English

Universal graphs with a forbidden subtree

Logic 2007-05-23 v1 Combinatorics

Abstract

We show that the problem of the existence of universal graphs with specified forbidden subgraphs can be systematically reduced to certain critical cases by a simple pruning technique which simplifies the underlying structure of the forbidden graphs, viewed as trees of blocks. As an application, we characterize the trees T for which a universal countable T-free graph exists.

Keywords

Cite

@article{arxiv.math/0512218,
  title  = {Universal graphs with a forbidden subtree},
  author = {Gregory Cherlin and Saharon Shelah},
  journal= {arXiv preprint arXiv:math/0512218},
  year   = {2007}
}