Predavateljica: Eva Czabarka (University of South Carolina, ZDA)

The minimum number of crossings a plane drawing of a graph must have is its crossing number. Crossing numbers were introduced by Turan and they turned relevant for VLSI designs in the computer age. The crossing lemma has many surprising applications in several areas of mathematics. There are many analogues of crossing numbers; I will speak is about biplanar crossing number and minor crossing number of graphs. The talk will investigate how these numbers compare with the (ordinary) crossing number.