English

Packing and covering induced subdivisions

Discrete Mathematics 2018-11-13 v2

Abstract

A class F\mathcal{F} of graphs has the induced Erd\H{o}s-P\'osa property if there exists a function ff such that for every graph GG and every positive integer kk, GG contains either kk pairwise vertex-disjoint induced subgraphs that belong to F\mathcal{F}, or a vertex set of size at most f(k)f(k) hitting all induced copies of graphs in F\mathcal{F}. Kim and Kwon (SODA'18) showed that for a cycle CC_{\ell} of length \ell, the class of CC_{\ell}-subdivisions has the induced Erd\H{o}s-P\'osa property if and only if 4\ell\le 4. In this paper, we investigate whether or not the class of HH-subdivisions has the induced Erd\H{o}s-P\'osa property for other graphs HH. We completely settle the case when HH is a forest or a complete bipartite graph. Regarding the general case, we identify necessary conditions on HH for the class of HH-subdivisions to have the induced Erd\H{o}s-P\'osa property. For this, we provide three basic constructions that are useful to prove that the class of the subdivisions of a graph does not have the induced Erd\H{o}s-P\'osa property. Among remaining graphs, we prove that if HH is either the diamond, the 11-pan, or the 22-pan, then the class of HH-subdivisions has the induced Erd\H{o}s-P\'osa property.

Cite

@article{arxiv.1803.07581,
  title  = {Packing and covering induced subdivisions},
  author = {O-joung Kwon and Jean-Florent Raymond},
  journal= {arXiv preprint arXiv:1803.07581},
  year   = {2018}
}

Comments

39 pages

R2 v1 2026-06-23T00:59:19.684Z