English

Shrub-depth: Capturing Height of Dense Graphs

Logic in Computer Science 2023-06-22 v4 Discrete Mathematics Combinatorics

Abstract

The recent increase of interest in the graph invariant called tree-depth and in its applications in algorithms and logic on graphs led to a natural question: is there an analogously useful "depth" notion also for dense graphs (say; one which is stable under graph complementation)? To this end, in a 2012 conference paper, a new notion of shrub-depth has been introduced, such that it is related to the established notion of clique-width in a similar way as tree-depth is related to tree-width. Since then shrub-depth has been successfully used in several research papers. Here we provide an in-depth review of the definition and basic properties of shrub-depth, and we focus on its logical aspects which turned out to be most useful. In particular, we use shrub-depth to give a characterization of the lower ω{\omega} levels of the MSO1 transduction hierarchy of simple graphs.

Keywords

Cite

@article{arxiv.1707.00359,
  title  = {Shrub-depth: Capturing Height of Dense Graphs},
  author = {Robert Ganian and Petr Hliněný and Jaroslav Nešetřil and Jan Obdržálek and Patrice Ossona de Mendez},
  journal= {arXiv preprint arXiv:1707.00359},
  year   = {2023}
}
R2 v1 2026-06-22T20:35:44.934Z