2019. 10. 17. 14:15 - 2019. 10. 17. 15:45
MTA Rényi Alfréd Matematikai Kutatóitézet, Nagyterem
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Esemény típusa: szeminárium
Szervezés: Intézeti
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Kombinatorika szeminárium

Leírás

Gerbner Dániel: Generalized rainbow Turán problems

joint work with Tamás Mészáros, Abhishek Methuku and Cory Palmer

abstract:

Alon and Shikhelman initiated the systematic study of the following generalized Turán problem: for fixed graphs $H$ and $F$ and an integer $n$, what is the maximum number of copies of $H$, that can appear in an $n$-vertex $F$-free graph?

An edge-colored graph is called rainbow if all its edges have different colors. The rainbow Turán number of $F$ is defined as the maximum number of edges in a graph on $n$ vertices that has a proper edge-coloring with no rainbow copy of $F$. The study of rainbow Turán problems was initiated by Keevash, Mubayi, Sudakov and Verstra\"ete.

In this paper, we study the following natural generalization of these two problems: What is the maximum number of copies of $H$ in an $n$-vertex graph that has a proper edge-coloring without a rainbow copy of $F$? We focus on the case $H=F$ and establish new results for paths, cycles, trees and forests.