4 papers
Tight minimum degree conditions for apex-outerplanar minors and subdivisions in graphs and digraphs
Chun-Hung Liu, Youngho Yoo
Motivated by Hadwiger's conjecture and related problems for list-coloring, we study graphs for which every graph with minimum degree at least contains as a minor…
Homomorphism counting for immersion-closed classes is not isomorphism
Andrea Jiménez, Benjamin Moore, Daniel A. Quiroz +1
Lovász proved that two graphs and are isomorphic if for all graphs , where denotes the number of homomorphisms from to $G_…
ErdÅs-Pósa property of -paths in unoriented group-labelled graphs
O-joung Kwon, Youngho Yoo
We characterize the obstructions to the ErdÅs-Pósa property of -paths in unoriented group-labelled graphs. As a result, we prove that for every finite abelian group and f…
Tree-width of a graph excluding an apex-forest or a wheel as a minor
Chun-Hung Liu, Youngho Yoo
The Grid Minor Theorem states that for every planar graph , there exists a smallest integer such that every graph with tree-width at least contains as a minor.…