On Ramanujan's cubic continued fraction and explicit evaluations of theta-functions

偶数阶拉马努金连分数的推广

Generalization of Ramanujan's Continued Fractions for Even Order

该研究借助拉马努金连分数恒等式推导偶数阶广义连分数，建立theta函数恒等式，以76阶连分数为例得到分拆理论恒等式等，推广了拉马努金连分数。

Results on some partition functions arising from certain relations involving the Rogers-Ramanujan continued fractions

Relations involving the Rogers-Ramanujan continued fractions $R(q),$ $R(q^3 ),$ and $R(q^4)$ are used to find new generating functions and congruences modulo 5 and 25 for 3-core, 4-core, 4-regular, and colored partition functions.

Convergence properties of the classical and generalized Rogers-Ramanujan continued fraction

The aim of this paper is to study the convergence and divergence of the Rogers-Ramanujan and the generalized Rogers-Ramanujan continued fractions on the unit circle. We provide an example of an uncountable set of measure zero on which the Rogers-Ramanujan continued fraction $R(x)$ diverges and which enlarges a set previously found by Bowman and Mc Laughlin. We further study the generalized Rogers-Ramanujan continued fractions $R_a(x)$ for roots of unity $a$ and give explicit convergence and divergence conditions. As such, we extend some work of Huang towards a question originally investigated …

On series identities of Gosper and integrals of Ramanujan theta function $ψ(q)$

We prove some Lambert series which were stated by Gosper without proof or reference. As an application, we shall evaluate integrals involving Ramanujan theta function $ψ(q)$. Furthermore, motivated by Ramanujan's identities for $qψ^4(q^2)$ and $\fr{ψ^3(q)}{ψ(q^3)}$, we shall evaluate the squares of $qψ^4(q^2)$ and $\fr{ψ^3(q)}{ψ(q^3)}$ in terms of Lambert series.

On certain explicit congruences for mock theta functions

Recently, Garthwaite-Penniston have shown that the coefficients of Ramanujan's mock theta function $ω$ satisfy infinitely many congruences of Ramanujan-type. In this work we give the first explicit examples of congruences for Ramanujan's mock theta function $ω$ and another mock theta function $\mathcal{C}$.

Completions and algebraic formulas for the coefficients of Ramanujan's mock theta functions

We present completions of mock theta functions to harmonic weak Maass forms of weight $1/2$ and algebraic formulas for the coefficients of mock theta functions. We give several harmonic weak Maass forms of weight $1/2$ that have mock theta functions as their holomorphic part. Using these harmonic weak Maass forms and the Millson theta lift we compute finite algebraic formulas for the coefficients of the appearing mock theta functions in terms of traces of singular moduli.

关于拉马努金阶数五、十和二十的连分数及相关Lambert级数恒等式

On Ramanujan's Continued Fractions of Orders Five, Ten, and Twenty and Associated Lambert Series Identities

本文利用Jacobi theta函数、模拟theta函数及Ramanujan求和公式，建立了阶数二十的拉马努金连分数与阶数十、Rogers-Ramanujan连分数的新恒等式，并推导了Lambert级数与theta函数的关系，扩展了先前工作。

Ramanujan的十四阶和二十八阶q-连分数及消失系数的若干恒等式

Some Identities of Ramanujan's q-Continued Fractions of Order Fourteen and Twenty-Eight, and Vanishing Coefficients

本文从Ramanujan的一般连分数恒等式推导出十四阶和二十八阶连分数，建立theta函数恒等式，并推导色分区恒等式及消失系数结果。

Ramanujan's type of product of theta functions and its applications

In this paper, we initiate a generous amount of new-found general theorems for explicit evaluations of product of the theta functions $b_{m, n}$ using Kronecker's limit formula and other various novel explicit evaluations that were introduced thereupon. Also, we have obtained a few novel values of Ramanujan's class invariant $g_n$ using new-found values of $b_{m, n}$. Eventually, we have shown that $b_{m, n}$ is the unit in certain algebraic number fields.

Ramanujan and the Regular Continued Fraction Expansion of Real Numbers

In some recent papers, the authors considered regular continued fractions of the form \[ [a_{0};\underbrace{a,...,a}_{m}, \underbrace{a^{2},...,a^{2}}_{m}, \underbrace{a^{3},...,a^{3}}_{m}, ... ], \] where $a_{0} \geq 0$, $a \geq 2$ and $m \geq 1$ are integers. The limits of such continued fractions, for general $a$ and in the cases $m=1$ and $m=2$, were given as ratios of certain infinite series. However, these formulae can be derived from known facts about two continued fractions of Ramanujan. Motivated by these observations, we give alternative proofs of the results of the previous authors …

Continued Fraction Proofs of $m$-versions of Some Identities of Rogers-Ramanujan-Slater Type

We derive two general transformations for certain basic hypergeometric series from the recurrence formulae for the partial numerators and denominators of two $q$-continued fractions previously investigated by the authors. By then specializing certain free parameters in these transformations, and employing various identities of Rogers-Ramanujan type, we derive \emph{$m$-versions} of these identities. Some of the identities thus found are new, and some have been derived previously by other authors, using different methods. By applying certain transformations due to Watson, Heine and Ramanujan, w…

Periodic points of algebraic functions related to a continued fraction of Ramanujan

A continued fraction $v(τ)$ of Ramanujan is evaluated at certain arguments in the field $K = \mathbb{Q}(\sqrt{-d})$, with $-d \equiv 1$ (mod $8$), in which the ideal $(2) = \wp_2 \wp_2'$ is a product of two prime ideals. These values of $v(τ)$ are shown to generate the inertia field of $\wp_2$ or $\wp_2'$ in an extended ring class field over the field $K$. The conjugates over $\mathbb{Q}$ of these same values, together with $0, -1 \pm \sqrt{2}$, are shown to form the exact set of periodic points of a fixed algebraic function $\hat F(x)$, independent of $d$. These are analogues of similar resul…

八阶仿θ函数$V_{0}(q)$的拉马努金型恒等式的简短证明

Short proofs of Ramanujan-like identities for the eighth order mock theta function $V_{0}(q)$

该研究利用Appell函数性质给出八阶仿θ函数$V_0(q)$的拉马努金型恒等式的简短证明，并参照相关经典结果提出恒等式的推广形式。

The explicit evaluations of Ramanujan's remarkable product of theta-functions a_{m, n}

On pages 338 and 339 in his first notebook, Ramanujan defined the remarkable product of theta-functions $a_{m, n}$. Also he recorded eighteen explicit values depending on two parameters, namely, $m$, and $n$, where these are odd integers. All these values were established by Berndt et al. In this paper, we initiate to study explicit evaluations of $a_{m, n}$ for even values of $m$. We establish a new general theorems for the explicit evaluations of $a_{m, n}$ involving class invariant of Ramanujan. For this purpose, we establish several new P-Q mixed modular equations. Using these theorems, we…

关于拉马努金的三十四阶和六十八阶 $q$-连分数

On Ramanujan's $q$-Continued Fractions of Order Thirty-Four and Sixty-Eight

本文从拉马努金的一般连分数恒等式推导出三十四阶和六十八阶的 $q$-连分数，建立了相关的 theta 函数恒等式，并研究了这些连分数及其倒数的消失系数，最后应用 theta 函数恒等式导出了有色分拆恒等式。

论拉马努金遗失的笔记本及二阶、六阶和八阶仿theta函数的新类十阶恒等式

On Ramanujan's lost notebook and new tenth-order like identities for second-, sixth-, and eighth-order mock theta functions

该研究依托拉马努金遗失的笔记本，借助Hickerson和Mortenson的Appell函数性质，发现并证明了3个六阶仿theta函数的类十阶新恒等式，还补充了19个不同阶仿theta函数组合的类十阶恒等式。

Some extensions for Ramanujan's circular summation formula

In this paper, we give some extensions for Ramanujan's circular summation formula with the mixed products of two Jacobi's theta functions. As some applications, we also obtain many interesting identities of Jacobi's theta functions.

关于涉及拉马努金theta函数的新参数

On a new parameter involving Ramanujan's theta-functions

本文定义了一个涉及拉马努金theta函数的新参数，并利用其与已知参数的模关系求出显式值，进而建立显式计算含 $φ(q)$ 的theta函数之比的一般定理。

Solutions of diophantine equations as periodic points of $p$-adic algebraic functions, II: The Rogers-Ramanujan continued fraction

In this part we show that the diophantine equation $X^5+Y^5=\varepsilon^5(1-X^5Y^5)$, where $\varepsilon=\frac{-1+\sqrt{5}}{2}$, has solutions in specific abelian extensions of quadratic fields $K=\mathbb{Q}(\sqrt{-d})$ in which $-d \equiv \pm 1$ (mod $5$). The coordinates of these solutions are values of the Rogers-Ramanujan continued fraction $r(τ)$, and are shown to be periodic points of an algebraic function.

Partitions associated with the Ramanujan/Watson mock theta functions $ω(q), ν(q)$ and $ϕ(q)$

The generating function of partitions with repeated (resp. distinct) parts such that each odd part is less than twice the smallest part is shown to be the third order mock theta function $ω(q)$ (resp. $ν(-q)$). Similar results for partitions with the corresponding restriction on each even part are also obtained, one of which involves the third order mock theta function $ϕ(q)$. Congruences for the smallest parts functions associated to such partitions are obtained. Two analogues of the partition-theoretic interpretation of Euler's pentagonal theorem are also obtained.

Ramanujan's $q$-continued fractions

Ramanujan's $q$-continued fractions are a central part of Ramanujan's development of basic hypergeometric series. They appear in Chapter 16 of Part III and Chapter 32 of Part V of {\em Ramanujan's Notebooks} edited by Berndt, and in Volume I of Andrews and Berndt's {\em Ramanujan's Lost Notebook}. In these references the continued fractions as presented in the order in which they appear in Ramanujan's original notebooks. We summarize the work of several authors on this topic and re-organize Ramanujan's $q$-continued fractions.

拉马努金伪θ函数系数的超越公式

Transcendental formulas for the coefficients of Ramanujan's mock theta functions

本研究证明了拉马努金最后一封信中全部17个伪θ函数的精确系数公式，同时给出了奇秩格相伴韦伊表示的克洛斯特曼和之和的界定理，推进了伪θ函数系数的精确表达研究。

On the irrationality of Ramanujan's mock theta functions and other q-series at an infinite number of points

We show that all of Ramanujan's mock theta functions of order 3, Watson's three additional mock theta functions of order 3, the Rogers-Ramanujan q-series, and 6 mock theta functions of order 5 take on irrational values at the points q=\pm 1/2,\pm 1/3,\pm 1/4,...

Partition Identities for Ramanujan's Third Order Mock Theta Functions

We find two involutions on partitions that lead to partition identities for Ramanujan's third order mock theta functions $ϕ(-q)$ and $ψ(-q)$. We also give an involution for Fine's partition identity on the mock theta function f(q). The two classical identities of Ramanujan on third order mock theta functions are consequences of these partition identities. Our combinatorial constructions also apply to Andrews' generalizations of Ramanujan's identities.

Bilateral series and Ramanujan's radial limits

Ramanujan's last letter to Hardy explored the asymptotic properties of modular forms, as well as those of certain interesting $q$-series which he called \emph{mock theta functions}. For his mock theta function $f(q)$, he claimed that as $q$ approaches an even order $2k$ root of unity $ζ$, \[\lim_{q\to ζ} \big(f(q) - (-1)^k (1-q)(1-q^3)(1-q^5)\cdots (1-2q + 2q^4 - \cdots)\big) = O(1),\] and hinted at the existence of similar statements for his other mock theta functions. Recent work of Folsom-Ono-Rhoades provides a closed formula for the implied constant in this radial limit of $f(q)$. Here, by…

Ramanujan and Extensions and Contractions of Continued Fractions

If a continued fraction $K_{n=1}^{\infty} a_{n}/b_{n}$ is known to converge but its limit is not easy to determine, it may be easier to use an extension of $K_{n=1}^{\infty}a_{n}/b_{n}$ to find the limit. By an extension of $K_{n=1}^{\infty} a_{n}/b_{n}$ we mean a continued fraction $K_{n=1}^{\infty} c_{n}/d_{n}$ whose odd or even part is $K_{n=1}^{\infty} a_{n}/b_{n}$. One can then possibly find the limit in one of three ways: (i) Prove the extension converges and find its limit; (ii) Prove the extension converges and find the limit of the other contraction (for example, the odd part, if $K_{…

Vanishing coefficients in several $q$-series expansions related to the Rogers--Ramanujan continued fraction

In this paper, we investigate several infinite products with vanishing Taylor coefficients in arihmetic progressions. These infinite products are closely related to the Rogers--Ramanujan continued fraction. Moreover, a handful of new identities involving Ramanujan's parameters will be established.

Applications of the Heine and Bauer-Muir transformations to Rogers-Ramanujan type continued fractions

In this paper we show that various continued fractions for the quotient of general Ramanujan functions $G(aq,b,łq)/G(a,b,ł)$ may be derived from each other via Bauer-Muir transformations. The separate convergence of numerators and denominators play a key part in showing that the continued fractions and their Bauer-Muir transformations converge to the same limit. We also show that these continued fractions may be derived from Heine's continued fraction for a ratio of $_2ϕ_1$ functions and other continued fractions of a similar type, and by this method derive a new continued fraction for $G(aq,b…

Rogers–Ramanujan 连分数与 $\mathbf{2π}$ 的逼近

Rogers-Ramanujan continued fraction and approximations to $\mathbf{2π}$

本文利用 Rogers–Ramanujan 连分数与 Ramanujan、Rogers 的模方程构造 $2π$ 的高速递归逼近，分别实现正确位数五倍和十一倍增长。

A $q$-continued fraction

We use the method of generating functions to find the limit of a $q$-continued fraction, with 4 parameters, as a ratio of certain $q$-series. We then use this result to give new proofs of several known continued fraction identities, including Ramanujan's continued fraction expansions for $(q^2;q^3)_{\infty}/(q;q^3)_{\infty}$ and $(q;q^2)_\infty / (q^{3};q^{6})_\infty^3$. In addition, we give a new proof of the famous Rogers-Ramanujan identities. We also use our main result to derive two generalizations of another continued fraction due to Ramanujan.

关于涉及Rogers-Ramanujan连分数的某些无穷乘积符号模式周期性的若干猜想的讨论

Discussion on some conjectures regarding the periodicity of sign patterns of certain infinite products involving the Rogers-Ramanujan Continued Fractions

本文讨论了涉及Rogers-Ramanujan连分数的无穷级数系数符号模式的猜想，通过证明Baruah和Sarma提出的关于$A(5n)$和$B(5n)$符号模式的猜想在$n=0$时不成立，指出了原猜想的局限性。

关于拉马努金θ函数之间同重数的存在性

On the occurrence of congruence multiplicities between Ramanujan's theta functions

本研究证明了拉马努金θ函数φ(-q)与ψ(q)相关无穷级数的八类模3、5任意次幂的同余关系，明确二者同余族的同构性并预测额外同构的存在。

Ramanujan七次θ函数恒等式的三次和五次类似

Cubic and quintic analogues of Ramanujan's septic theta function identity

受Ramanujan七次θ函数恒等式补全的启发，本文提出三次和五次类似，并结合Ramanujan类不变量，为其著名θ函数φ(q)提供了多种求值。

Holomorphic projections and Ramanujan's mock theta functions

We employ spectral methods of automorphic forms to establish a holomorphic projection operator for tensor products of vector-valued harmonic weak Maass forms and vector-valued modular forms. We apply this operator to discover simple recursions for Fourier series coefficients of Ramanujan's mock theta functions.

Modular Transformations of Ramanujan's Tenth Order Mock Theta Functions

The modular transformations of Ramanujan's tenth order mock theta functions are computed, beginning from Choi's Hecke-type identites and using Zwegers' results on indefinite theta series. Explicit completions and shadows are found as an intermediate step. Our result for the modular transformations confirms numerical work by Gordon and McIntosh, and a recent conjecture by Cheng, Duncan, and Harvey.

Ramanujan's theta functions and sums of triangular numbers

Let $\Bbb Z$ and $\Bbb N$ be the set of integers and the set of positive integers, respectively. For $a_1,a_2,\ldots,a_k,n\in\Bbb N$ let $N(a_1,a_2,\ldots,a_k;n)$ be the number of representations of $n$ by $a_1x_1^2+a_2x_2^2+\cdots+a_kx_k^2$, and let $t(a_1,a_2,\ldots,a_k;n)$ be the number of representations of $n$ by $a_1\frac{x_1(x_1-1)}2+a_2\frac{x_2(x_2-1)}2+\cdots+a_k\frac{x_k(x_k-1)}2$ $(x_1,\ldots,x_k\in\Bbb Z$). In this paper, by using Ramanujan's theta functions $φ(q)$ and $ψ(q)$ we reveal many relations between $t(a_1,a_2,\ldots,a_k;n)$ and $N(a_1,a_2,\ldots,a_k;8n+a_1+\cdots+a_k)$ f…

On the Divergence of the Rogers-Ramanujan Continued Fraction on the Unit Circle

Let the continued fraction expansion of any irrational number $t \in (0,1)$ be denoted by $[0,a_{1}(t),a_{2}(t),...]$ and let the i-th convergent of this continued fraction expansion be denoted by $c_{i}(t)/d_{i}(t)$. Let \[ S=\{t \in (0,1): a_{i+1}(t) \geq ϕ^{d_{i}(t)} \text{infinitely often}\}, \] where $ϕ= (\sqrt{5}+1)/2$. Let $Y_{S} =\{\exp(2 πi t): t \in S \}$. It is shown that if $y \in Y_{S}$ then the Rogers-Ramanujan continued fraction, R(y), diverges at y. S is an uncountable set of measure zero. It is also shown that there is an uncountable set of points, $G \subset Y_{S}$, such that…

拉马努金初等连分数的初等处理

An elementary treatment of Ramanujan's elementary continued fractions

本文研究拉马努金第二笔记本第12章中的初等连分数，这些连分数是其超几何与$q$-超几何连分数的前身，并给出初等处理。

关于 Ramanujan 的三次连分数

On Ramanujan's cubic continued fraction

本文证明了由特定代数方程定义的周期点可用 Ramanujan 三次连分数表示，并揭示了其在虚二次域中生成特定环类域的代数性质。

How to prove Ramanujan's $q$-continued fractions

By using Euler's approach of using Euclid's algorithm to expand a power series into a continued fraction, we show how to derive Ramanujan's $q$-continued fractions in a systematic manner.

Ramanujan函数$k(τ)$对于六阶连分数$X(τ)$的类比

Analogue of Ramanujan's function $k(τ)$ for the continued fraction $X(τ)$ of order six

本研究受Park工作启发，利用Lee和Park方法，证明了六阶连分数$X(τ)$的类比函数$w(τ)=X(τ)X(3τ)$可表示为$Γ_0(18)$上模函数域的归一化生成元$u(τ)$，并推导了其模方程及$j$-不变量的表达式。

Rogers-Ramanujan连分数的对数矩与奇数zeta值

Logarithmic moments of the Rogers-Ramanujan continued fraction and odd zeta values

该研究探讨Rogers-Ramanujan连分数的尖点展开对其普通与对数Mellin矩的控制作用，证明相关系数的代数性质，确定归一化矩生成函数的极点，并建立反射恒等式等结果。

二十面体方程在Rogers-Ramanujan连分数中的应用

Applications of the icosahedral equation for the Rogers-Ramanujan continued fraction

本文利用二十面体方程和模关系，通过Wolfram语言的RootApproximant命令，系统发现并证明了Rogers-Ramanujan连分数在特定指数处的根式闭式表达式，包括一个计算上困难的$R(e^{-\pi\sqrt{48/5}})$值。

The Convergence Behavior of $q$-Continued Fractions on the Unit Circle

In a previous paper, we showed the existence of an uncountable set of points on the unit circle at which the Rogers-Ramanujan continued fraction does not converge to a finite value. In this present paper, we generalise this result to a wider class of $q$-continued fractions, a class which includes the Rogers-Ramanujan continued fraction and the three Ramanujan-Selberg continued fractions. We show, for each $q$-continued fraction, $G(q)$, in this class, that there is an uncountable set of points, $Y_{G}$, on the unit circle such that if $y \in Y_{G}$ then $G(y)$ does not converge to a finite va…

Ramanujan's radial limits and mixed mock modular bilateral $q$-hypergeometric series

Using results from Ramanujan's lost notebook, Zudilin recently gave an insightful proof of a radial limit result of Folsom, Ono, and Rhoades for mock theta functions. Here we see that the author's previous work on the dual nature of Appell--Lerch sums and partial theta functions and on constructing bilateral $q$-series with mixed mock modular behaviour is well-suited for such radial limits. We present five more radial limit results which follow from mixed mock modular bilateral $q$-hypergeometric series. We also obtain the mixed mock modular bilateral series for a universal mock theta function…

二次型、精确覆盖系统与Theta函数的乘积恒等式

Quadratic Forms, Exact Covering Systems, and Product Identities for Theta Functions

本文建立整二次型与精确覆盖系统的联系，提出结构框架生成无穷多涉及拉马努金theta函数的乘积恒等式，统一解释二十二个Rogers-Ramanujan恒等式，并推导三元二次型相关新恒等式。

A bijective proof of a false theta function identity from Ramanujan's lost notebook

In his lost notebook, Ramanujan listed 5 identities related to the false theta function $$f(q)=\sum_{n=0}^\infty (-1)^nq^{n(n+1)/2}.$$ A new combinatorial interpretation and proof of one of these identities is given. The methods of the proof allow for new multivariate generalizations of this identity. Additionally, the same technique can be used to obtained a combinatorial interpretation of another one of the identities.

Wronskians of theta functions and series for $1/π$

In this article, we define functions analogous to Ramanujan's function $f(n)$ defined in his famous paper "Modular equations and approximations to $π$". We then use these new functions to study Ramanujan's series for $1/π$ associated with the classical, cubic and quartic bases.

Ramanujan七次θ函数恒等式的九次类似

Ninth degree analogue of Ramanujan's septic theta function identity

本文提出了Ramanujan七次θ函数恒等式的九次类似，并应用其笔记簿中的三次方程条目、用θ函数解释三角恒等式，最后计算了五个φ(e^{-π√n})的例子。

Automatic Proof of Theta-Function Identities

This is a tutorial for using two new MAPLE packages, thetaids and ramarobinsids. The thetaids package is designed for proving generalized eta-product identities using the valence formula for modular functions. We show how this package can be used to find theta-function identities as well as prove them. As an application, we show how to find and prove Ramanujan's 40 identities for his so called Rogers-Ramanujan functions G(q) and H(q). In his thesis Robins found similar identities for higher level generalized eta-products. Our ramarobinsids package is for finding and proving identities for gene…

用θ函数的单商表示拆分Appell函数

Splitting Appell functions in terms of single quotients of theta functions

围绕拉马努金仿θ函数的恒等式研究，本文提出了若干族适用于其构建基块Appell函数的类十阶恒等式，拓展了仿θ函数恒等式的研究范畴。

Product formulas for the $5$-division points on the Tate normal form and the Rogers-Ramanujan continued fraction

Explicit formulas are proved for the $5$-torsion points on the Tate normal form $E_5$ of an elliptic curve having $(X,Y)=(0,0)$ as a point of order $5$. These formulas express the coordinates of points in $E_5[5] - \langle(0,0)\rangle$ as products of linear fractional quantities in terms of $5$-th roots of unity and a parameter $u$, where the parameter $b$ which defines the curve $E_5$ is given as $b=(\varepsilon^5 u^5- \varepsilon^{-5})/(u^5+1)$ and $\varepsilon = (-1+\sqrt{5})/2$. If $r(τ)$ is the Rogers-Ramanujan continued fraction and $b=r^5(τ)$, then the coordinates of points of order $5$…

通过Ramanujan theta函数乘积研究涉及广义3-、4-、5-和8-角数的通用四元混合和

Universal quaternary mixed sums involving generalized 3-, 4-, 5- and 8-gonal numbers via products of Ramanujan's theta functions

本文利用Ramanujan theta函数恒等式理论，系统确定了由广义3-、4-、5-和8-角数构成的四元混合和何时能表示所有非负整数，即其通用性。

On the Divergence in the General Sense of $q$-Continued Fraction on the Unit Circle

We show, for each $q$-continued fraction $G(q)$ in a certain class of continued fractions, that there is an uncountable set of points on the unit circle at which $G(q)$ diverges in the general sense. This class includes the Rogers-Ramanujan continued fraction and the three Ramanujan-Selberg continued fraction. We discuss the implications of our theorems for the general convergence of other $q$-continued fractions, for example the Göllnitz-Gordon continued fraction, on the unit circle.