Search arXivSearch

arXiv · 1903.01881

Good weights for the Erdős discrepancy problem

Abstract

The Erdős discrepancy problem, now a theorem by T. Tao, asks whether every sequence with values plus or minus one has unbounded discrepancy along all homogeneous arithmetic progressions. We establish weighted variants of this problem, for weights given either by structured sequences that enjoy some irrationality features, or certain random sequences. As an intermediate result, we establish unboundedness of weighted sums of bounded multiplicative functions and products of shifts of such functions. A key ingredient in our analysis for the structured weights, is a structural result for measure preserving systems naturally associated with bounded multiplicative functions that was recently obtained in joint work with B. Host.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Nikos Frantzikinakis. 2020-07-15. Good weights for the Erdős discrepancy problem. https://arxiv.org/abs/1903.01881

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

On single-variable Witten zeta functions of rank two and three

By introducing a novel integration kernel for the Mellin transform, we uncover many previously unknown and intriguing properties of the Witten zeta functions of rank two and three. Detailed results concerning their pole locations, residues, and special values are obtained. We propose a non-trivial conjecture regarding their derivatives at the origin, which seems to encode deep information about the root system. We also discuss their behavior at negative integers, highlighting a connection with Eisenstein series and a $p$-adic observation.

math.NT

On graded Lie algebras associated to once-punctured elliptic curves with complex multiplication

We study a graded Lie algebra arising from the Galois action on the pro-$p$ fundamental group of a once-punctured elliptic curve with complex multiplication. Among other things, we provide a minimal generating set of the rationalized Lie algebra under suitable assumptions. The proof is based on a slight variant of the theory of weighted completion of profinite groups developed by Hain and Matsumoto.

math.NT

Burgess-type volume dependent bounds for character sums over $\mathbb{F}_{p^n}$

We establish a Burgess-type bound for short multiplicative character sums over finite fields $\mathbb{F}_{p^n}$. Let \[ B=\left\{\sum_{i=1}^{n}x_iω_i: N_i+1\le x_i\le N_i+H_i,1\le i\le n\right\}\subseteq\mathbb{F}_{p^n}, \] where $1\le H_i\le p$ for all $1\le i\le n$, and the side lengths satisfy $H_1\le H_2\le\cdots\le H_n.$ We prove that if the side lengths satisfy certain lower bounds in terms of the two largest side lengths, then a nontrivial cancellation occurs in the character sum over the boxes. This generalizes the work of Gabdullin \cite{GB} in dimensions $n=2,3$ to arbitrary dimension. This also generalizes the character sum estimate of Konyagin \cite{Kon} where each of the side lengths of the boxes are greater than $p^{1/4}$. The proof combines techniques from the geometry of numbers, multiplicative energy estimates, and Katz's bounds for multiplicative character sums.

math.NT