The Erd\H{o}s-P\'osa property for infinite graphs
Abstract
We investigate which classes of infinite graphs have the Erd\H{o}s-P\'osa property (EPP). In addition to the usual EPP, we also consider the following infinite variant of the EPP: a class of graphs has the -EPP, where is an infinite cardinal, if for any graph there are either disjoint graphs from in or there is a set of vertices of of size less than such that contains no graph from . In particular, we study the (-)EPP for classes consisting of a single infinite graph . We obtain positive results when the set of induced subgraphs of is labelled well-quasi-ordered, and negative results when is not a proper subgraph of itself (both results require some additional conditions). As a corollary, we obtain that every graph which does not contain a path of length for some has the EPP and the -EPP. Furthermore, we show that the class of all subdivisions of any tree has the -EPP for every uncountable cardinal , and if is rayless, also the -EPP and the EPP.
Keywords
Cite
@article{arxiv.2411.02561,
title = {The Erd\H{o}s-P\'osa property for infinite graphs},
author = {Thilo Krill},
journal= {arXiv preprint arXiv:2411.02561},
year = {2024}
}
Comments
25 pages, 5 figures