Diophantine approximation with sums of two squares

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Baier, Stephan, Rahaman, Habibur
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866908932188930048
author Baier, Stephan
Rahaman, Habibur
author_facet Baier, Stephan
Rahaman, Habibur
contents For any given positive definite binary quadratic form $Q$ with integer coefficients, we establish two results on Diophantine approximation with integers represented by $Q$. Firstly, we show that for every irrational number $α$, there exist infinitely many positive integers $n$ represented by $Q$ and satisfying $||αn||<n^{-(1/2-\varepsilon)}$ for any fixed but arbitrarily small $\varepsilon>0$. This is an easy consequence of a result by Cook on small fractional parts of diagonal quadratic forms. Secondly, we give a quantitative version with a lower bound of this result when the exponent $1/2-\varepsilon$ is replaced by any fixed $γ<3/7$. To this end, we use the Voronoi summation formula and a bound for bilinear forms with Kloosterman sums to fixed moduli by Kerr, Shparlinski, Wu and Xi.
format Preprint
id arxiv_https___arxiv_org_abs_2504_09650
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Diophantine approximation with sums of two squares
Baier, Stephan
Rahaman, Habibur
Number Theory
11J25, 11J54, 11J71, 11L05, 11E25
For any given positive definite binary quadratic form $Q$ with integer coefficients, we establish two results on Diophantine approximation with integers represented by $Q$. Firstly, we show that for every irrational number $α$, there exist infinitely many positive integers $n$ represented by $Q$ and satisfying $||αn||<n^{-(1/2-\varepsilon)}$ for any fixed but arbitrarily small $\varepsilon>0$. This is an easy consequence of a result by Cook on small fractional parts of diagonal quadratic forms. Secondly, we give a quantitative version with a lower bound of this result when the exponent $1/2-\varepsilon$ is replaced by any fixed $γ<3/7$. To this end, we use the Voronoi summation formula and a bound for bilinear forms with Kloosterman sums to fixed moduli by Kerr, Shparlinski, Wu and Xi.
title Diophantine approximation with sums of two squares
topic Number Theory
11J25, 11J54, 11J71, 11L05, 11E25
url https://arxiv.org/abs/2504.09650