A1 Refereed original research article in a scientific journal

On the Local Fourier Uniformity Problem for Small Sets




AuthorsKanigowski, Adam; Lemańczyk, Mariusz; Richter, Florian K.; Teräväinen, Joni

PublisherOXFORD UNIV PRESS

Publishing placeOXFORD

Publication year2024

JournalInternational Mathematics Research Notices

Journal name in sourceINTERNATIONAL MATHEMATICS RESEARCH NOTICES

Journal acronymINT MATH RES NOTICES

Volume2024

Issue15

First page 11488

Last page11512

Number of pages25

ISSN1073-7928

eISSN1687-0247

DOIhttps://doi.org/10.1093/imrn/rnae134

Web address https://doi.org/10.1093/imrn/rnae134

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/457144882


Abstract

We consider vanishing properties of exponential sums of the Liouville function of the form

lim(->infinity) lim(->infinity) sup 1/log Sigma(<=) 1/ sup(is an element of)|1/ Sigma (<=) ( + )(2)| = 0,

where subset of . The case = corresponds to the local 1-Fourier uniformity conjecture of Tao, a central open problem in the study of multiplicative functions with far-reaching number-theoretic applications. We show that the above holds for any closed set subset of of zero Lebesgue measure. Moreover, we prove that extending this to any set with non-empty interior is equivalent to the = case, which shows that our results are essentially optimal without resolving the full conjecture. We also consider higher-order variants. We prove that if the linear phase (2) is replaced by a polynomial phase (2) for >= 2 then the statement remains true for any set of upper box-counting dimension <1/. The statement also remains true if the supremum over linear phases is replaced with a supremum over all nilsequences coming form a compact countable ergodic subsets of any -step nilpotent Lie group. Furthermore, we discuss the unweighted version of the local 1-Fourier uniformity problem, showing its validity for a class of "rigid" sets (of full Hausdorff dimension) and proving a density result for all closed subsets of zero Lebesgue measure.


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Funding information in the publication
The research of the second author was partially supported by Narodowe Centrum Nauki grant UMO-2019/33/B/ST1/00364. The research of the fourth author was supported by a von Neumann Fellowship and funding from European Union’s Horizon Europe research and innovation programme under Marie Skłodowska-Curie grant agreement No 101058904. The third and fourth author were supported by (NSF grant DMS-1926686).


Last updated on 2025-27-01 at 19:38