English

Number of arithmetic progressions in dense random subsets of $\mathbb{Z}/n\mathbb{Z}$

Combinatorics 2020-04-07 v2

Abstract

We examine the behavior of the number of kk-term arithmetic progressions in a random subset of Z/nZ\mathbb{Z}/n\mathbb{Z}. We prove that if a set is chosen by including each element of Z/nZ\mathbb{Z}/n\mathbb{Z} independently with constant probability pp, then the resulting distribution of kk-term arithmetic progressions in that set, while obeying a central limit theorem, does not obey a local central limit theorem. The methods involve decomposing the random variable into homogeneous degree dd polynomials with respect to the Walsh/Fourier basis. Proving a suitable multivariate central limit theorem for each component of the expansion gives the desired result.

Keywords

Cite

@article{arxiv.1907.11807,
  title  = {Number of arithmetic progressions in dense random subsets of $\mathbb{Z}/n\mathbb{Z}$},
  author = {Ross Berkowitz and Ashwin Sah and Mehtaab Sawhney},
  journal= {arXiv preprint arXiv:1907.11807},
  year   = {2020}
}

Comments

Significant new results, added authors