기초과학연구원 이산수학그룹
We introduce and study a notion of decomposition of planar point sets (or rather of their chirotopes) as trees decorated by smaller chirotopes. This decomposition is based on the concept …
We will look at an analogue theorem of the classical Erdős-Pósa Theorem. We prove a $GF(q)$-representable matroid analogue of Robertson and Seymour's theorem that planar graphs have an Erdős-Pósa property. …
This talk deals with induced minor obstructions to treewidth. The natural setup for this problem is to consider the class of graphs excluding some planar graph, and some complete bipartite …
The grid theorem of Robertson and Seymour can be equivalently stated using balanced separators, that are separators whose deletion leaves every component with no more than half of the vertices …
I will introduce a new structure on finite graphs, which takes the form of a labeling of the vertices by nonnegative integers (possibly repeated). This labeling is isomorphism invariant, and …
For a set $X$ of integer points, the relaxation complexity $\operatorname{rc}(X)$ is the smallest number of facets of any polyhedron P whose integer points are precisely those of X. In …
A family of sets in $$ is called an $\ell$-Oddtown if the sizes of all sets are not divisible by $\ell$, but the sizes of pairwise intersections are divisible by …