English

Structure and algorithms for graphs excluding grids with small parity breaks as odd-minors

Combinatorics 2024-10-03 v3 Discrete Mathematics

Abstract

We investigate a structural generalisation of treewidth we call A\mathcal{A}-blind-treewidth where A\mathcal{A} denotes an annotated graph class. This width parameter is defined by evaluating only the size of those bags BB of tree-decompositions for a graph GG where (G,B)A{(G,B) \notin \mathcal{A}}. For the two cases where A\mathcal{A} is (i) the class B\mathcal{B} of all pairs (G,X){(G,X)} such that no odd cycle in GG contains more than one vertex of XV(G){X \subseteq V(G)} and (ii) the class B\mathcal{B} together with the class P\mathcal{P} of all pairs (G,X){(G,X)} such that the "torso" of XX in GG is planar. For both classes, B\mathcal{B} and BP{\mathcal{B} \cup \mathcal{P}}, we obtain analogues of the Grid Theorem by Robertson and Seymour and FPT-algorithms that either compute decompositions of small width or correctly determine that the width of a given graph is large. Moreover, we present FPT-algorithms for Maximum Independent Set on graphs of bounded B\mathcal{B}-blind-treewidth and Maximum Cut on graphs of bounded (BP){(\mathcal{B}\cup\mathcal{P})}-blind-treewidth.

Keywords

Cite

@article{arxiv.2304.04504,
  title  = {Structure and algorithms for graphs excluding grids with small parity breaks as odd-minors},
  author = {J. Pascal Gollin and Sebastian Wiederrecht},
  journal= {arXiv preprint arXiv:2304.04504},
  year   = {2024}
}
R2 v1 2026-06-28T09:57:05.079Z