Imaginary Multiquadratic Fields of Class Number 1

关于完全实多元二次数字段形状分布的论文

On the distribution of shapes of totally real multiquadratic number fields

本文研究了完全实多元二次数字段的形状分布，证明其由特定环面轨道上的测度限制所支配，解决了Haidar的猜想。

关于某些多二次域的单位群

On the unit group of some multiquadratic fields

本文计算了满足特定同余条件的两个多二次域的单位群和2-类数，给出了精确结果。

Triquadratic p-Rational Fields

In his work about Galois representations, Greenberg conjectured the existence, for any odd prime p and any positive integer t, of a multiquadratic p-rational number field of degree 2 t. In this article, we prove that there exists infinitely many primes p such that the triquadratic field Q(p(p + 2), p(p -- 2), i) is p-rational. To do this, we use an analytic result, proved apart in section \S4, providing us with infinitely many prime numbers p such that p + 2 et p -- 2 have ''big'' square factors. Therefore the related imaginary quadratic subfields Q(i $\sqrt$ p + 2), Q(i $\sqrt$ p -- 2) and Q(…

Periodic sequences of p-class tower groups

Recent examples of periodic bifurcations in descendant trees of finite p-groups with p in {2,3} are used to show that the possible p-class tower groups G of certain multiquadratic fields K with p-class group of type (2,2,2), resp. (3,3), form periodic sequences in the descendant tree of the elementary abelian root C(2)xC(2)xC(2), resp. C(3)xC(3). The particular vertex of the periodic sequence which occurs as the p-class tower group G of an assigned field K is determined uniquely by the p-class number of a quadratic, resp. cubic, auxiliary field k, associated unambiguously to K. Consequently, t…

Notes on the divisibility of the class numbers of certain imaginary quadratic fields

In this paper, we construct certain infinite families of imaginary quadratic fields whose class number is divisible by a given positive integer.

Nagell-Lutz定理在虚二次域中的应用及二次域类数群的研究

Nagell-Lutz Theorem for Imaginary Quadratic Fields and class groups of quadratic fields

本文证明了虚二次域中类数为一的Nagell-Lutz定理，并探讨了二次域类数群的相关性质。

On 2-Class field towers of some imaginary quadratic number fields

We construct an infinite family of imaginary quadratic number fields with 2-class groups of type (2,2,2) whose Hilbert 2-class fields are finite.

Ring class invariants over imaginary quadratic fields

We show by adopting Schertz's argument with the Siegel-Ramachandra invariant that singular values of certain quotients of the $Δ$-function generate ring class fields over imaginary quadratic fields.

Euclidean Ideals in Quadratic Imaginary Fields

We classify all quadratic imaginary number fields that have a Euclidean ideal class. There are seven of them, they are of class number at most two, and in each case the unique class that generates the class-group is moreover norm-Euclidean.

虚双循环双二次数域的类数

Class numbers of Imaginary bicyclic biquadratic number fields

本文提出一种利用类数整除$2n$的虚二次数域列表，计算类数为$n$的虚双循环双二次数域及其类群结构的方法，并列出了类数为4、6和7的域及其子域的类群结构。

Indivisibility of class numbers of imaginary quadratic fields

We quantify a recent theorem of Wiles on class numbers of imaginary quadratic fields by proving an estimate for the number of negative fundamental discriminants down to -X whose class numbers are indivisible by a given prime and whose imaginary quadratic fields satisfy any given set of local conditions. This estimate matches the best results in the direction of the Cohen-Lenstra heuristics for the number of imaginary quadratic fields with class number indivisible by a given prime. This general result is applied to study rank 0 twists of certain elliptic curves.

2的幂次阶虚循环数域的类数问题

A class number problem for imaginary cyclic number fields of 2-power degrees

本文将M. K. Ram关于虚循环四次数域类数不等于特定素数的结论，大幅推广至2的幂次阶非二次虚循环数域且类数非素数的情形。

Dedekind sums and class numbers of imaginary abelian number fields

As a consequence of their work, Bruce C. Berndt and Ronald J. Evans in 1977 and Larry Joel Goldstein and Michael Razar in 1976 obtained a formula for the square of the class number of an imaginary quadratic number field in terms of Dedekind sums. Here we focus only on this formula and give a new short and simple proof of it. We finally express the relative class numbers of imaginary abelian number fields in terms of Dedekind sums.

阿贝尔数域的虚对数类

Imaginary logarithmic classes of abelian number fields

本文研究阿贝尔数域的虚对数类，计算对数类群的等同型分量并将Gold判据推广至该情形，涵盖半单与非半单情形。

4-ranks and the general model for statistics of ray class groups of imaginary quadratic number fields

We extend the Cohen-Lenstra heuristics to the setting of ray class groups of imaginary quadratic number fields, viewed as exact sequences of Galois modules. By asymptotically estimating the mixed moments governing the distribution of a cohomology map, we prove these conjectures in the case of $4$-ranks.

Divisibility of the class numbers of imaginary quadratic fields

For a given odd integer $n>1$, we provide some families of imaginary quadratic number fields of the form $\mathbb{Q}(\sqrt{x^2-t^n})$ whose ideal class group has a subgroup isomorphic to $\mathbb{Z}/n\mathbb{Z}$.

Growth of Odd Torsion Over Imaginary Quadratic Fields of Class Number 1

Let $K$ be a non-cylotomic imaginary quadratic field of class number 1 and $E/K$ is an elliptic curve with $E(K)[2]\simeq \mathbb{Z}_1.$ We determine the odd-order torsion groups that can arise as $E(L)_{\text{tor}}$ where $L$ is a quadratic extension of $K.$

Exponents of class groups of certain imaginary quadratic fields

Let $n>1$ be an odd integer. We prove that there are infinitely many imaginary quadratic fields of the form $\mathbb{Q}(\sqrt{x^2-2y^n})$ whose ideal class group has an element of order $n$. This family gives a counter example to a conjecture by H. Wada \cite{WA70} on the structure of ideal class groups.

A computable formula for the class number of the imaginary quadratic field $Q(\sqrt{-p}), \ p=4n-1$

A formula for the class number $h$ of the imaginary quadratic field $Q(\sqrt{-p}$ is obtained by counting on a specific way the quadratic residues of a prime number of the form $p=4n-1.$ Formulas for the sum of the quadratic residues are also found.

A Maass Lifting of $Θ^3$ and Class Numbers of Real and imaginary Quadratic Fields

We give an explicit construct of a harmonic weak Maass form $F_Θ$ that is a "lift" of $Θ^3$, where $Θ$ is the classical Jacobi theta function. Just as the Fourier coefficients of $Θ^3$ are related to class numbers of imaginary quadratic fields, the Fourier coefficients of the "holomorphic part" of $F_Θ$ are associated to class numbers of real quadratic fields.

Normal bases of ray class fields over imaginary quadratic fields

We develop a criterion for a normal basis, and prove that the singular values of certain Siegel functions form normal bases of ray class fields over imaginary quadratic fields other than $\mathbb{Q}(\sqrt{-1})$ and $\mathbb{Q}(\sqrt{-3})$. This result would be an answer for the Lang-Schertz conjecture on a ray class field with modulus generated by an integer ($\geq2$).

The number of imaginary quadratic fields with prime discriminant and class number up to $H$

In this paper, we obtain an asymptotic formula for the number of imaginary quadratic fields with prime discriminant and class number up to $H$, as $H\to \infty$. Previously, such an asymptotic was only known under the assumption of the Generalized Riemann Hypothesis, by the recent work of Holmin, Jones, Kurlberg, McLeman and Petersen.

Imaginary quadratic fields with Cl_2(k) = (2,2,2)

In this article we classify the complex quadratic number fields k with 2-class group of type (2,2,2) whose Hilbert 2-class fields have a 2-class group of rank 2, and then determine the length of their 2-class field towers.

$2$-class groups of cyclotomic towers of imaginary biquadratic fields and applications

Let $d$ be a positive square-free integer. In this paper we shall investigate the structure of the $2$-class group of the cyclotomic $\mathbb{Z}_2$-extension of the imaginary biquadratic number field $\mathbb{Q}(\sqrt{d},\sqrt{-1})$. Furthermore, we deduce the structure of the $2$-class group of cyclotomic $\mathbb{Z}_2$-extension of $\mathbb{Q}(\sqrt{-d})$.

On the $p$-divisibility of class numbers of an infinite family of imaginary quadratic fields $\mathbb{Q} (\sqrt{d})$ and $\mathbb{Q} (\sqrt{d+1}).$

For any odd prime $p,$ we construct an infinite family of pairs of imaginary quadratic fields $\mathbb{Q}(\sqrt{d}),\mathbb{Q}(\sqrt{d+1})$ whose class numbers are both divisible by $p.$ One of our theorems settles Iizuka's conjecture for the case $n=1$ and $p >2.$

The number of imaginary quadratic fields with a given class number

We investigate the number ${\Cal F}(h)$ of imaginary quadratic fields with class number $h$. We establish an asymptotic formula for the average value of ${\Cal F}(h)$. We also establish a modest non-trivial upper bound for ${\Cal F}(h)$ and give an application to a question of Rosen and Silverman on the odd part of the class number. Finally, we speculate on the asymptotic nature of ${\Cal F}(h)$.

Class Number of the Imaginary Quadratic Field and Quadratic Residues Identities

A formula for the sum of quadratic residues modulus a prime $p=4n-1$ is studied. We relate some terms on this formula with roots of quadratics and provide an exhaustive analysis of new concepts based on these roots. A number of formulas for the sum of the quadratic residues are obtained. We finalize the paper by obtaining several identities involving $h(-p)$ the class number of the imaginary quadratic field $\mathbb Q(\sqrt{-p}).$

On the exponents of class groups of some families of imaginary quadratic fields

Let $a\geq 1$ and $n>1$ be odd integers. For a given prime $p$, we prove under certain conditions that the class groups of imaginary quadratic fields $\mathbb{Q}(\sqrt{a^2-4p^n})$ have a subgroup isomorphic to $\mathbb{Z}/n\mathbb{Z}$. We also show that this family of fields has infinitely many members with the property that their class groups have a subgroup isomorphic to $\mathbb{Z}/n\mathbb{Z}$. In addition, we deduce some unconditional results concerning the divisibility of the class numbers of certain imaginary quadratic fields. At the end, we provide some numerical examples to verify our…

On the average of the number of imaginary quadratic fields with a given class number

Let $\mathcal{F}(h)$ be the number of imaginary quadratic fields with class number $h$. In this note, we improve the error term in Soundararajan's asymptotic formula for the average of $\mathcal{F}(h)$. Our argument leads to a similar refinement of the asymptotic for the average of $\mathcal{F}(h)$ over odd $h$, which was recently obtained by Holmin, Jones, Kurlberg, McLeman and Petersen.

Annihilators of the ideal class group of a cyclic extension of an imaginary quadratic field

The aim of this paper is to study the group of elliptic units of a cyclic extension $L$ of an imaginary quadratic field $K$ such that the degree $[L:K]$ is a power of an odd prime $p$. We construct an explicit root of the usual top generator of this group and we use it to obtain an annihilation result of the $p$-Sylow subgroup of the ideal class group of $L$.

On the Selmer groups and Mordell-Weil groups of elliptic curves $ y^{2} = x (x \pm p) (x \pm q) $ over imaginary quadratic number fields of class number one

Let $ p $ and $ q $ be odd prime numbers with $ q - p = 2, $ the $φ-$Selmer groups, Shafarevich-Tate groups ($ φ- $ and $ 2-$part) and their dual ones as well the Mordell-Weil groups of elliptic curves $ y^{2} = x (x \pm p) (x \pm q) $ over imaginary quadratic number fields of class number one are determined explicitly in many cases.

Mild pro-$p$-groups and $p$-extensions of imaginary quadratic fields with non-trivial $p$-class group

Let $k$ be an imaginary quadratic field and $p$ an odd prime number such that the $p$-rank of the class group of $k$ is one. Let $S$ be a finite set of places of $k$ distinct from $p$-adic places. We give sufficient conditions for the Galois group $G_S$, of the maximal pro-$p$-extension of $k$ which is unramified outside $S$, to be \textit{mild}, hence of cohomological dimension $2$.

Class groups of imaginary quadratic fields of $3$-rank at least $2$

We produce an infinite family of imaginary quadratic fields whose ideal class groups have $3$-rank at least $2$.

Imaginary quadratic fields with 2-class group of type $(2,2^\ell)$

We prove that for any given positive integer $\ell$ there are infinitely many imaginary quadratic fields with 2-class group of type $(2,2^\ell)$, and provide a lower bound for the number of such groups with bounded discriminant for $\ell\ge2$. This work is based on a related result for cyclic 2-class groups by Dominguez, Miller and Wong, and our proof proceeds similarly. Our proof requires introducing congruence conditions into Perelli's result on Goldbach numbers represented by polynomials, which we establitish in some generality.

$X_1(16)$上虚二次点的类群

Class groups of imaginary quadratic points on $X_1(16)$

针对David Krumm提出的12年问题，研究建立通用框架分析双曲曲线虚二次点类群整除性，证明特定条件下虚二次域类数可被10整除，给出肯定回答。

Ray class invariants over imaginary quadratic fields

Let $K$ be an imaginary quadratic field of discriminant less than or equal to -7 and $K_{(N)}$ be its ray class field modulo $N$ for an integer $N$ greater than 1. We prove that singular values of certain Siegel functions generate $K_{(N)}$ over $K$ by extending the idea of our previous work. These generators are not only the simplest ones conjectured by Schertz, but also quite useful in the matter of computation of class polynomials. We indeed give an algorithm to find all conjugates of such generators by virtue of Gee and Stevenhagen.

具有大类数的虚双二次域的一个无限族

An infinite family of imaginary biquadratic fields with a large class number

本文通过组合两个虚二次域族，利用Kuroda类数公式，构造了具有大类数的虚双二次域的无限族，旨在类群中获得高阶元素。

Bounds on the Mordell--Weil rank of elliptic curves over imaginary quadratic number fields with class number 1

We generalize the lemmas of Thomas Kretschmer to arbitrary number fields, and apply them with a 2-descent argument to obtain bounds for families of elliptic curves over certain imaginary quadratic number fields with class number 1. One such family occurs in the congruent number problem. We consider the congruent number problem over these quadratic number fields, and subject to the finiteness of Sha, we show that there are infinitely many numbers that are not congruent over Q but become congruent over $Q(ζ_3)$.

On the rank of the $2$-class group of some imaginary triquadratic number fields

Let $d$ be an odd square-free integer and $ζ_8$ a primitive $8$-th root of unity. The purpose of this paper is to investigate the rank of the $2$-class group of the fields $L_d=\mathbb{Q}(ζ_8,\sqrt{d})$.

利用类数为三的虚二次域具有复乘的椭圆曲线进行素性证明

Primality proving using elliptic curves with complex multiplication by imaginary quadratic fields of class number three

本文将Abatzoglou等人的复乘椭圆曲线素性证明框架推广到类数为三的虚二次域，利用2分裂的类数三虚二次域得到更高效的素性证明算法，并给出基于Q(√-23)和Q(√-31)的两个特殊整数序列及计算结果。

2-幂次虚非CM域

Imaginary Non-CM Fields of $2$-Power Degree

本文提出研究任意2-幂次虚非CM域的新方法，证明次数大于16的二面体域结构，并完整分类了次数16类数1的104个虚非CM域，连同5个CM域完成该次数所有虚域分类。

The class number formula for imaginary quadratic fields

It is shown that the class number for negative discriminant $D$ can be expressed in terms of the base $B$ expansions of reduced fractions $\frac{x}{|D|}$, where $B$ is an integer prime to $D$. This result is then formulated to obtain information about the distribution of the values of $χ(x)$, where $χ$ is the quadratic character associated to $D$. This leads to simplified formulas for the class number in certain cases.

Partitions Associated to Class Groups of Imaginary Quadratic Number Fields

We investigate properties of attainable partitions of integers, where a partition $(n_1,n_2, \dots, n_r)$ of $n$ is attainable if $\sum (3-2i)n_i\geq 0$. Conjecturally, under an extension of the Cohen and Lenstra heuristics by Holmin et. al., these partitions correspond to abelian $p$-groups that appear as class groups of imaginary quadratic number fields for infinitely many odd primes $p$. We demonstrate a connection to partitions of integers into triangular numbers, construct a generating function for attainable partitions, and determine the maximal length of attainable partitions.

On the simultaneous $3$-divisibility of class numbers of triples of imaginary quadratic fields

Let $k \geq 1$ be a cube-free integer with $k \equiv 1 \pmod {9}$ and $\gcd(k, 7\cdot 571)=1$. In this paper, we prove the existence of infinitely many triples of imaginary quadratic fields $\mathbb{Q}(\sqrt{d})$, $\mathbb{Q}(\sqrt{d+1})$ and $\mathbb{Q}(\sqrt{d+k^2})$ with $d \in \mathbb{Z}$ such that the class number of each of them is divisible by $3$. This affirmatively answers a weaker version of a conjecture of Iizuka \cite{iizuka-jnt}.

On correlations between class numbers of imaginary quadratic fields

Let $h(-n)$ be the class number of the imaginary quadratic field with discriminant $-n$. We establish an asymtotic formula for correlations involving $h(-n)$ and $h(-n-l)$, over fundamental discriminants that avoid the congruence class $1\pmod{8}$. Our result is uniform in the shift $l$, and the proof uses an identity of Gauss relating $h(-n)$ to representations of integers as sums of three squares. We also prove analogous results on correlations involving $r_Q(n)$, the number of representations of an integer $n$ by an integral positive definite quadratic form $Q$.

虚双二次域的理想类群

Class groups of imaginary biquadratic fields

本文构造了两族各含无穷多个成员且理想类群较大的虚双二次域，分别借助椭圆曲线及其二次扭曲，以及椭圆曲线与超椭圆曲线的组合，并利用 Soleng 与 Banerjee–Hoque 的结果。

与虚二次域类数相关的取整函数求和

Sums of the floor function related to class numbers of imaginary quadratic fields

本文扩展了Bunyakovsky关于平方根取整函数求和的恒等式至p≡3(mod 4)及合数情形，并用虚二次域类数表达结果。

On Serre's modularity conjecture and Fermat's equation over quadratic imaginary fields of class number one

In the present article, we extend previous results of the author and we show that when $K$ is any quadratic imaginary field of class number one, Fermat's equation $a^p+b^p+c^p=0$ does not have integral coprime solutions $a,b,c \in K \setminus \{ 0 \}$ such that $2 \mid abc$ and $p \geq 19$ is prime. The results are conjectural upon the veracity of a natural generalisation of Serre's modularity conjecture.

Imaginary quadratic number fields with class groups of small exponent

Let $D<0$ be a fundamental discriminant and denote by $E(D)$ the exponent of the ideal class group $\text{Cl}(D)$ of $K={\mathbb Q}(\sqrt{D})$. Under the assumption that no Siegel zeros exist we compute all such $D$ with $E(D)$ is a divisor of $8$. We compute all $D$ with $|D|\leq 3.1\cdot 10^{20}$ such that $E(D)\leq 8$.

Imaginary quadratic fields k with Cl_2(k) = (2,2^m) and Rank Cl_2(k^1) = 2

We classify all complex quadratic number fields with 2-class group of type (2,2^m) whose Hilbert 2-class fields have class groups of 2-rank equal to 2. These fields all have 2-class field tower of length 2. We still don't know examples of fields with 2-class field tower of length 3, but the smallest candidate is the field with discriminant -1015.

Construction of class fields over imaginary biquadratic fields

Let $K$ be an imaginary biquadratic field and $K_1$, $K_2$ be its imaginary quadratic subfields. For integers $N>0$, $μ\geq 0$ and an odd prime $p$ with $\gcd(N,p)=1$, let $K_{(Np^μ)}$ and $(K_i)_{(Np^μ)}$ for $i=1,2$ be the ray class fields of $K$ and $K_i$, respectively, modulo $Np^μ$. We first present certain class fields $\widetilde{K_{N,p,μ}^{1,2}}$ of $K$, in the sense of Hilbert, which are generated by Siegel-Ramachandra invariants of $(K_i)_{(Np^{μ+1})}$ for $i=1,2$ over $K_{(Np^μ)}$ and show that $K_{(Np^{μ+1})}=\widetilde{K_{N,p,μ}^{1,2}}$ for almost all $μ$.

类数1的虚二次域上椭圆曲线的非循环挠群

Non-cyclic Torsion of Elliptic Curves Over Imaginary Quadratic Fields of Class Number 1

本文研究类数1非分圆虚二次域上具有全2-挠点的椭圆曲线，确定了其在基域二次扩张上的挠群所有可能结构。

Missing class groups and class number statistics for imaginary quadratic fields

The number F(h) of imaginary quadratic fields with a given class number h is of classical interest: Gauss' class number problem asks for a determination of those fields counted by F(h). The unconditional computation of F(h) for h up to 100 was completed by M. Watkins, using ideas of Goldfeld and Gross-Zagier; Soundararajan has more recently made conjectures about the order of magnitude of F(h) as h increases without bound, and determined its average order. In the present paper, we refine Soundararajan's conjecture to a conjectural asymptotic formula and also consider the subtler problem of det…

Steinitz classes and partial genera of unimodular lattices over imaginary-quadratic fields

In this paper we first of all determine all possible genera of (odd and even) definite unimodular lattices over an imaginary-quadratic field. The main questions are whether the partial class numbers of lattices with given Steinitz class within one genus are equal for all occuring Steinitz classes and whether the partial masses of those partial genera are equal. We show that the answer to the first question in general is "no" by giving a counter example, while the answer to the second question is "yes" by proving a mass formula for partial masses. Finally, we determine a list of all single-clas…