On the image in the torus of sparse points on expanding analytic curves

Ergodic Theory/Probability Seminar
Thu, September 1, 2022
3:00 pm - 4:00 pm
MW 154

Title:  On the image in the torus of sparse points on expanding analytic curves

Speaker:  Michael Bersudsky (OSU)

Speaker's URL:  https://sites.google.com/view/bmichael/

Abstract:  It is known that the projection to the 2-torus of the normalised parameter measure on a circle of radius $R$ in the plane becomes uniformly distributed as $R$ grows to infinity. I will discuss the following natural discrete analogue for this problem. Starting from an angle and a sequence of radii {$R_n$} which diverges to infinity, I will consider the projection to the 2-torus of the n'th roots of unity rotated by this angle and dilated by a factor of $R_n$. The interesting regime in this problem is when $R_n$ is much larger than n so that the dilated roots of unity appear sparsely on the dilated circle.
I will discuss 3 types of results:

Validity of equidistribution for all angles when the sparsity is polynomial.
Failure of equidistribution for some super polynomial dilations.
Equidistribution for almost all angles for arbitrary dilations.

I will discuss the above type of results in greater generality and I will try to explain how the theory of o-minimal structures is related to the proof.