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.
| Original language | English |
|---|---|
| Pages (from-to) | 293-333 |
| Number of pages | 41 |
| Journal | Journal of Combinatorial Theory. Series B |
| Volume | 97 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 2007 |
Keywords
- Forbidden subgraph
- Graph
- Model theory
- Tree
- Universal graph