,C2k)=0\textup{sat}(n,C_3,C_{2k}) = 0 for all k3k \geq 3 and n2k+2n \geq 2k +2. We extend this result to all odd cycles by proving that for any odd integer r5r \geq 5, sat(n,Cr,C2k)=0\textup{sat}(n, C_r,C_{2k}) = 0 for all 2kr+52k \geq r+5 and n2krn \geq 2kr.

Keywords

Cite

@article{arxiv.1810.05772,
  title  = {$C_{2k}$-saturated graphs with no short odd cycles},
  author = {Craig Timmons},
  journal= {arXiv preprint arXiv:1810.05772},
  year   = {2018}
}
R2 v1 2026-06-23T04:38:20.046Z