3 papers
math.CO2026
Linear clique-width and modular decomposition
Robert Brignall, Michal Opler, Vincent Vatter
A hereditary class of graphs has bounded clique-width if and only if its prime members do, but this lifting property fails for linear clique-width. We prove that a hereditary class…
math.CO2026
An assortment of problems in permutation patterns: unimodality, equivalence, derangements, and sorting
Vincent Vatter
We collect open problems in permutation patterns on four themes: rank-unimodality in the permutation pattern poset and log-convexity of principal classes, Wilf-equivalence and shap…
math.CO2021
Letter graphs and geometric grid classes of permutations
Bogdan Alecu, Robert Ferguson, Mamadou Moustapha Kanté +3
We uncover a connection between two seemingly unrelated notions: lettericity, from structural graph theory, and geometric griddability, from the world of permutation patterns. Both…