Journal of Nonlinear Mathematical Physics

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1487 articles
Research Article

On Pauli graded contractions of sl(3, C)

Miloslav Havlicek, Jiri Patera, Edita Pelantova, Jiri Tolar
Pages: 37 - 42
We consider a special fine grading of sl(3, C), where the grading subspaces are geerated by 3 × 3 generalized Pauli matrices. This fine grading decomposes sl(3, C) into eight one­dimensional subspaces. Our aim is to find all contractions of sl(3, C) which preserve this grading. We have found that the...
Research Article

SO(2) and Hamilton-Dirac mechanics

Cestmir Burdik, Eugen Paal, Juri Virkepu
Pages: 37 - 43
Canonical formalism for plane rotations is developed. This group can be seen as a toy model of the Hamilton-Dirac mechanics with constraints. The Lagrangian and Hamiltonian are explicitly constructed and their physical interpretation are given. The Euler-Lagrange and Hamiltonian canonical equations coincide...
Research Article

Fractal and Chaotic Solutions of the Discrete Nonlinear Schrödinger Equation in Classical and Quantum Systems

H.S. Dhillon, F.V. Kusmartsev, K.E. Kürten
Pages: 38 - 49
We discuss stationary solutions of the discrete nonlinear Schrödinger equation (DNSE) with a potential of the 4 type which is generically applicable to several quantum spin, electron and classical lattice systems. We show that there may arise chaotic spatial structures in the form of incommensurate or...
Research Article

High-Frequency Asymptotics for the Helmholtz Equation in a Half-Plane

Min-Hai Huang
Pages: 38 - 47
Base on the integral representations of the solution being derived via Fokas' transform method, the high-frequency asymptotics for the solution of the Helmholtz equation, in a half-plane and subject to the Neumann condition is discussed. For the case of piecewise constant boundary data, full asymptotic...
Research Article

On Asymptotic Methods in the Theory of Differential Equations of Mathematical Physics

Mykola Shkil
Pages: 40 - 50
In 1807 Fourier suggested a original method of solving partial differential equations. The method is known to lead to ordinary differential equations containing some arbitrary parameter...
Research Article

Progressive Internal Gravity Waves With Bounded Upper Surface Climbing a Triangular Obstacle

Mina B. Abd-El-Malek, Malak N. Makar
Pages: 41 - 53
In this paper we discuss a theoretical model for the interfacial profiles of progressive non-linear waves which result from introducing a triangular obstacle, of finite height, attached to the bottom below the flow of a stratified, ideal, two layer fluid, bounded from above by a rigid boundary. The derived...
Research Article

Symmetries, Lagrangian Formalism and Integration of Second Order Ordinary Difference Equations

Vladimir Dorodnitsyn, Roman Kozlov, Pavel Winternitz
Pages: 41 - 56
An integration technique for difference schemes possessing Lie point symmetries is proposed. The method consists of determining an invariant Lagrangian and using a discrete version of Noether's theorem to obtain first integrals. This lowers the order of the invariant difference scheme.
Research Article

Poisson brackets, Novikov-Leibniz structures and integrable Riemann hydrodynamic systems

Orest D. Artemovych, Denis Blackmore, Anatolij K. Prykarpatski
Pages: 41 - 72
A general differential-algebraic approach is devised for constructing multi-component Hamiltonian operators as differentiations on suitably constructed loop Lie algebras. The related Novikov-Leibniz algebraic structures are presented and a new non-associative “Riemann” algebra is constructed, which is...
Research Article

On Weak Convergence of Locally Periodic Functions

Dag Lukkassen, Peter Wall
Pages: 42 - 57
We prove a generalization of the fact that periodic functions converge weakly to the mean value as the oscillation increases. Some convergence questions connected to locally periodic nonlinear boandary value problems are also considered.
Research Article

Sp(2) Quantization of Solitonic Theories

V. Calian
Pages: 42 - 47
The gauge-field theoretical formulation of solitonic theories is quantized by using an extended version of the BRST Sp(2) symmetric formalism. The proposed method is based on a modified triplectic geometry which allows us to incorporate the linear and/or nonlinear global symmetries of the model and to...
Research Article

Superintegrable Anharmonic Oscillators on N-dimensional Curved Spaces

Angel Ballesteros, Alberto Enciso, Francisco José Herranz, Orlando Ragnisco
Pages: 43 - 52
The maximal superintegrability of the intrinsic harmonic oscillator potential on N-dimensional spaces with constant curvature is revisited from the point of view of sl(2)-Poisson coalgebra symmetry. It is shown how this algebraic approach leads to a straightforward definition of a new large family of...
Research Article

An Explicit Solution for Deep Water Waves With Coriolis Effects

Anca-Voichita Matioc
Pages: 43 - 50
We present an explicit solution for the geophysical equatorial deep water waves in the f-plane approximation.
Research Article

Symmetries of Hamiltonian Equations and Λ-Constants of Motion

Giampaolo Cicogna
Pages: 43 - 60
We consider symmetries and perturbed symmetries of canonical Hamiltonian equations of motion. Specifically we consider the case in which the Hamiltonian equations exhibit a Λ-symmetry under some Lie point vector field. After a brief survey of the relationships between standard symmetries and the existence...
Research Article

On Poisson Realizations of Transitive Lie Algebroids

Yuri Vorobiev
Pages: 43 - 48
We show that every transitive Lie algebroid over a connected symplectic manifold comes from an intrinsic Lie algebroid of a symplectic leaf of a certain Poisson structure. The reconstruction of the corresponding Poisson structures from the Lie algebroid is given in terms of coupling tensors.
Research Article

Singular Scattering Matrices

David Atkinson
Pages: 43 - 49
A nonlinear integrodifferential equation is solved by the methods of S-matrix theory. The technique is shown to be applicable to situations in which the effective potential is singular.
Research Article

Revisiting Noether's Theorem on constants of motion

Gianluca Gorni, Gaetano Zampieri
Pages: 43 - 73
In this paper we revisit Noether's theorem on the constants of motion for Lagrangian mechanical systems in the ODE case, with some new perspectives on both the theoretical and the applied side. We make full use of invariance up to a divergence, or, as we call it here, Bessel-Hagen (BH) invariance....
Research Article

A Formal Approach for Handling Lie Point Symmetries of Scalar First-Order Ito Stochastic Ordinary Differential Equations

Ebrahim Fredericks, Fazal M Mahomed
Pages: 44 - 59
Many methods of deriving Lie point symmetries for Itˆo stochastic ordinary differential equations (SODEs) have surfaced. In the Itˆo calculus context both the formal and intuitive understanding of how to construct these symmetries has led to seemingly disparate results. The impact of Lie point symmetries...
Research Article

On New Galilei- and Poincare-Invariant Nonlinear Equations for Electromagnetic Field

Wilhelm Fushchych, Ivan Tsyfra
Pages: 44 - 48
Nonlinear systems of differential equations for E and H which are compatible with the Galilei relativity principle are proposed. It is proved that the Schrödinger equation together with the nonlinear equation of hydrodynamic type for E and H are invariant with respect to the Galilei algebra. New Poincare-invariant...
Research Article

New approach to the complete sum of products of the twisted (h, q)-Bernoulli numbers and polynomials

Yilmaz Simsek, Veli Kurt, Daeyeoul Kim
Pages: 44 - 56
In this paper, by using q-Volkenborn integral[10], the first author[25] constructed new generating functions of the new twisted (h, q)-Bernoulli polynomials and numbers. We define higher-order twisted (h, q)-Bernoulli polynomials and numbers. Using these numbers and polynomials, we obtain new approach...
Research Article

The graphical calculus for ribbon categories: Algebras, modules, Nakayama automorphisms

Jurgen Fuchs
Pages: 44 - 54
The graphical description of morphisms in rigid monoidal categories, in particular in ribbon categories, is summarized. It is illustrated with various examples of algebraic structures in such categories, like algebras, (weak) bi-algebras, Frobenius algebras, and modules and bimodules. Nakayama automorphisms...
Research Article

Nonclassical Symmetries for a Class of Reaction-Diffusion Equations: the Method of Heir-Equations

M.S. Hashemi, M.C. Nucci
Pages: 44 - 60
The nonclassical symmetries method is applied to a class of reaction-diffusion equations with nonlinear source, i.e. ut=uxx+cux+R(u, x). Several cases are obtained by using suitable solutions of the heir-equations as described in [M.C. Nucci, Nonclassical symmetries as special solutions of heir-equations,...
Short Communication

Geometrical symmetries of the Universal equation

V. Derjagin, A. Leznov
Pages: 46 - 50
It is shown that the group of geometrical symmetries of the Universal equation of D-dimensional space coincides with SL(D + 1, R).
Research Article

Bilinear recurrences and addition formulae for hyperelliptic sigma functions

Harry W. Braden, Victor Z. Enolskii, Andrew N.W. Hone
Pages: 46 - 62
The Somos 4 sequences are a family of sequences satisfying a fourth order bilinear recurrence relation. In recent work, one of us has proved that the general term in such sequences can be expressed in terms of the Weierstrass sigma function for an associated elliptic curve. Here we derive the analogous...
Research Article

On Conditionally Invariant Solutions of Magnetohydrodynamic Equations. Multiple Waves.

A.M. Grundland, P. Picard
Pages: 47 - 74
We present a version of the conditional symmetry method in order to obtain multiple wave solutions expressed in terms of Riemann invariants. We construct an abelian distribution of vector fields which are symmetries of the original system of PDEs subjected to certain first order differential constraints....
Research Article

Ehrenpreis Type Representations and Their Riemann­Hilbert Nonlinearisation

Athanassios S. Fokas
Pages: 47 - 61
We review a new method for studying boundary value problems for evolution PDEs. This method yields explicit results for a large class of evolution equations which iclude: (a) Linear equations with constant coefficients, (b) certain classes of linear equations with variable coefficients, and (c) integrable...
Research Article

New Symmetry Reductions for some Ordinary Differential Equations

M.L. Gandarias, E. Medina, C. Muriel
Pages: 47 - 58
In this work we derive potential symmetries for ordinary differential equations. By using these potential symmetries we find that the order of the ODE can be reduced even if this equation does not admit point symmetries. Moreover, in the case for which the ODE admits a group of point symmetries, we find...
Research Article

Generalized Virasoro algebra: left-symmetry and related algebraic and hydrodynamic properties

Mahouton Norbert Hounkonnou, Partha Guha, Tudor Ratiu
Pages: 47 - 73
Motivated by the work of Kupershmidt (J. Nonlin. Math. Phys. 6 (1998), 222 –245) we discuss the occurrence of left symmetry in a generalized Virasoro algebra. The multiplication rule is defined, which is necessary and sufficient for this algebra to be quasi-associative. Its link to geometry and nonlinear...
Research Article

Reduction by λ –symmetries and σ –symmetries: a Frobenius approach

Paola Morando
Pages: 47 - 59
Different kinds of reduction for ordinary differential equations, such as λ –symmetry and σ –symmetry reductions, are recovered as particular cases of Frobenius reduction theorem for distribution of vector fields. This general approach provides some hints to tackle the reconstruction problem and to solve...
Research Article

Nonlinear Water Waves on Uniform Current in Lagrangian Coordinates

Hung-Chu Hsu, Yang-Yih Chen, John R. C. Hsu, Wen-Jer Tseng
Pages: 47 - 61
This paper presents a new third-order trajectory solution in Lagrangian form for the water particles in a wave-current interaction flow based on an Euler–Lagrange transformation. The explicit parametric solution highlights the trajectory of a water particle and the wave kinematics above the mean water...
Research Article

Classical Lie symmetries and reductions for a generalized NLS equation in 2+1 dimensions

P. Albares, J. M. Conde, P. G. Estévez
Pages: 48 - 60
A non-isospectral linear problem for an integrable 2+1 generalization of the non linear Schrödinger equation, which includes dispersive terms of third and fourth order, is presented. The classical symmetries of the Lax pair and the related reductions are carefully studied. We obtain several reductions...
Research Article

On the Recurrence Coefficients for Generalized q-Laguerre Polynomials

Galina Filipuk, Christophe Smet
Pages: 48 - 56
In this paper we consider a semi-classical variation of the weight related to the q-Laguerre polynomials and study their recurrence coefficients. In particular, we obtain a second degree second order discrete equation which in particular cases can be reduced to either the qPV or the qPIII equation.
Research Article

On the (2+1)-Dimensional Extension of 1-Dimensional Toda Lattice Hierarchy

Yuji Ogawa
Pages: 48 - 65
We introduce a (2+1)-dimensional extension of the 1-dimensional Toda lattice hierar- chy. The hierarchy is given by two different formulations. For the first formulation, we obtain the bilinear identity for the ? -functions and construct explicit solutions ex- pressed by Wronski determinants. For the...
Research Article

Bilinear Approach to Supersymmetric KdV Equation

A.S. Carstea
Pages: 48 - 52
Extending the gauge-invariance principle for functions of the standard bilinear fomalism to the supersymmetric case, we define N = 1 supersymmetric Hirota operators. Using them, we bilinearize SUSY KdV equation. The solution for multiple collisions of super-solitons is given.
Research Article

Solutions and Lax Pairs based on Bilinear Bäcklund Transformations of Some Supersymmetric Equations

Lin Huang, Da-Jun Zhang
Pages: 48 - 61
The paper investigates solutions and Lax pairs through bilinear Bäcklund transformations for some supersymmetric equations. We derive variety of solutions from the known bilinear Bäcklund transformations. Besides, using the gauge invariance of (super) Hirota bilinear derivatives we may get deformed bilinear...
Research Article

On Invariants of Immersions of an n-Dimensional Manifold in an n-Dimensional Pseudo-Euclidean Space*

Djavvat Khadjiev
Pages: 49 - 70
Let Epn be the n-dimensional pseudo-Euclidean space of index p and M(n, p) the group of all transformations of Epn generated by pseudo-orthogonal transformations and parallel translations. We describe the system of generators of the differential field of all M(n, p)-invariant differential...
Research Article

On Integration of the Nonlinear d'Alembert-Eikonal System and Conditional Symmetry of Nonlinear Wave Equations

Renat Z. Zhdanov
Pages: 49 - 61
We study integrability of a system of nonlinear partial differential equations consisting of the nonlinear d'Alembert equation 2u = F(u) and nonlinear eikonal equation uxµ uxµ = G(u) in the complex Minkowski space R(1, 3). A method suggested makes it possible to establish necessary and sufficient compatibility...
Research Article

Basis of Joint Invariants for (1 + 1) Linear Hyperbolic Equations

I.K. Johnpillai, F.M. Mahomed, C. Wafo Soh
Pages: 49 - 59
We obtain a basis of joint or proper differential invariants for the scalar linear hperbolic partial differential equation in two independent variables by the infinitesimal method. The joint invariants of the hyperbolic equation consist of combinations of the coefficients of the equation and their derivatives...
Research Article

Deformation quantization for almost-Kähler manifolds

Martin Schlichenmaier
Pages: 49 - 54
On an arbitrary almost-Kähler manifold, starting from a natural affine connection with nontrivial torsion which respects the almost-Kähler structure, in joint work with A. Karabegov a Fedosov-type deformation quantization on this manifold was costructed. This contribution reports on the result and supplies...
Research Article

On the Recovery of the Free Surface from the Pressure within Periodic Traveling Water Waves

Joachim Escher, Torsten Schlurmann
Pages: 50 - 57
We present a consistent derivation of the pressure transfer function for small amplitude waves within the framework of linear wave theory and discuss some nonlinear aspects.
Short Communication

On Algebraic Integrability of the Deformed Elliptic Calogero­Moser Problem

L.A. Khodarinova, I.A. Prikhodski
Pages: 50 - 53
Algebraic integrability of the elliptic Calogero­Moser quantum problem related to the deformed root systems A2(2) is proved. Explicit formulae for integrals are found.
Research Article

Construction of Special Solutions for Nonintegrable Systems

Sergey Yu. Vernov
Pages: 50 - 63
The Painlev´e test is very useful to construct not only the Laurent series solutions of systems of nonlinear ordinary differential equations but also the elliptic and trigonmetric ones. The standard methods for constructing the elliptic solutions consist of two independent steps: transformation of a...
Research Article

Tunnelling in Nonlocal Evolution Equations

Giovanni Bellettini, Anna De Masi, Errico Presutti
Pages: 50 - 63
We study "tunnelling" in a one-dimensional, nonlocal evolution equation by assigning a penalty functional to orbits which deviate from solutions of the evolution equation. We discuss the variational problem of computing the minimal penalty for orbits which connect two stable, stationary solutions.
Research Article

Regularity of Steady Periodic Capillary Water Waves with Constant Vorticity

Calin Iulian Martin
Pages: 51 - 57
We prove a regularity result for steady periodic travelling capillary waves of small amplitude at the free surface of water in a flow with constant vorticity over a flat bed.
Research Article

Classical Lie Symmetries and Reductions of a Nonisospectral Lax Pair

P. G. Estévez, M. L. Gandarias, J. Lucas
Pages: 51 - 60
The classical Lie method is applied to a nonisospectral problem associated with a system of partial differential equations in 2 + 1 dimensions (Maccari A, J. Math. Phys. 12 (1998) 6547–6551.). Identification of the classical Lie symmetries provides a set of reductions that give rise to different nontrivial...
Research Article

Contact Symmetry of Time-Dependent Schrödinger Equation for a Two-Particle System: Symmetry Classification of Two-Body Central Potentials

P. Rudra
Pages: 51 - 65
Symmetry classification of two-body central potentials in a two-particle Schrödinger equation in terms of contact transformations of the equation has been investigated. Explicit calculation has shown that they are of the same four different classes as for the point transformations. Thus in this problem...
Research Article

Nonlinearized Perturbation Theories

Miloslav Znojil
Pages: 51 - 62
A brief review is presented of the two recent perturbation algorithms. Their common idea lies in a not quite usual treatment of linear Schrödinger equations via nonlinear mathematical means. The first approach (let us call it a quasi-exact perturbation theory, QEPT) tries to get the very zero-order approximants...
Research Article

Symmetry Reduction and Exact Solutions of the Yang-Mills Equations

Victor Lahno, Renat Zhdanov, Wilhelm Fushchych
Pages: 51 - 72
Research Article

The Poincaré–­Nekhoroshev Map

Giuseppe Gaeta
Pages: 51 - 64
We study a generalization of the familiar Poincaré map, first implicitely introduced by N N Nekhoroshev in his study of persistence of invariant tori in hamiltonian systems, and discuss some of its properties and applications. In particular, we apply it to study persistence and bifurcation of invariant...
Research Article

On (q, h)-Analogue of Fractional Calculus

Jan Čermák, Luděk Nechvátal
Pages: 51 - 68
The paper discusses fractional integrals and derivatives appearing in the so-called (q, h)-calculus which is reduced for h = 0 to quantum calculus and for q = h = 1 to difference calculus. We introduce delta as well as nabla version of these notions and present their basic properties. Furthermore, we...
Research Article

A Hidden Hierarchy for GD4

Paolo Casati
Pages: 53 - 57
A reduction process to construct hidden hierarchies corresponding to the Gelfand­ Dickey ones is outlined in a specific example, not yet treated in the literature.
Research Article

The Motion of a Gyrostat in a Central Gravitational Field: Phase Portraits of an Integrable Case

M.C. Balsas, E. S. Jiménez, J. A. Vera
Pages: 53 - 64
In this paper we describe the Hamiltonian dynamics, in some invariant manifolds of the mo- tion of a gyrostat in Newtonian interaction with a spherical rigid body. Considering a first integrable approximation of this roto-translatory problem, by means of Liouville-Arnold the- orem and some specifics...
Research Article

An L2 Norm Trajectory-Based Local Linearization for Low Order Systems

Fethi Belkhouche
Pages: 53 - 72
This paper presents a linear transformation for low order nonlinear autonomous diferential equations. The procedure consists of a trajectory-based local linearization, which approximates the nonlinear system in the neighborhood of its equilibria. The approximation is possible even in the non-hyperbolic...
Research Article

Orthogonalization of Graded Sets of Vectors

I.A. Shreshevskii
Pages: 54 - 58
I propose an orthogonalization procedure preserving the grading of the initial graded set of linearly independent vectors. In particular, this procedure is applicable for orthonormalization of any countable set of polynomials in several (finitely many) ideterminates.
Research Article

The Integrability of Lie-invariant Geometric Objects Generated by Ideals in the Grassmann Algebra

D.L. Blackmore, Y.A. Prykarpatsky, R.V. Samulyak
Pages: 54 - 67
We investigate closed ideals in the Grassmann algebra serving as bases of Lie-invariant geometric objects studied before by E.Cartan. Especially, the E.Cartan theory is enlarged for Lax integrable nonlinear dynamical systems to be treated in the frame work of the Wahlquist Estabrook prolongation structures...
Research Article

Solving the constrained modified KP hierarchy by gauge transformations

Huizhan Chen, Lumin Geng, Na Li, Jipeng Cheng
Pages: 54 - 68
In this paper, we mainly investigate two kinds of gauge transformations for the constrained modified KP hierarchy in Kupershmidt-Kiso version. The corresponding gauge transformations are required to keep not only the Lax equation but also the Lax operator. For this, by selecting the special generating...
Research Article

Finite genus solutions for Geng hierarchy

Zhu Li
Pages: 54 - 65
The Geng hierarchy is derived with the aid of Lenard recursion sequences. Based on the Lax matrix, a hyperelliptic curve 𝒦n + 1 of arithmetic genus n+1 is introduced, from which meromorphic function ϕ is defined. The finite genus solutions for Geng hierarchy are achieved according to asymptotic properties...
Research Article

New Geometrical Applications of the Elliptic Integrals: The Mylar Balloon

Ivaïlo M. Mladenov
Pages: 55 - 65
An explicit parameterization in terms of elliptic integrals (functions) for the Mylar balloon is found which then is used to calculate various geometric quantities as well as to study all kinds of geodesics on this surface.
Research Article

Description of a Class of 2-Groups

Tatjana Gramushnjak, Peeter Puusemp
Pages: 55 - 65
Let n be an integer such that n 3 and Cm denote a cyclic group of order m . It is proved that there exist exactly 17 non-isomorphic groups of order 22n+1 which can be represented as a semidirect product (C2n × C2n ) C2. These groups are given by generators and defining relations.
Research Article

Uq(𝒢^) Heisenberg Families

A. Zuevsky
Pages: 55 - 64
We explicitly describe Heisenberg families of elements in an arbitrary grading subspaces of the quantized universal enveloping algebra Uq(𝒢^) of an affine Kac–Moody algebra 𝒢^ in the Drinfeld formulation.
Research Article

Higher order Painlevé system of type D2n+2(1) and monodromy preserving deformation

Kenta Fuji, Keisuke Inoue, Keisuke Shinomiya, Takao Suzuki
Pages: 57 - 69
The higher order Painlevé system of type D2n+2(1) was proposed by Y. Sasano as an extension of PVI for the affine Weyl group symmetry with the aid of algebraic geometry for Okamoto initial value space. In this article, we give it as the monodromy preserving deformation of a Fuchsian system.
Research Article

On Exact Solution of a Classical 3D Integrable Model

S.M. Sergeev
Pages: 57 - 72
We investigate some classical evolution model in the discrete 2+1 space-time. A map, giving an one-step time evolution, may be derived as the compatibility condition for some systems of linear equations for a set of auxiliary linear variables. Dynamical variables for the evolution model are the coefficients...
Research Article

Solitons in Yakushevich-like models of DNA dynamics with improved intrapair potential

Giuseppe Gaeta
Pages: 57 - 81
The Yakushevich model provides a very simple pictures of DNA torsion dynamics, yet yields remarkably correct predictions on certain physical characteristics of the dynamics. In the standard Yakushevich model, the interaction between bases of a pair is modelled by a harmonic potential, which becomes anharmonic...
Research Article

On the Transformations of the Sixth Painlevé Equation

Valery I. Gromak, Galina Filipuk
Pages: 57 - 68
In this paper we investigate relations between different transformations of the slutions of the sixth Painlevé equation. We obtain nonlinear superposition formulas linking solutions by means of the Bäcklund transformation. Algebraic solutions are also studied with the help of the Bäcklund transformation.
Research Article

Solution formulas for the two-dimensional Toda lattice and particle-like solutions with unexpected asymptotic behaviour

Tomas Nilson, Cornelia Schiebold
Pages: 57 - 94
The first main aim of this article is to derive an explicit solution formula for the scalar two-dimensional Toda lattice depending on three independent operator parameters, ameliorating work in [31]. This is achieved by studying a noncommutative version of the 2d-Toda lattice, generalizing its soliton...
Research Article

On the Non-Dimensionalisation, Scaling and Resulting Interpretation of the Classical Governing Equations for Water Waves

Adrian Constantin, Robin Stanley Johnson
Pages: 58 - 73
In this note we describe the underlying principles — and pitfalls — of the process of non-dimensionalising and scaling the equations that model the classical problem in water waves. In particular, we introduce the two fundamental parameters (associated with amplitude and with wave length) and show how...
Research Article

Dispersion Relations for Steady Periodic Water Waves of Fixed Mean-Depth with an Isolated Bottom Vorticity Layer

David Henry
Pages: 58 - 71
In this paper we obtain the dispersion relations for small-amplitude steady periodic water waves, which propagate over a flat bed with a specified mean depth, and which exhibit discontinuous vorticity. We take as a model an isolated layer of constant nonzero vorticity adjacent to the flat bed, with irrotational...
Research Article

Algebraic Linearization of Hyperbolic Ruijsenaars­Schneider Systems

R. Caseiro, J.P. Françoise
Pages: 58 - 61
In this article, we present an explicit linearization of dynamical systems of RuijsenaarSchneider (RS) type and of the perturbations introduced by F Calogero [2] of these systems with all orbits periodic of the same period. The existence of this linearization and its algebraic nature relies on the dynamical...
Research Article

Soliton Asymptotics of Rear Part of Non-Localized Solutions of the Kadomtsev-Petviashvili Equation

Anne Boutet de Monvel, Eugene Khruslov
Pages: 58 - 76
We construct non-localized, real global solutions of the Kadomtsev-Petviashvili-I eqution which vanish for x - and study their large time asymptotic behavior. We prove that such solutions eject (for t ) a train of curved asymptotic solitons which move behind the basic wave packet.
Research Article

Superanalogs of the Calogero Operators and Jack Polynomials

A. Sergeev
Pages: 59 - 64
A depending on a complex parameter k superanalog SL of Calogero operator is costructed; it is related with the root system of the Lie superalgebra gl(n|m). For m = 0 we obtain the usual Calogero operator; for m = 1 we obtain, up to a change of indterminates and parameter k the operator constructed by...
Research Article

Some Special Integrable Surfaces

M. Gürses
Pages: 59 - 66
We consider surfaces arising from integrable partial differential equations and from their deformations. Symmetries of the equation, gauge transformation of the corrsponding Lax pair and spectral parameter transformations are the deformations which lead infinitely many integrable surfaces. We also study...
Research Article

On the Origins of Symmetries of Partial Differential Equations: the Example of the Korteweg-de Vries Equation

Keshlan S. Govinder, Barbara Abraham-Shrauner
Pages: 60 - 68
Type II hidden symmetries of partial differential equations () are extra symme- tries in addition to the inherited symmetries of the differential equations which arise when the number of independent and dependent variables is reduced by a Lie point symmetry. (Type I hidden symmetries arise in the increase...
Research Article

Antireduction and exact solutions of nonlinear heat equations

Wilhelm Fushchych, Renat Zhdanov
Pages: 60 - 64
We construct a number of ansatzes that reduce one-dimensional nonlinear heat equations to systems of ordinary differential equations. Integrating these, we obtain new exact solution of nonlinear heat equations with various nonlinearities.
Research Article

A Basis of Conservation Laws for Partial Differential Equations

A.H. Kara, F.M. Mahomed
Pages: 60 - 72
The classical generation theorem of conservation laws from known ones for a system of differential equations which uses the action of a canonical Lie­Bäcklund generator is extended to include any Lie­Bäcklund generator. Also, it is shown that the Lie algebra of Lie­Bäcklund symmetries of a conserved...
Research Article

On the Darboux integrability of the Painlevé II equations

Jaume Llibre, Claudia Valls
Pages: 60 - 75
In this paper we prove the non–existence of Darboux first integrals for the Painlevé II equations x.=y−z2−x2,y.=α+12+2xy,ż=1 for all values of α ∊ ℂ \ {αn: n = 2,4,…}. These αn are real and larger than −1/2.
Research Article

On Modulated NLS-Ermakov Systems

Colin Rogers, Kwok Chow
Pages: 61 - 74
Spatial modulated coupled nonlinear Schrödinger systems with symmetry reduction to integrable Ermakov and Ermakov-Painlevé subsystems are investigated.
Research Article

A Class of Semilinear Fifth-Order Evolution Equations: Recursion Operators and Multipotentialisations

Marianna Euler, Norbert Euler
Pages: 61 - 75
We apply a list of criteria which leads to a class of fifth-order symmetry-integrable evolution equations. The recursion operators for this class are given explicitly. Multipotentialisations are then applied to the equations in this class in order to extend this class of integrable equations.
Research Article

Lagrangians For Equations of Painlevé Type by Means of The Jacobi Last Multiplier

G. D’ambrosi, M. C. Nucci
Pages: 61 - 71
We apply the method of Jacobi Last Multiplier to the fifty second-order ordinary differential equations of Painlevé type as given in Ince in order to obtain a Lagrangian and consequently solve the inverse problem of Calculus of Variations for those equations. The easiness and straightforwardness of Jacobi’s...
Research Article

Quasi-Periodic Solutions of Coupled KDV Type Equations

Bo Xue, Fang Li, Xianguo Geng
Pages: 61 - 77
A hierarchy of new nonlinear evolution equations is proposed, which are composed of the positive and negative coupled KdV flows. Based on the theory of algebraic curve, the corresponding flows are straightened under the Abel-Jacobi coordinates. The meromorphic function ϕ, the Baker-Akhiezer vector ψ¯ ,...
Research Article

On Huygens' Principle for Dirac Operators and Nonlinear Evolution Equations

Fabio A.C.C. Chalub, Jorge P. Zubelli
Pages: 62 - 68
We exhibit a class of Dirac operators that possess Huygens' property, i.e., the support of their fundamental solutions is precisely the light cone. This class is obtained by considering the rational solutions of the modified Korteweg-de Vries hierarchy.
Research Article

The Derivative Nonlinear Schrödinger Equation in Analytic Classes

Zoran Grujić, Henrik Kalisch
Pages: 62 - 71
The derivative nonlinear Schrödinger equation is shown to be locally well-posed in a class of functions analytic on a strip around the real axis. The main feature of the result is that the width of the strip does not shrink in time. To overcome the derivative loss, Kato-type smoothing results and space-time...
Research Article

New Solvable Many-Body Model of Goldfish Type

F. Calogero
Pages: 62 - 80
A new solvable N-body model of goldfish type is identified. Its Newtonian equations of motion read as follows: z¨n=-6z˙nzn-4zn3+32(z˙n+2zn2)∑k=1N(z˙ kzk+2zk)+2∑𝓁=1,𝓁≠nN[(z˙n+2zn2)(z˙𝓁+2z𝓁2)zn-z𝓁],      n=1,…,N, where...
Research Article

Conditional and Nonlocal Symmetry of Nonlinear Heat Equation

Mykola I. Serov
Pages: 63 - 67
Conditional symmetry We investigate conditional symmetry in three directions. The first direction is a research of the Q-conditional symmetry. The second direction is studying conditional symmetry when an algebra of invariance is known and an additional condition is unknown. The third direction is the...
Research Article

Orthogonal matrix polynomials satisfying first order differential equations: a collection of instructive examples

Mirta M. Castro, F. Alberto GRUNBAUM
Pages: 63 - 76
We describe a few families of orthogonal matrix polynomials of size N × N satisfying first order differential equations. This problem differs from the recent efforts reported for instance in [7] (Orthogonal matrix polynomials satisfying second order differential equations, Internat. Math. Research Notices,...
Research Article

The Adjoint Representation of Quantum Algebra Uq(sl(2))

Č. Burdík, O. Navrátil, S. Pošta
Pages: 63 - 75
Starting from any representation of the Lie algebra ℊ on the finite dimensional vector space V we can construct the representation on the space Aut(V ). These representations are of the type of ad. That is one of the reasons, why it is important to study the adjoint representation of the Lie algebra...
Research Article

Vortex Line Representation for the Hydrodynamic Type Equations

E.A. Kuznetsov
Pages: 64 - 80
In this paper we give a brief review of the recent results obtained by the author and his co-authors for description of three-dimensional vortical incompressible flows in the hydrodynamic type systems. For such flows we introduce a new mixed LagrangiaEulerian description - the so called vortex line representation...
Research Article

On Dispersionless BKP Hierarchy and its Reductions

L.V. Bogdanov, B.G. Konopelchenko
Pages: 64 - 73
Integrable dispersionless Kadomtsev-Petviashvili (KP) hierarchy of B type is consiered. Addition formula for the -function and conformally invariant equations for the dispersionless BKP (dBKP) hierarchy are derived. Symmetry constraints for the dBKP hierarchy are studied.
Research Article

Existence of Dark Soliton Solutions of the Cubic Nonlinear Schrödinger Equation with Periodic Inhomogeneous Nonlinearity

Juan Belmonte-Beitia, Pedro J Torres
Pages: 65 - 72
In this paper, we give a proof of the existence of stationary dark soliton solutions of the cubic nonlinear Schrödinger equation with periodic inhomogeneous nonlinearity, together with an analytical example of a dark soliton.
Research Article

Hard Loss of Stability in Painlevé-2 Equation

O.M. Kiselev
Pages: 65 - 95
A special asymptotic solution of the Painlevé-2 equation with small parameter is stdied. This solution has a critical point t corresponding to a bifurcation phenomenon. When t < t the constructed solution varies slowly and when t > t the solution oscillates very fast. We investigate the transitional...
Research Article

A completely integrable system associated with the Harry-Dym hierarchy

Zhijun Qiao
Pages: 65 - 74
By use of nonlinearization method about spectral problem, a classical completely integrable system associated with the Harry-Dym (HD) hierarchy is obtained. Furthermore, the involutive solution of each equation in the HD hierarchy is presented, in particular, the involutive solution of the well-known...
Research Article

Nonlinear Schrödinger, Infinite Dimensional Tori and Neighboring Tori

M. Schwarz Jr.
Pages: 65 - 77
In this work, we explain in what sense the generic level set of the constants of motion for the periodic nonlinear Schrödinger equation is an infinite dimensional torus on which each generalized nonlinear Schrödinger flow is reduced to straight line almost periodic motion, and describe how neighboring...
Research Article

Massless Thirring Model in Canonical Quantization Scheme

S. E. Korenblit, V. V. Semenov
Pages: 65 - 74
It is shown that the exact solubility of the massless Thirring model in the canonical quantization scheme originates from the intrinsic hidden linearizability of its Heisenberg equations in the method of dynamical mappings. The corresponding role of inequivalent representations of free massless Dirac...
Research Article

Symmetries of a Class of Nonlinear Fourth Order Partial Differential Equations

Peter A. Clarkson, Thomas J. Priestley
Pages: 66 - 98
In this paper we study symmetry reductions of a class of nonlinear fourth order partial differential equations utt = u + u2 xx + uuxxxx + µuxxtt + uxuxxx + u2 xx, (1) where , , , and µ are arbitrary constants. This equation may be thought of as a fourth order analogue of a generalization of the Camassa-Holm...
Research Article

Leading order integrability conditions for differential-difference equations

Mark S. Hickman
Pages: 66 - 86
A necessary condition for the existence of conserved densities and fluxes of a differential-difference equation which depend on q shifts, for q sufficiently large, is presented. This condition depends on the eigenvalues of the leading terms in the differential-difference equation. It also gives, explicitly,...
Research Article

Rewriting in Operads and PROPs

Lars Hellström
Pages: 66 - 75
This paper is an informal collection of observations on how established rewriting techniques can be applied to or need to be adapted for use in non-associative algebras, operads, and PROPs.
Research Article

von Neumann Quantization of Aharonov-Bohm Operator with Interaction: Scattering Theory, Spectral and Resonance Properties

Gilbert Honnouvo, Mahouton Norbert Hounkonnou, Gabriel Yves Hugues
Pages: 66 - 71
Using the theory of self-adjoint extensions, we study the interaction model formally given by the Hamiltonian H + V (r), where H is the Aharonov-Bohm Hamiltonian and V (r) is the -type interaction potential on the cylinder of radius R . We give the mathematical definition of the model, the self-adjointness...
Research Article

The gauge transformation of the modified KP hierarchy

Jipeng Cheng
Pages: 66 - 85
In this paper, we firstly investigate the successive applications of three elementary gauge transformation operators Ti with i = 1,2,3 for the mKP hierarchy in Kupershmidt-Kiso version, and find that the gauge transformation operators Ti can not commute with each other. Then two types of gauge transformation...
Research Article

Is My ODE a Painlevé Equation in Disguise?

Jarmo Hietarinta, Valery Dryuma
Pages: 67 - 74
Painlevé equations belong to the class y +a1 y 3 +3a2 y 2 +3a3 y +a4 = 0, where ai = ai(x, y). This class of equations is invariant under the general point transformation x = (X, Y ), y = (X, Y ) and it is therefore very difficult to find out whether two equations in this class are related. We describe...