The Products of Three Theta Functions and the General Cubic Theta Functions

In this paper we establish two theta function identities with four parameters by the theory of theta functions. Using these identities we introduce common generalizations of Hirschhorn-Garvan-Borwein cubic theta functions, and also re-derive the quintuple product identity, one of Ramanujan＇s identities, Winquist＇s identity and many other interesting identities.

Riemann theta function periodic wave solutions for the variable-coefficient mKdV equation

In this paper, a variable-coefficient modified Korteweg-de Vries （vc-mKdV） equation is considered. Bilinear forms are presented to explicitly construct periodic wave solutions based on a multidimensional Riemann theta function, then the one and two periodic wave solutions are presented~ and it is also shown that the soliton solutions can be reduced from the periodic wave solutions.

A General Theta Function Identity and Modular Equations

In this paper, we establish a general theta function identity. It is a common origin of many theta function identities. From which many classical and new modular equations are derived. All the proofs are elementary.

FURTHER EXTENSIONS OF SOME TRUNCATED HECKE TYPE IDENTITIES

The main purpose of this paper is to generalize the study of the Hecke-Rogers type series,which are the extensions of truncated theorems obtained by Andrews,Merca,Wang and Yee.Our proofs rely heavily on the theory of Bailey pairs.

Representations by Certain Sextenary Quadratic Forms Whose Coefficients Are 1, 2, 3 and 6

Here, we determine formulae, for the numbers of representations of a positive integer by certain sextenary quadratic forms whose coefficients are 1, 2, 3 and 6.

Binary Bell Polynomials,Bilinear Approach to Exact Periodic Wave Solutions of(2+l)-Dimensional Nonlinear Evolution Equations

In the present letter, we get the appropriate bilinear forms of （2 ＋ 1）-dimensional KdV equation, extended （2 ＋ 1）-dimensional shallow water wave equation and （2 ＋ 1）-dimensional Sawada -Kotera equation in a quick and natural manner, namely by appling the binary Bell polynomials. Then the Hirota direct method and Riemann theta function are combined to construct the periodic wave solutions of the three types nonlinear evolution equations. And the corresponding figures of the periodic wave solutions are given. Furthermore, the asymptotic properties of the periodic wave solutions indicate that the soliton solutions can be derived from the periodic wave solutions.

Rational and Periodic Wave Solutions of Two-Dimensional Boussinesq Equation

Two new exact, rational and periodic wave solutions are derived for the two-dimensional Boussinesq equation. For the first solution it is obtained by performing an appropriate limiting procedure on the soliton solutions obtained by Hirota bilinear method. The second one in terms of Riemann theta function is explicitly presented by virtue of Hirota bilinear method and its asymptotic property is also analyzed in detail. Moreover, it is of interest to note that classical soliton solutions can be reduced from the periodic wave solutions.

Direct Approach to Construct the Periodic Wave Solutions for Two Nonlinear Evolution Equations

With symbolic computation, the Hirota method and Riemann theta function are employed to directly construct the periodic wave solutions for the Hirota-Satsuma equation for shallow water waves and Boiti-Leon-Manna- Pempinelli equation. Then, the corresponding figures of the periodic wave solutions are given. Fhrthermore, it is shown that the known soliton solutions can be reduced from the periodic wave solutions.

Quasi-Periodic Waves and Asymptotic Property for Boiti-Leon-Manna-Pempinelli Equation

In this paper,multi-periodic (quasi-periodic) wave solutions are constructed for the Boiti-Leon-Manna-Pempinelli(BLMP) equation by using Hirota bilinear method and Riemann theta function.At the same time,weanalyze in details asymptotic properties of the multi-periodic wave solutions and give their asymptotic relations betweenthe periodic wave solutions and the soliton solutions.

Analytical three-periodic solutions of Korteweg-de Vries-type equations

Based on the direct method of calculating the periodic wave solution proposed by Nakamura,we give an approximate analytical three-periodic solutions of Korteweg-de Vries(KdV)-type equations by perturbation method for the first time.Limit methods have been used to establish the asymptotic relationships between the three-periodic solution separately and another three solutions,the soliton solution,the one-and the two-periodic solutions.Furthermore,it is found that the asymptotic three-soliton solution presents the same repulsive phenomenon as the asymptotic three-soliton solution during the interaction.

On Schwarzian Triangle Functions, Automorphic Forms and a Generalization of Ramanujan’s Triple Differential Equations

Let G be the group of the fractional linear transformations generated by T（τ）=τ ＋ λ, S（τ）=（τ cos π/n ＋ sin π/n）/（-τ sin π/n ＋ cos π/n）;where λ=2（cos π/m ＋ cos π/n）/sin π/n;m, n is a pair of integers with either n ≥ 2, m ≥ 3 or n ≥ 3, m ≥ 2; τ lies in the upper half plane H.A fundamental set of functions f0, fi and f∞ automorphic with respect to G will be constructed from the conformal mapping of the fundamental domain of G. We derive an analogue of Ramanujan＇s triple differential equations associated with the group G and establish the connection of f0, fi and f∞ with a family of hypergeometric functions.

Partition Identities Arising from Theta Function Identities

The authors show that certain theta function identities of Schroeter and Ramanujan imply elegant partition identities.

Theta Function and Hilbert Modular Forms of Half Integral Weight

In this paper a kind of theta function is constructed by means of spherical function. And we also obtain some Hilbert modular forms of half integral weight.

On Triply Periodic Wave Solutions for(2+1)-Dimensional Boussinesq Equation

By employing Hirota bilinear method and Riemann theta functions of genus one,explicit triply periodic wave solutions for the(2+1)-dimensional Boussinesq equation are constructed under the Backlund transformation u =(1 /6)(u0 1) + 2[ln f(x,y,t)] xx,four kinds of triply periodic wave solutions are derived,and their long wave limit are discussed.The properties of one of the solutions are shown in Fig.1.

Arithmetic Properties of Overpartition Triples

Let P-3 （n） be the number of overpartition triples of n. By elementary series manipulations, we establish some congruences for P-3（n） modulo small powers of 2, such as P-3（16n＋14）≡0 （mod 32）, P-3（8n＋7）≡0 （mod 64）.We also find many arithmetic properties for P-3（n） modulo 7, 9 and 11, involving the following infinite families of Ramanujan-type congruences： for any integers α≥1 and n ≥ 0, we have

On Three Differential Equations Associated with Chebyshev Polynomials of Degrees 3,4 and 6

We shall study the differential equation y^l2=Tn（y）-（1-2μ2）;where μ2 is a constant, Tn（x） are the Chebyshev polynomials with n = 3,4,6. The solutions of the differential equations will be expressed explicitly in terms of the Weierstrass elliptic function which can be used to construct theories of elliptic functions based on 2F1 （1/4, 3/4; 1; z）, 2F1 （l/3, 2/3; 1; z）, 2F1 （1/6, 5/6; 1; z） and provide a unified approach to a set of identities of Rmanujan involving these hypergeometric functions.

Bcklund Transformations and Solutions of a Generalized Kadomtsev-Petviashvili Equation

In this paper, the bilinear form of a generalized Kadomtsev-Petviashvili equation is obtained by applying the binary Bell polynomials. The N-soliton solution and one periodic wave solution are presented by use of the Hirota direct method and the Riemann theta function, respectively. And then the asymptotic analysis demonstrates one periodic wave solution can be reduced to one soliton solution. In the end, the bilinear Backlund transformations are derived.

A finite dimensional proof of the Verlinde formula

We prove two recurrence relations among dimensions Dg(r,d,ω):=dim H^0(UC,ω,ΘUC,ω)of spaces of generalized theta functions on the moduli spaces UC,ω.By using these recurrence relations,an explicit formula(the Verlinde formula)of Dg(r,d,ω)is proved(see Theorem 4.3).

Proofs for certain q-trigonometric identities of Gosper

Applying an addition formula of Liu(2007),we deduce certain Jacobi theta function identities.From these results we confirm several q-trigonometric identities con.jectured by Gosper(2001).Another conjectured identity on the constant Πq is also settled.

Global Asymptotics of Orthogonal Polynomials Associated with a Generalized Freud Weight

In this paper, the authors consider the asymptotic behavior of the monic polynomials orthogonal with respect to the weight function w（x） = /x/2αe-（x4＋tx2）, x ∈R, where α is a constant larger than - 1/2 and t is any real number. They consider this problem in three separate cases： （i） c 〉 -2, （ii） c = -2, and （iii） c 〈 -2, where c ：= tN-1/2 is a constant, N = n ＋ a and n is the degree of the polynomial. In the first two cases, the support of the associated equilibrium measure μ is a single interval, whereas in the third case the support of μt consists of two intervals. In each case, globally uniform asymptotic expansions are obtained in several regions. These regions together cover the whole complex plane. The approach is based on a modified version of the steepest descent method for Riemann-Hilbert problems introduced by Deift and Zhou （1993）.