A1 Refereed original research article in a scientific journal

An explicit Pólya-Vinogradov inequality via Partial Gaussian sums




AuthorsMatteo Bordignon, Bryce Kerr

PublisherAMER MATHEMATICAL SOC

Publication year2020

JournalTransactions of the American Mathematical Society

Journal name in sourceTRANSACTIONS OF THE AMERICAN MATHEMATICAL SOCIETY

Journal acronymT AM MATH SOC

Volume373

Issue9

First page 6503

Last page6527

Number of pages25

ISSN0002-9947

eISSN1088-6850

DOIhttps://doi.org/10.1090/tran/8138


Abstract
In this paper we obtain a new fully explicit constant for the Polya-Vinogradov inequality for squarefree modulus. Given a primitive character chi to squarefree modulus q, we prove the following upper bound:vertical bar Sigma(1 <= n <= N) chi(n)vertical bar <= c root q log q,where c = 1/(2 pi(2)) + o(1) for even characters and c = 1/(4 pi) + o(1) for odd characters, with an explicit o(1) term. This improves a result of Frolenkov and Soundararajan for large q. We proceed via partial Gaussian sums rather than the usual Montgomery and Vaughan approach of exponential sums with multiplicative coefficients. This allows a power saving on the minor arcs rather than a factor of log q as in previous approaches and is an important factor for fully explicit bounds.



Last updated on 2024-26-11 at 21:55