Time:  3:30pm  4:30 pm 
Room: 
Wean Hall 8220

Speaker: 
Andy Zucker Department of Mathematical Sciences CMU 
Title: 
An ultrafilter proof of the 2dimensional HalpernLaüchli Theorem

Abstract: 
We will discuss the HalpernLaüchli Theorem and provide a new proof in dimension 2. The idea is to use an ultrafilter on ω to turn combinatorics on trees into combinatorics on the branches, that is Cantor space. Time permitting, we will discuss obstacles to generalizing the proof to higher dimensions. 