Raphael Steiner, Strengthening Hadwiger’s conjecture for 4- and 5-chromatic graphs
Room B332 IBS (기초과학연구원)Hadwiger's famous coloring conjecture states that every t-chromatic graph contains a
Hadwiger's famous coloring conjecture states that every t-chromatic graph contains a
A circle graph is an intersection graph of a set of chords of a circle. In this talk, I will describe the unavoidable induced subgraphs of circle graphs with large treewidth. This includes examples that are far from the `usual suspects'. Our results imply that treewidth and Hadwiger number are linearly tied on the class …
We show fixed-parameter tractability of the Directed Multicut problem with three terminal pairs (with a randomized algorithm). This problem, given a directed graph
Let
Let
Given an undirected planar graph
A subset
We give a summary on the work of the last months related to Frankl's Union-Closed conjecture and its offsprings. The initial conjecture is stated as a theorem in extremal set theory; when a family F is union-closed (the union of sets of F is itself a set of
In 1977, Erdős and Hajnal made the conjecture that, for every graph
Extremal Combinatorics studies the maximum or minimum size of finite objects (numbers, sets, graphs) satisfying certain properties. In this talk, I introduce the conjectures I solved on Extremal Combinatorics, and also introduce recent extremal problems.