Reals modulo 1 arise
Source: RMM Extralist 2021 A3
September 18, 2023
RMM Shortlistalgebraintervalscoveringcombinatorics
Problem Statement
A tile is a union of finitely many pairwise disjoint arcs of a unit circle . The size of ,
denoted by , is the sum of the lengths of the arcs consists of, divided by . A copy of is
a tile obtained by rotating about the centre of through some angle. Given a positive
real number , does there exist an infinite sequence of tiles satisfying the following two conditions simultaneously:
1) for all ;
2) The union of all (as runs through the positive integers) is a proper subset of for any choice of the copies , , , ? In the extralist the problem statement had the clause "three conditions" rather than two, but only two are presented, the ones you see. I am quite confident this is a typo or that the problem might have been reformulated after submission.