Heegner point constructions and fundamental units in cubic fields

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autore principale: Karighattam, Arav V.
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866910767006089216
author Karighattam, Arav V.
author_facet Karighattam, Arav V.
contents We use Heegner points to prove the existence of nontorsion rational points on the elliptic curve $y^2 = x^3 + D$ for any rational number $D=a/b$ such that $a$ and $b$ are squarefree integers for which $6$, $a$, and $b$ are pairwise relatively prime, $a\equiv b\pmod{4}$, $\lvert a\rvert\lvert b\rvert^{-1}\equiv5$ or $7\pmod{9}$, and $h_K$ is odd, where $K:=\mathbb{Q}(\sqrt[3]{D})$. In particular, we show that under these assumptions, the elliptic curve with equation $y^2 = x^3 + D$ has algebraic rank $1$ and the elliptic curve with equation $y^2 = x^3 - D$ has algebraic rank $0$. This follows from our new expression for the fundamental unit of $\mathscr{O}_K$ in terms of the class number $h_K$ and the norm of a special value of a modular function of level $6$, for any integer $D$ relatively prime to $6$, not congruent to $\pm1\pmod{9}$, for which no exponent in its prime factorization is a multiple of $3$. This expression is an analogue of a theorem of Dirichlet in 1840 relating the fundamental unit of a real quadratic field to its class number and a product of cyclotomic units.
format Preprint
id arxiv_https___arxiv_org_abs_2407_12834
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Heegner point constructions and fundamental units in cubic fields
Karighattam, Arav V.
Number Theory
We use Heegner points to prove the existence of nontorsion rational points on the elliptic curve $y^2 = x^3 + D$ for any rational number $D=a/b$ such that $a$ and $b$ are squarefree integers for which $6$, $a$, and $b$ are pairwise relatively prime, $a\equiv b\pmod{4}$, $\lvert a\rvert\lvert b\rvert^{-1}\equiv5$ or $7\pmod{9}$, and $h_K$ is odd, where $K:=\mathbb{Q}(\sqrt[3]{D})$. In particular, we show that under these assumptions, the elliptic curve with equation $y^2 = x^3 + D$ has algebraic rank $1$ and the elliptic curve with equation $y^2 = x^3 - D$ has algebraic rank $0$. This follows from our new expression for the fundamental unit of $\mathscr{O}_K$ in terms of the class number $h_K$ and the norm of a special value of a modular function of level $6$, for any integer $D$ relatively prime to $6$, not congruent to $\pm1\pmod{9}$, for which no exponent in its prime factorization is a multiple of $3$. This expression is an analogue of a theorem of Dirichlet in 1840 relating the fundamental unit of a real quadratic field to its class number and a product of cyclotomic units.
title Heegner point constructions and fundamental units in cubic fields
topic Number Theory
url https://arxiv.org/abs/2407.12834