# Effective Ratner Theorem for $ASL(2, R)$ and the gaps of the sequence $\sqrt n$ modulo 1

1 May 2014
16:00
Ilya Vinogradov
Abstract
Let $G=SL(2,\R)\ltimes R^2$ and $\Gamma=SL(2,Z)\ltimes Z^2$. Building on recent work of Strombergsson we prove a rate of equidistribution for the orbits of a certain 1-dimensional unipotent flow of $\Gamma\G$, which projects to a closed horocycle in the unit tangent bundle to the modular surface. We use this to answer a question of Elkies and McMullen by making effective the convergence of the gap distribution of $\sqrt n$ mod 1.
• Number Theory Seminar