Infinite Combinatorics Seminar (BIU)
Room 201, Building 216, Bar-Ilan University
Speaker: Ashutosh Kumar (HUJI)
Title: Avoiding rational distances
Abstract: Komjath has asked the following question: Let X be a subset of Euclidean space. Must there exist a subset Y of X such that X and Y have same outer measure and the distance between any two points in Y is irrational?
We’ll show that this is true in dimension one. Our proof relies on some work of Gitik and Shelah on forcings with sigma ideals.