13 citations · 54 across the 15 of their papers we have counts for
15 papers
Hedetniemi's conjecture and adjoint functors in thin categories
Jan Foniok, Claude Tardif
We survey results on Hedetniemi's conjecture which are connected to adjoint functors in the "thin" category of graphs, and expose the obstacles to extending these results.
Deciding the Bell number for hereditary graph properties
Aistis Atminas, Andrew Collins, Jan Foniok +1
The paper [J. Balogh, B. Bollobás, D. Weinreich, A jump to the Bell number for hereditary graph properties, J. Combin. Theory Ser. B 95 (2005) 29--48] identifies a jump in the spee…
Adjoint functors in graph theory
Jan Foniok, Claude Tardif
We survey some uses of adjoint functors in graph theory pertaining to colourings, complexity reductions, multiplicativity, circular colourings and tree duality. The exposition of t…
Digraph functors which admit both left and right adjoints
Jan Foniok, Claude Tardif
For our purposes, two functors Λ and Γ are said to be respectively left and right adjoints of each other if for any digraphs G and H, there exists a homomorphism of Λ(G) to H if an…
On Ramsey properties of classes with forbidden trees
Jan Foniok
Let F be a set of relational trees and let Forbh(F) be the class of all structures that admit no homomorphism from any tree in F; all this happens over a fixed finite relational si…
Ramsey Properties of Permutations
Julia Böttcher, Jan Foniok
The age of each countable homogeneous permutation forms a Ramsey class. Thus, there are five countably infinite Ramsey classes of permutations.