Square roots and lattices

Jens Marklof

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arXiv · 2406.09107

Square roots and lattices

Jens Marklof

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Abstract

We construct a point set in the Euclidean plane that elucidates the relationship between the fine-scale statistics of the fractional parts of $\sqrt n$ and directional statistics for a shifted lattice. We show that the randomly rotated, and then stretched, point set converges in distribution to a lattice-like random point process. This follows closely the arguments in Elkies and McMullen's original analysis for the gap statistics of $\sqrt{n}$ mod 1 in terms of random affine lattices [Duke Math. J. 123 (2004), 95-139]. There is, however, a curious subtlety: the limit process emerging in our construction is NOT invariant under the standard $\mathrm{SL}(2,\mathbb{R})$-action on $\mathbb{R}^2$.

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Jens Marklof. 2024-06-13. Square roots and lattices. https://arxiv.org/abs/2406.09107

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