Fibonacci Sequences And Real Quadratic p-Rational Fields

斐波那契数与有理丢番图方程的韦达跳跃

Fibonacci Numbers and Vieta Jumping for a Rational Diophantine Equation

利用韦达跳跃方法，完全分类了有理丢番图方程 (a+1)/b + (b+1)/a = k 的正整数解，证明 k 只能为 3 或 4，且解与斐波那契数相关。

Counting Exceptional Points for Rational Numbers Associated to the Fibonacci Sequence

If $α$ is a non-zero algebraic number, we let $m(α)$ denote the Mahler measure of the minimal polynomial of $α$ over $\mathbb Z$. A series of articles by Dubickas and Smyth, and later by the author, develop a modified version of the Mahler measure called the $t$-metric Mahler measure, denoted $m_t(α)$. For fixed $α\in \bar{\mathbb Q}$, the map $t\mapsto m_t(α)$ is continuous, and moreover, is infinitely differentiable at all but finitely many points, called {\it exceptional points} for $α$. It remains open to determine whether there is a sequence of elements $α_n\in \bar{\mathbb Q}$ such that …

关于某些 Fibonacci 表示

On certain Fibonacci representations

本文探讨如何利用 Fibonacci 数生成其他递归序列，将某些整数递归序列族表示为 Fibonacci 数的有理多项式线性组合。

ℓ-广义斐波那契zeta函数的解析延拓

Analytic continuation of $\ell$-generalized Fibonacci zeta function

本文定义ℓ-广义斐波那契zeta函数，研究其到全复平面的解析延拓，计算奇点与留数，并证明其在负整数处取有理数值。

On Higher Dimensional Fibonacci Numbers, Chebyshev Polynomials and Sequences of Vector Convergents

We study higher-dimensional interlacing Fibonacci sequences, generated via both Chebyshev type functions and $m$-dimensional recurrence relations. For each integer $m$, there exist both rational and integer versions of these sequences, where the underlying prime congruence structures of the rational sequence denominators enables the integer sequence to be recovered. From either the rational or the integer sequences we construct sequences of vectors in $\mathbb{Q}^m$, which converge to irrational algebraic points in $\mathbb{R}^m$. The rational sequence terms can be expressed as simple recurren…

斐波那契泽塔函数与延拓

The Fibonacci Zeta Function and Continuation

本文引入一类推广普通斐波那契泽塔函数的狄利克雷级数，给出将其亚纯延拓至复数域的三种方法，包括两种经典解析方法与一种基于移位卷积和模形式的方法。

Accelerations of generalized Fibonacci sequences

In this paper we study how to accelerate the convergence of the ratios (x_n) of generalized Fibonacci sequences. In particular, we provide recurrent formulas in order to generate subsequences (x_{g_n}) for every linear recurrent sequence (g_n) of order 2. Using these formulas we prove that some approximation methods, as secant, Newton, Halley and Householder methods, can generate subsequences of (x_n). Moreover, interesting properties on Fibonacci numbers arise as an application. Finally, we apply all the results to the convergents of a particular continued fraction which represents quadratic …

二次代数中幂的通用恒等式及斐波那契恒等式的矩阵导出

Quadratic Reduction and Classical Multiple-Index Fibonacci-Lucas Identities

研究二次代数中元素幂的通用恒等式，通过矩阵迹和行列式推导斐波那契数列的二项式展开公式，揭示恒等式源于普遍代数原理。

Fibonacci numbers and the golden ratio

In this expository paper written to commemorate Fibonacci Day 2016, we discuss famous relations involving the Fibonacci sequence, the golden ratio, continued fractions and nested radicals, and show how these fit into a more general framework stemming from the quadratic formula.

Some Weighted Generalized Fibonacci Number Summation Identities, Part 1

The Fibonacci number is the residue of a rational function, from which follows that Fibonacci number summation identities can be derived with the integral representation method, a method also used to derive combinatorial identities. A number of weighted generalized Fibonacci number summation identities are derived this way. From these identities some infinite series, generating functions and convolution identities are obtained. In addition, some weighted generalized Fibonacci number summation identities with binomial coefficients are derived. Many examples of both types of summation identities…

Multivariate Lucas Polynomials and Ideal Classes in Quadratic Number Fields

In this work, by using Pauli matrices, we introduce four families of polynomials indexed over the positive integers. These polynomials have rational or imaginary rational coefficients. It turns out that two of these families are closely related to classical Lucas and Fibonacci polynomial sequences and hence to Lucas and Fibonacci numbers. We use one of these families to give a geometric interpretation of the 200 years old class number problems of Gauss, which is equivalent to the study of narrow ideal classes in real quadratic number fields.

The conumerator

In this paper, we answer the question: "what is the qth Fibonacci number, where q is a positive rational?". The answer is the codenominator function, which is an integral-valued map. It is defined via a pair of functional equations. Many Fibonacci identities in the literature are valid for the codenominator. It is related to the recently introduced involution Jimm and to the outer automorphism of PGL(2,Z)

Half-integral weight modular forms and real quadratic $p$-rational fields

Using half-integral weight modular forms we give a criterion for the existence of real quadratic $p$-rational fields. For $p=5$ we prove the existence of infinitely many real quadratic $p$-rational fields.

Benedetto's trick and existence of rational preperiodic structures for quadratic polynomials

We refine a result of R. Benedetto in p-adic analysis in order to exhibit infinitely many quadratic polynomials with rational coefficients having a specified graph of rational preperiodic points.

Isogenies over quadratic fields of elliptic curves with rational $j$-invariant

We determine the possible degrees of cyclic isogenies defined over quadratic fields for non-CM elliptic curves with rational $j$-invariant.

A census of quadratic post-critically finite rational maps defined over Q

We find all quadratic post-critically finite (PCF) rational maps defined over the rationals. We describe an algorithm to search for possibly PCF maps. Using the algorithm, we eliminate all but twelve rational maps, all of which are verifiably PCF. We also give a complete description of possible rational preperiodic structures for quadratic PCF maps defined over Q.

Fibonacci-Lucas zeta 和的消去轮廓

Cancellation profiles of Fibonacci-Lucas zeta sums

研究Fibonacci-Lucas zeta和的项量级分布，证明归一化绝对项和的指数展开及收敛性，并确定最大项索引与条件数增长。

用二次域上的广义二次型表示有理整数

Representing rational integers by generalized quadratic forms over quadratic fields

研究二次域上值域为有理整数的广义二次型，证明实二次域中存在正定二元广义二次型可表示所有正整数，并证明仅有有限多个二次域存在三元广义二次型具有此类性质。

Multi-quadratic $p$-rational Number Fields

For each odd prime $p$, we prove the existence of infinitely many real quadratic fields which are $p$-rational. Explicit imaginary and real bi-quadratic $p$-rational fields are also given for each prime $p$. Using a recent method developed by Greenberg, we deduce the existence of Galois extensions of $\mathbf{Q}$ with Galois group isomorphic to an open subgroup of $GL_n(\mathbf{Z_p})$, for $n =4$ and $n =5$ and at least for all the primes $p <192.699.943$.

Average rank of quadratic twists with a rational point of almost minimal height

Given a family of quadratic twists of a fixed elliptic curve defined over $\mathbb{Q}$, we investigate the average rank in the subfamily of twists having a nontorsion rational point of almost minimal height. We show in particular that the average analytic rank is greater than one.

Bertrand's and Rodriguez Villegas' conjecture for real multi-quadratic Galois extensions of the rationals

The conjecture due to Bertrand and Rodriguez Villegas asserts that the 1-norm of the nonzero element in an exterior power of the units of a number field has a certain lower bound. We prove this conjecture for the exterior square case when the number field is a real multi-quadratic Galois extension of any degree of the rationals.

Diophantine equations defined by binary quadratic forms over rational function fields

We study the ``imaginary" binary quadratic form equations ax^2+bxy+cy^2+g=0 over k[t] in rational function fields, showing that a condition with respect to the Artin reciprocity map, is the only obstruction to the local-global principle for integral solutions of the equation.

On the number of quadratic twists with a rational point of almost minimal height

We investigate the number of curves having a rational point of almost minimal height in the family of quadratic twists of a given elliptic curve. This problem takes its origin in the work of Hooley, who asked this question in the setting of real quadratic fields. In particular, he showed an asymptotic estimate for the number of such fields with almost minimal fundamental unit. Our main result establishes the analogue asymptotic formula in the setting of quadratic twists of a fixed elliptic curve.

Effective simultaneous rational approximation to pairs of real quadratic numbers

Let $ξ, ζ$ be quadratic real numbers in distinct quadratic fields. We establish the existence of effectively computable, positive real numbers $τ$ and $c$, such that, for every integer $q$ with $q > c$ we have $$ \max\{\|q ξ\|, \|q ζ\| \} > q^{-1 + τ}, $$ where $\| \cdot \|$ denotes the distance to the nearest integer.

On a theorem of Bertolini-Darmon about rationality of Stark-Heegner points over genus fields of real quadratic fields

In this paper, we remove certain hypothesis in the theorem of Bertolini-Darmon on the rationality of Stark-Heegner points over narrow genus class fields of real quadratic fields. Along the way, we establish that certain normalized special values of $L$-functions are squares of rational numbers, a result that is of independent interest, and can be regarded as instances of the rank zero case of the Birch and Swinnerton-dyer conjecture modulo squares.

Evenly Divisible Rational Approximations of Quadratic Irrationalities

In a recent paper of Blomer, Bourgain, Radziwiłł and Rudnick, the authors proved the existence of small gaps between eigenvalues of the Laplacian in a rectangular billiard with sides $π$ and $π/\sqrtα$, i.e. numbers of the form $αm^2+ n^2$, whenever $α$ is a quadratic irrationality of certain types. In this note, we extend their results to all positive quadratic irrationalities $α$.

On the l.c.m. of shifted Fibonacci numbers

Let $(F_n)_{n \geq 1}$ be the sequence of Fibonacci numbers. Guy and Matiyasevich proved that \begin{equation*} \log \operatorname{lcm} (F_1, F_2, \dots, F_n) \sim \frac{3 \log α}{π^2} \cdot n^2 \quad \text{as } n \to +\infty, \end{equation*} where $\operatorname{lcm}$ is the least common multiple and $α:= \big(1 + \sqrt{5}) / 2$ is the golden ratio. We prove that for every periodic sequence $\mathbf{s} = (s_n)_{n \geq 1}$ in $\{-1,+1\}$ there exists an effectively computable rational number $C_{\mathbf{s}} > 0$ such that \begin{equation*} \log \operatorname{lcm} (F_3 + s_3, F_4 + s_4, \dots, …

Galois uniformity in quadratic dynamics over rational function fields

We prove that the arboreal Galois representation attached to a large class of quadratic polynomials defined over a field of rational functions in characteristic zero has finite index in the full automorphism group of the associated preimage tree. Moreover, we show that the index is bounded, in most cases, independently of the polynomial.

有理整数作为单位之和——二次情况

Rational integers as sums of units -- the quadratic case

本文研究了二次数域中自然数作为k个单位和的渐进行为，解决了Jarden和Narkiewicz在2007年提出的问题。

Fibonacci多项式生成函数取整系数的多项式值

Polynomial values with integer coefficients of the generating functions for Fibonacci polynomials

本文将Fibonacci序列生成函数取整数值的判别结果推广到满足带系数递推关系的Fibonacci多项式，并在$\sqrt d$代入时给出同形式结论。

On the Divisibility of Class Numbers of Cubic Number Fields with Discriminants in a Prescribed Rational Quadratic Class

Let n be an odd number and F an imaginary quadratic field with odd discriminant. We show that there exists infinitely many cubic fields K such that the class number of K is divisible by n and the Galois closure of K contains F.

Height of rational points on quadratic twists of a given elliptic curve

We formulate a conjecture about the distribution of the canonical height of the lowest non-torsion rational point on a quadratic twist of a given elliptic curve, as the twist varies. This conjecture seems to be very deep and we can only prove partial results in this direction.

有限域二次扩张上的置换有理函数

Permutation Rational Functions over Quadratic Extensions of Finite Fields

本文研究有限域二次扩张上的置换有理函数，利用与二次型相关的特征和确定特殊 $q$-二次多项式的零点数，并据此判定给定有理函数是否为置换。

虚二次数域上的三次型与有理三次型对

Cubic forms over imaginary quadratic number fields and pairs of rational cubic forms

该研究拓展Heath-Brown的有理三次型成果，证明14变量以上虚二次数域三次型非平凡表示零，推导得s≥627时有理三次型对有非平凡解，还证明33变量以上有理三次超曲面含有理直线、对应三次型有殆素数解。

On the $p$-rationality of consecutive quadratic fields

In 2016, in the work related to Galois representations, Greenberg conjectured the existence of multi-quadratic $p$-rational number fields of degree $2^{t}$ for any odd prime number $p$ and any integer $t \geq 1$. Using the criteria provided by him to check $p$-rationality for abelian number fields, certain infinite families of quadratic, biquadratic and triquadratic $p$-rational fields have been shown to exist in recent years. In this article, for any integer $k \geq 1$, we build upon the existing work and prove the existence of infinitely many prime numbers $p$ for which the imaginary quadrat…

Explicit Result on Equivalence of Rational Quadratic Forms Avoiding Primes

Given a pair of regular quadratic forms over $\mathbb{Q}$ which are in the same genus and a finite set of primes $P$, we show that there is an effective way to determine a rational equivalence between these two quadratic forms which are integral over every prime in $P$. This answers one of the principal questions posed by Conway and Sloane in their book {\em Sphere packings, lattices and groups}, Grundlehren der Mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences], Vol 290, Springer-Verlag, New York, 1999; page 402.

On the Distribution of 2-Selmer Ranks within Quadratic Twist Families of Elliptic Curves with Partial Rational Two-Torsion

This paper presents a new result concerning the distribution of 2-Selmer ranks in the quadratic twist family of an elliptic curve with a single point of order two that does not have a cyclic 4-isogeny defined over its two-division field. We prove that at least half of all the quadratic twists of such an elliptic curve have arbitrarily large 2-Selmer rank, showing that the distribution of 2-Selmer ranks in the quadratic twist family of such an elliptic curve differs from the distribution of 2-Selmer ranks in the quadratic twist family of an elliptic curve having either no rational two-torsion o…

On quaternion algebras that split over quadratic number fields

Let $d$ and $m$ be two distinct squarefree integers and $\mathcal{O}_K$ the ring of integers of the quadratic field $K=\mathbb{Q}(\sqrt{d})$. Denote by $ H_K(α, m)$ a quaternion algebra over $K$, where $α\in \mathcal{O}_K$. In this paper we give necessary and sufficient conditions for $ H_K(α, m)$ to split over $K$ for some values of $α$, and we obtain a complete characterization of division quaternion algebras $ H_K(α, m)$ over $K$ whenever $α$ and $m$ are two distinct positive prime integers. Examples are given involving prime Fibonacci numbers.

Rational points on quadratic elliptic surfaces

We consider elliptic surfaces whose coefficients are degree $2$ polynomials in a variable $T$. It was recently shown that for infinitely many rational values of $T$ the resulting elliptic curves have rank at least $1$. In this article, we prove that the Mordell-Weil rank of each such elliptic surface is at most $6$ over $\mathbb Q$. In fact, we show that the Mordell-Weil rank of these elliptic surfaces is controlled by the number of zeros of a certain polynomial over $\mathbb Q$.

Rational 6-cycles under iteration of quadratic polynomials

We present a proof, which is conditional on the Birch and Swinnerton-Dyer Conjecture for a specific abelian variety, that there do not exist rational numbers x and c such that x has exact period N = 6 under the iteration x |-> x^2 + c. This extends earlier results by Morton for N = 4 and by Flynn, Poonen and Schaefer for N = 5.

一类二次有理映射族的动力原子 Galois 群

Dynatomic Galois groups for a family of quadratic rational maps

本文研究具有周期 2 临界点的二次有理映射族，并对其第三和第四个动力原子 Galois 群给出显式结构描述。

秩0和小亏格超椭圆曲线上的有理点和孤立二次点

Rational and isolated quadratic points on hyperelliptic curves of rank 0 and small genus

本文提出一种利用Kummer簇上Mordell-Weil群像来计算秩0超椭圆曲线有理点和孤立二次点的方法，并用Magma实现，在大量曲线上验证。

Arithmetic properties of $3$-cycles of quadratic maps over $\mathbb{Q}$

It is shown that $c=-29/16$ is the unique rational number of smallest denominator, and the unique rational number of smallest numerator, for which the map $f_c(x) = x^2+c$ has a rational periodic point of period $3$. Several arithmetic conditions on the set of all such rational numbers $c$ and the rational orbits of $f_c(x)$ are proved. A graph on the numerators of the rational $3$-periodic points of maps $f_c$ is considered which reflects connections between solutions of norm equations from the cubic field of discriminant $-23$.

关于在二次数域中椭圆曲线的 torsion 增长

On the torsion growth in quadratic number fields for elliptic curves defined over the rationals

本文研究了在二次数域中椭圆曲线 torsion 子群的增长问题，通过分析导数与素数之间的关系，揭示了有理数域上椭圆曲线的 torsion 增长特性。

Rationality of Darmon points over genus fields of non-maximal orders

Stark-Heegner points, also known as Darmon points, were introduced by H. Darmon as certain local points on rational elliptic curves, conjecturally defined over abelian extensions of real quadratic fields. The rationality conjecture for these points is only known in the unramified case, namely, when these points are specializations of global points defined over the strict Hilbert class field $H^+_F$ of the real quadratic field $F$ and twisted by (unramified) quadratic characters of $Gal(H_c^+/F)$. We extend these results to the situation of ramified quadratic characters; more precisely, we show…

三次超曲面上的有理直线 II

Rational lines on cubic hypersurfaces II

本文研究了三次超曲面上的有理直线问题，通过引入二次型线性空间和虚二次数域上的三次型结果，将三次超曲面的有理直线存在下界从33降低至29。

Points on Shimura curves rational over imaginary quadratic fields in the non-split case

For an imaginary quadratic field $k$ of class number $>1$, we prove that there are only finitely many isomorphism classes of rational indefinite quaternion division algebras $B$ such that the associated Shimura curve $M^B$ has $k$-rational points. In other words, the main result asserts that there is a finite set $P(k)$ of prime numbers depending on $k$ such that: if there is a prime divisor of the discriminant of $B$ which is not in $P(k)$, then $M^B$ has no $k$-rational points. Moreover, we can take $P(k)$ to satisfy the following: There is an effectively computable constant $C(k)$ depending…

一对对角方程（一个三次、一个二次）的有理解

Rational solutions of pairs of diagonal equations, one cubic and one quadratic

本文通过获得指数和 $αx^3+βx^2$ 的 32/3 阶矩的最优估计，在局部可解性假设下证明变量数超过 10 时一对三次和二次对角方程存在非平凡整数解。

Pre-images of quadratic dynamical systems

For a quadratic endomorphism of the affine line defined over the rationals we consider the problem of bounding the number of rational points that eventually land at a given constant after iteration, called pre-images of the constant. In the article "Uniform Bounds on Pre-Images Under Quadratic Dynamical Systems," it was shown that the number of rational pre-images is bounded as one varies the morphism in a certain one-dimensional family. Explicit values of the constant for pre-images of zero and -1 defined over the rational numbers were addressed in subsequent articles. This article addresses …

具有有理参数和二次无理参数的超几何级数的 $p$-进有界素数的密度公式

Density formulas for $p$-adically bounded primes for hypergeometric series with rational and quadratic irrational parameters

本文研究超几何级数的 $p$-进有界素数密度，将有理参数情形推广至 $_nF_{n-1}$ 并给出精确公式，同时为二次无理参数情形建立下界及条件性精确公式。

Cycles of Quadratic Polynomials and Rational Points on a Genus-Two Curve

It has been conjectured that for $N$ sufficiently large, there are no quadratic polynomials in $\bold Q[z]$ with rational periodic points of period $N$. Morton proved there were none with $N=4$, by showing that the genus~$2$ algebraic curve that classifies periodic points of period~4 is birational to $X_1(16)$, whose rational points had been previously computed. We prove there are none with $N=5$. Here the relevant curve has genus~$14$, but it has a genus~$2$ quotient, whose rational points we compute by performing a~$2$-descent on its Jacobian and applying a refinement of the method of Chabau…

二次域之 $\mathbb{Z}_p$-扩张上有理椭圆曲线的挠

Torsion of Rational Elliptic Curves over the $\mathbb{Z}_p$-Extensions of Quadratic Fields

本文证明对二次域的 $\mathbb{Z}_p$-扩张（$p>5$），有理椭圆曲线的挠子群不增大，并据此分类了可实现的挠子群。

Rational approximation to real points on quadratic hypersurfaces

Let $Z$ be a quadratic hypersurface of $\mathbb{P}^n(\mathbb{R})$ defined over $\mathbb{Q}$ containing points whose coordinates are linearly independent over $\mathbb{Q}$. We show that, among these points, the largest exponent of uniform rational approximation is the inverse $1/ρ$ of an explicit Pisot number $ρ<2$ depending only on $n$ if the Witt index (over $\mathbb{Q}$) of the quadratic form $q$ defining $Z$ is at most $1$, and that it is equal to $1$ otherwise. Furthermore there are points of $Z$ which realize this maximum. They constitute a countably infinite set in the first case, and an…

Lower bounds of the canonical height on quadratic twists of elliptic curves

We compute a lower bound of the canonical height on quadratic twists of certain elliptic curves. Also we show a simple method for constructing families of quadratic twists with an explicit rational point. % from cubic polynomials. Using the above lower bound, we show that the explicit rational point is primitive as an element of the Mordell--Weil group.