Congruence relations of Ankeny$\unicode{x2013}$Artin$\unicode{x2013}$Chowla type for real quadratic fields

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Fellini, Nic
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929585454579712
author Fellini, Nic
author_facet Fellini, Nic
contents In 1951, Ankeny, Artin, and Chowla published a brief note containing four congruence relations involving the class number of $\mathbb{Q}(\sqrt{d})$ for positive squarefree integers $d\equiv 1 \bmod{4}$. Many of the ideas present in their paper can be seen as the precursors to the now developed theory of cyclotomic fields. Curiously, little attention has been paid to the cases of $d\equiv 2,3\bmod{4}$ in the literature. In the present work, we show that the congruences of the type proven by Ankeny, Artin, and Chowla can be seen as a special case of a more general methodology using Kubota$\unicode{x2013}$Leopoldt $p$-adic $L$-functions. Aside from the classical congruence involving Bernoulli numbers, we derive congruences involving quadratic residues and non-residues in $\mathbb{Z}/p\mathbb{Z}$ by relating these values to a well known expression for $L_p(1, χ)$. We conclude with a discussion of known counterexamples to the so-called Composite Ankeny$\unicode{x2013}$Artin$\unicode{x2013}$Chowla conjecture and relate these to special dihedral extensions of $\mathbb{Q}$.
format Preprint
id arxiv_https___arxiv_org_abs_2410_20934
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Congruence relations of Ankeny$\unicode{x2013}$Artin$\unicode{x2013}$Chowla type for real quadratic fields
Fellini, Nic
Number Theory
In 1951, Ankeny, Artin, and Chowla published a brief note containing four congruence relations involving the class number of $\mathbb{Q}(\sqrt{d})$ for positive squarefree integers $d\equiv 1 \bmod{4}$. Many of the ideas present in their paper can be seen as the precursors to the now developed theory of cyclotomic fields. Curiously, little attention has been paid to the cases of $d\equiv 2,3\bmod{4}$ in the literature. In the present work, we show that the congruences of the type proven by Ankeny, Artin, and Chowla can be seen as a special case of a more general methodology using Kubota$\unicode{x2013}$Leopoldt $p$-adic $L$-functions. Aside from the classical congruence involving Bernoulli numbers, we derive congruences involving quadratic residues and non-residues in $\mathbb{Z}/p\mathbb{Z}$ by relating these values to a well known expression for $L_p(1, χ)$. We conclude with a discussion of known counterexamples to the so-called Composite Ankeny$\unicode{x2013}$Artin$\unicode{x2013}$Chowla conjecture and relate these to special dihedral extensions of $\mathbb{Q}$.
title Congruence relations of Ankeny$\unicode{x2013}$Artin$\unicode{x2013}$Chowla type for real quadratic fields
topic Number Theory
url https://arxiv.org/abs/2410.20934