The Borweins' Cubic Theta Function Identity and Some Cubic Modular Identities of Ramanujan

In this paper the author will give new proofs of the Borweins' cubic theta function identity and a related identity relying on the properties of elliptic functions and the technique of comparing constant terms.     

Cubic Identities of Theta Functions

Many remarkable cubic theorems involving theta functions can be found in Ramanujan's Lost Notebook. Using addition formulas, the Jacobi triple product identity and the quintuple product identity, we establish several theorems to prove Ramanujan's cubic identities.     

Cubic Identities for Theta Series in Three Variables

We consider three-variable analogues of the theta series of Borwein and Borwein. We prove various identities involving these theta series including a generalization of the cubic identity of Borwein and Borwein.     

Identities for Certain Products of Theta Functions

We derive general formulas for certain products of theta functions. Several known theta function identities follow immediately from our formulas.     

On the Gosper’s <Emphasis Type=\"Italic\">q</Emphasis>-constant Π<Subscript><Emphasis Type=\"Italic\">q</Emphasis></Subscript>

Gosper introduced the functions sin_qz and cos_qz as q-analogues for the trigonometric functions sin z and cos z respectively. He stated a variety of identities involving these two q-trigonometric functions along with certain constants denoted by ({Pi _{{q^n}}}) (n ∈ N). Gosper noticed that all his formulas on these constants have more than two of the ({Pi _{{q^n}}}). So, it is natural to raise the question of establishing identities involving only two of the ({Pi _{{q^n}}}). In this paper, our main goal is to give examples of such formulas in only two ({Pi _{{q^n}}}).     

Jacobi's Two-Square Theorem and Related Identities

We show that Jacobi's two-square theorem is an almost immediate consequence of a famous identity of his, and draw combinatorial conclusions from two identities of Ramanujan.     

Identities Involving Partial Mock Theta Functions of Order Five

In this paper we have given transformations for the partial mock theta functions of order five and also some identities between these partial mock theta functions analogous to the identities given by Ramanujan.     

应用留数定理计算一类实积分

应用留数定理,通过构造被积函数,将一类实积分的计算问题转化为求留数的计算,得到求此类问题的一种解法.     

Some Theorems on the Rogers-Ramanujan Continued Fraction and Associated Theta Function Identities in Ramanujan's Lost Notebook

In his lost notebook, Ramanujan recorded several modular equations of degree 5 related to the Rogers-Ramanujan continued fraction R(q). We prove several of these identities and give factorizations of some of them in this paper.The parameter k = R(q) R₂(q₂) introduced by Ramanujan in his second notebook has not been recognized for its usefulness. In this work, we demonstrate how beautifully the parameter k works, as we prove several identities involving k stated by Ramanujan in the lost notebook.     

Integrals, partitions and MacMahon's Theorem

In two previous papers, the study of partitions with short sequences has been developed both for its intrinsic interest and for a variety of applications. The object of this paper is to extend that study in various ways. First, the relationship of partitions with no consecutive integers to a theorem of MacMahon and mock theta functions is explored independently. Secondly, we derive in a succinct manner a relevant definite integral related to the asymptotic enumeration of partitions with short sequences. Finally, we provide the generating function for partitions with no sequences of length K and part exceeding N.     

Circular Summation of the 13th Powers of Ramanujan's Theta Function

An explicit formula is derived for the circular summation of the 13th power of Ramanujan's theta function in terms of Dedekind eta function.     

Theta Series of Quaternion Algebras over Function Fields

Let K be the function field over a finite field of odd order, and let H be a definite quaternion algebra over K. If Λ is an order of level M in H, we define theta series for each ideal I of Λ using the reduced norm on H. Using harmonic analysis on the completed algebra H_∞ and the arithmetic of quaternion algebras, we establish a transformation law for these theta series. We also define analogs of the classical Hecke operators and show that in general, the Hecke operators map the theta series to a linear combination of theta series attached to different ideals, a generalization of the classical Eichler Commutation Relation.     

Partial Theta Functions. I. Beyond the Lost Notebook

It is shown how many of the partial theta function identitiesin Ramanujan's lost notebook can be generalized to infinitefamilies of such identities. Key in our construction is theBailey lemma and a new generalization of the Jacobi triple productidentity. By computing residues around the poles of our identitieswe find a surprising connection between partial theta functionidentities and Garrett–Ismail–Stanton-type extensionsof multisum Rogers–Ramanujan identities. 2000 MathematicsSubject Classification 05A30, 33D15, 33D90.     

The Vanishing of the Theta Function in the KP Direction: A Geometric Approach

We give a geometric proof of a formula, due to Segal and Wilson, which describes the order of vanishing of the Riemann theta function in the direction which corresponds to the direction of the tangent space of a Riemann surface at a marked point. While this formula appears in the work of Segal and Wilson as a by-product of some nontrivial constructions from the theory of integrable systems (loop groups, infinite-dimensional Grassmannians, tau functions, Schur polynomials, etc.) our proof only uses the classical theory of linear systems on Riemann surfaces.     

M.P. Appell's Function and Vector Bundles of Rank 2 on Elliptic Curves

This paper is devoted to the function introduced by M.P. Appell in connection with decomposition of elliptic functions of the third kind into simple elements. We show that this function is related to global sections of rank-2 vector bundles on elliptic curves. We derive analogues of theta-identities for this function and prove the divisibility property for the action of the modular group, that should be considered as a replacement of the functional equation.     

On an Arithmetical Function

In this paper we introduce an arithmetical function (n), the difference between the number of divisors of n congruent to 1 mod 3 and those congruent to –1 mod 3. This function then is related to the classical function (n) which is the sum of the divisors of n. In particular we prove the identity

复变函数中刘维尔定理的新证明

利用截断函数的性质给出了复变函数中刘维尔定理的一种新的证明方法.