English

Twin-width can be exponential in treewidth

Combinatorics 2022-04-19 v1 Discrete Mathematics

Abstract

For any small positive real ε\varepsilon and integer t>1εt > \frac{1}{\varepsilon}, we build a graph with a vertex deletion set of size tt to a tree, and twin-width greater than 2(1ε)t2^{(1-\varepsilon) t}. In particular, this shows that the twin-width is sometimes exponential in the treewidth, in the so-called oriented twin-width and grid number, and that adding an apex may multiply the twin-width by at least 2ε2-\varepsilon. Except for the one in oriented twin-width, these lower bounds are essentially tight.

Keywords

Cite

@article{arxiv.2204.07670,
  title  = {Twin-width can be exponential in treewidth},
  author = {Édouard Bonnet and Hugues Déprés},
  journal= {arXiv preprint arXiv:2204.07670},
  year   = {2022}
}

Comments

11 pages, 2 figures

R2 v1 2026-06-24T10:49:37.859Z