Journal of Nonlinear Mathematical Physics

Volume 16, Issue 1, March 2013
Letter to Editor

1. Some Examples of Algebraic Geodesics on Quadrics

A. M. Perelomov
Pages: 1 - 5
In this note we give the conditions for the existence of algebraic geodesics on some two-dimensional quadrics, namely, on hyperbolic paraboloids and elliptic paraboloids. It appears that in some cases, such geodesics are the rational space curves.
Research Article

2. Bright N-Solitons For The Intermediate Nonlinear Schrödinger Equation

Yohei Tutiya
Pages: 7 - 23
A previously unknown bright N-soliton solution for an intermediate nonlinear Schrödinger equation of focusing type is presented. This equation is constructed as a reduction of an integrable system related to a Sato equation of a 2-component KP hierarchy for certain differential-difference dispersion...
Research Article

3. The Bogomolny Decomposition for Systems of Two Generalized Nonlinear Partial Differential Equations of the Second Order

Ł. Stȩpień, D. Sokalska, K. Sokalski
Pages: 25 - 34
Using a concept of strong necessary conditions we derive the Bogomolny decomposition for systems of two generalized elliptic and parabolic nonlinear partial differential equations (NPDE) of the second order. The generalization means that the equation coefficients depend on the field variables. According...
Research Article

4. Geometrization of the Leading Term in Acoustic Gaussian Beams

Matias F. Dahl
Pages: 35 - 45
We study Gaussian beams for the wave equation on a Riemannian manifold. For the transport equation we geometrize the leading term at the center of the Gaussian beam. More precisely, if u(x,t)=eiPθ(x,t)(u0(x,t)+u1(x,t)iP+u2(x,t)(iP)2+⋯) is a Gaussian beam propagating along a geodesic c, then we show...
Research Article

5. 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

6. 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

7. Group Analysis and Heir-Equations for Thin Liquid Films

S. Martini, N. Ciccoli, M. C. Nucci
Pages: 77 - 92
Lie group analysis is applied to a mathematical model for thin liquid films, namely a nonlinear fourth order partial differential equation in two independent variables. A three-dimensional Lie symmetry algebra is found and reductions to fourth order ordinary differential equations are obtained by using...
Research Article

8. A Mean-Field Version of the SSB Model For X-Chromosome Inactivation

Giuseppe Gaeta
Pages: 93 - 103
Nicodemi and Prisco recently proposed a model for X-chromosome inactivation in mammals, explaining this phenomenon in terms of a spontaneous symmetry-breaking mechanism [Phys. Rev. Lett. 99 (2007) 108104]. Here we provide a mean-field version of their model.
Research Article

9. Isochronous Dynamical System and Diophantine Relations I

F. Calogero, S. Iona
Pages: 105 - 116
We identify a solvable dynamical system — interpretable to some extent as a many-body problem — and point out that — for an appropriate assignment of its parameters — it is entirely isochronous, namely all its nonsingular solutions are completely periodic (i.e., periodic in all degrees of freedom) with...