Size-Ramsey numbers of powers of hypergraph trees and long subdivisions

Speaker: Liana Yepremyan

Date: Thu, Mar 11, 2021

Location: Zoom, PIMS, University of Victoria

Conference: PIMS-UVic Discrete Math Seminar

Subject: Mathematics

Class: Scientific

Abstract:

The s-colour size-Ramsey number of a hypergraph H is the minimum number of edges in a hypergraph G whose every s-edge-colouring contains a monochromatic copy of H. We show that the s-colour size-Ramsey number of the t-power of the r-uniform tight path on n vertices is linear in n, for every fixed r,s,t, thus answering a question of Dudek, La Fleur, Mubayi, and R\"odl (2017). In fact, we prove a stronger result that allows us to deduce that powers of bounded degree hypergraph trees and of `long subdivisions' of bounded degree hypergraphs have size-Ramsey numbers that are linear in the number of vertices. This extends recent results about the linearity of size-Ramsey numbers of powers of bounded degree trees and of long subdivisions of bounded degree graphs.

This is joint work with Shoham Letzter and Alexey Pokrovskiy.