Paul Seymour, Polynomial bounds for chromatic number
Zoom ID: 869 4632 6610 (ibsdimag)The Gyárfás-Sumner conjecture says that for every forest
The Gyárfás-Sumner conjecture says that for every forest
Majority dynamics on a graph
Bouchet (1987) defined delta-matroids by relaxing the base exchange axiom of matroids. Oum (2009) introduced a graphic delta-matroid from a pair of a graph and its vertex subset. We define …
A family
The independence number of a tree decomposition
A well-known theorem of Whitney states that a 3-connected planar graph admits an essentially unique embedding into the 2-sphere. We prove a 3-dimensional analogue: a simply-connected 2-complex every link graph …
Matching minors are a specialisation of minors which preserves the existence and elementary structural properties of perfect matchings. They were first discovered as part of the study of the Pfaffian …
The poset Ramsey number
Branchwidth determines how graphs, and more generally, arbitrary connectivity (basically symmetric and submodular) functions could be decomposed into a tree-like structure by specific cuts. We develop a general framework for …
What is the largest number