Klein Gordon Zakharov Equations Research Articles

High order energy-preserving method for the space fractional Klein–Gordon-Zakharov equations

The space fractional Klein–Gordon-Zakharov equations are transformed into the multi-symplectic structure system by introducing new auxiliary variables. The multi-symplectic system, which satisfies the multi-symplectic conservation, local energy and momentum conservation, is discretizated into the semi-discrete multi-symplectic system by the Fourier pseudo-spectral method. The second order multi-symplectic average vector field method is applied to the semi-discrete system. The fully discrete energy preserving scheme of the space fractional Klein–Gordon-Zakharov equation is obtained. Based on the composition method, a fourth order energy preserving scheme of the Riesz space fractional Klein–Gordon-Zakharov equations is also obtained. Numerical experiments confirm that these new schemes can have computing ability for a long time and can well preserve the discrete energy conservation property of the equations.

Classical symmetries of the Klein–Gordon–Zakharov equations with time-dependent variable coefficients

In this article, we employ the group-theoretic methods to explore the Lie symmetries of the Klein–Gordon–Zakharov equations, which include time-dependent coefficients. We obtain the Lie point symmetries admitted by the Klein–Gordon–Zakharov equations along with the forms of variable coefficients. From the resulting symmetries, we construct similarity reductions.The similarity reductions are further analyzed using the power series method/approach and furnished the series solutions. Additionally, the convergence of the series solutions has been reported.

Superconvergence analysis of an [formula omitted]-Galerkin mixed FEM for Klein–Gordon–Zakharov equations with power law nonlinearity

This paper aims to study an H1-Galerkin mixed finite element method (FEM) for Klein–Gordon–Zakharov (KGZ) equations with power law nonlinearity. The bilinear element and zero-order Raviart–Thomas element (Q11/Q10×Q01) are taken as approximation spaces for the original variables p, ϕ and the auxiliary variables u=∇p and ψ=∇ϕ, respectively. The supercloseness and superconvergence estimates of order O(h2+τ2) are presented for p and ϕ in the H1 norm and u and ψ in the L2 norm, which improve the known results that the original variable ϕ can only reach optimal error estimate shown in numerical experiments without theoretical analysis. Here h is the subdivision parameter and τ is the time step. Finally, some numerical results are provided to support the theoretical analysis.

NOVEL APPROACHES TO FRACTIONAL KLEIN–GORDON–ZAKHAROV EQUATION

The Klein–Gordon–Zakharov equation is an important and interesting model in physics. A fractional Klein–Gordon–Zakharov model is described by employing beta-derivative. Some new solitary wave solutions are acquired by utilizing the fractional rational [Formula: see text]–[Formula: see text] method and fractional [Formula: see text] method. Some 3D graphs are depicted to elaborate these new solitary wave solutions. The work is very helpful to study other related types of fractional evolution equations.

New soliton solutions of Simplified Modified Camassa Holm equation, Klein–Gordon–Zakharov equation using First Integral Method and Exponential Function Method

In this article, new soliton solutions of Simplified Modified Camassa–Holm (SMCH) equation and Klein–Gordon–Zakharov (KGZ) equation are acquired. First Integral Method (FIM) and Exponential Function Method (EFM) are employed to construct the soliton solutions of SMCH equation and KGZ equation. The solution by these approaches can be obtained by utilizing symbolic computational softwares like Maple and Mathematica. The results suggest that the EFM and FIM are effective and useful techniques to handle non-linear problems.

New exact solutions to the coupled (n + 1)-dimensional Klein–Gordon–Zakharov equation with power law nonlinearities

In this paper, a special class of exact solutions of the coupled higher-dimensional Klein–Gordon–Zakharov (KGZ) equation with power law nonlinearities is constructed explicitly by separation transformation method. One merit of this work is that when the dimension is larger than one, there is an arbitrary function [Formula: see text], which is used to search for more general exact solutions of the coupled higher-dimensional KGZ equation. As a result, the Jacobi elliptic function solutions and soliton solutions with free parameters are derived, which lead to rich localized nonlinear structures of the coupled higher-dimensional KGZ equation with power law nonlinearities.

Numerical simulation of two‐dimensional and three‐dimensional generalizedKlein–Gordon–Zakharovequations with power law nonlinearity via a meshless collocation method based on barycentric rational interpolation

AbstractThis study presents numerical simulations of generalized two‐dimensional (2D) and three‐dimensional (3D) Klein–Gordon–Zakharov (KGZ) equations with power law nonlinearity, which are coupled nonlinear partial differential equations. A meshless collocation method based on barycentric rational interpolation is developed for space variable of the KGZ equations. For time discretization, an explicit low storage fourth order Runge Kutta method is proposed after transforming KGZ equations to system of ordinary differential equations by introducing auxiliary variables.L∞andL2error norms for some test problems are computed. Obtained numerical results and comparisons with finite element methods indicate that barycentric rational interpolation method is an efficient method for solving multidimensional generalized KGZ system numerically.

High accuracy analysis of Galerkin finite element method for Klein–Gordon–Zakharov equations

The main aim of this paper is to propose a Galerkin finite element method (FEM) for solving the Klein–Gordon–Zakharov (KGZ) equations with power law nonlinearity, and to give the error estimations of approximate solutions about the electronic fast time scale component q and the ion density deviation r. In which, the bilinear element is used for spatial discretization, and a second order difference scheme is implemented for temporal discretization. Moreover, by use of the combination of the interpolation and Ritz projection technique, and the interpolated postprocessing approach, for weaker regularity requirements of the exact solution, the superclose and global superconvergence estimations of q in H1−norm are deduced. At the same time, the superconvergence of the auxiliary variable φ (−Δφ=rt) in H1−norm and optimal error estimation of r in L2−norm are derived. Meanwhile, we also discuss the extensions of our scheme to more general finite elements. Finally, the numerical experiments are provided to confirm the validity of the theoretical analysis.

Some new families of exact solitary wave solutions of the Klein–Gordon–Zakharov equations in plasma physics

Some new families of exact solitary wave solutions of the Klein–Gordon–Zakharov equations in plasma physics

The solitary wave solutions to the Klein–Gordon–Zakharov equations by extended rational methods

In this paper, using the extended rational sine–cosine and rational sinh–cosh methods, we find new soliton solutions for the Klein–Gordon–Zakharov equations. The extended rational sine–cosine and rational sinh–cosh methods are prospering in finding soliton solutions of the Klein–Gordon–Zakharov equations. By means of these methods, we found some young solitons of the above mentioned equation. The conclusions we receive are dark, bright, and periodic. In addition, in order to imagine the underlying dynamics of the obtained soliton solutions, 2D and 3D plots are drawn.

Fast evaluation for the two-dimensional nonlinear coupled time–space fractional Klein–Gordon–Zakharov equations

In this paper, we develop a fast algorithm to solve the two-dimensional nonlinear coupled time–space fractional Klein–Gordon–Zakharov (KGZ) equations. The L2−1σ method based on an efficient sum-of-exponentials (SOE) approximation and a Fourier spectral method are used to approximate the time and space direction, respectively. And we use the previous time levels to deal with the nonlinear terms to obtain a linearized numerical scheme. Finally, a numerical example is given to show that our numerical method is of second order accuracy in time, spectral accuracy in space and the fast algorithm is effective.

Analysis of fractional Klein–Gordon–Zakharov equations using efficient method

Analysis of fractional Klein–Gordon–Zakharov equations using efficient method

Complex traveling-wave and solitons solutions to the Klein-Gordon-Zakharov equations

This paper studies complex solutions and solitons solutions to the Klein-Gordon-Zakharov equations (KGZEs). Solitons solutions including bright, dark, W-shape bright, breather also trigonometric function solutions and singular solutions of KGZEs are obtained by three integration algorithm. From the spatio-temporal and 3-D and 2-D contour plot, it is observed that obtained solutions move without any deformation that implies the steady state of solutions. Furthermore, these solutions will be helpful to explain the interactions in hight frequency plasma and solitary wave theory.

New solitary waves for the Klein–Gordon–Zakharov equations

This paper studies new solitary waves for the Klein–Gordon–Zakharov equations. The obtained results are diverse and some specific ones emerge as dark, bright and bell-shape. The two integration schemes lead to obtaining waves which propagate without deformation as illustrated in graphical representations. Our obtained results are more specific compared to those obtained by Refs. 8 and 31 [C. H. Zhao and Z. M. Sheng, Acta Phys. Sin. 53 (2004) 29; S. Yakada, B. Depelair, G. Betchewe and S. Y. Doka, Optik 197 (2019) 163108].

Existence of solutions of an explicit energy-conserving scheme for a fractional Klein–Gordon–Zakharov system

In the article Martínez et al. (2019) [7], the authors assumed the triviality of the existence of solutions of a finite-difference model for a fractional Klein–Gordon–Zakharov equation. It turns out that property is not trivial at all. In this short communication, we provide a proof of that result and, in the way, we mention some wrong proofs of similar results available in the literature. We believe that the report on the demonstration of this result will be a useful tool for researchers working on the numerical analysis of partial differential equations.

Corrigendum to “A numerically efficient and conservative model for a Riesz space-fractional Klein–Gordon–Zakharov system”

In the article [Commun Nonlinear Sci Numer Simul 2019;71:22–37], the authors provided an erroneous proof for the existence of solutions of a finite-difference model for a fractional Klein–Gordon–Zakharov equation. This letter is intended to provide a correct proof of that theorem.

Numerical simulation for solitary wave of Klein–Gordon–Zakharov equation based on the lattice Boltzmann model

This work reports a study of Klein–Gordon–Zakharov equation by using the lattice Boltzmann method. The Klein–Gordon–Zakharov equation describes the interaction of the Langmuir wave and the ion acoustic wave in plasma. Numerical simulations of the constructed lattice Boltzmann model for the Klein–Gordon–Zakharov equation show the propagation and the interaction of the (1+1) and (2+1) dimensional solitary waves. These simulation results are examined and compared by using different parameters and different schemes. This work indicates that the lattice Boltzmann method can be a very effective tool for the simulation of Klein–Gordon–Zakharov equation.

Group classification, conservation laws and Painlevé analysis for Klein–Gordon–Zakharov equations in (3 $$+$$ + 1)-dimension

In this paper, we study Klein–Gordon–Zakharov equations which describe the propagation of strong turbulence of the Langmuir wave in a high-frequency plasma. Using the symbolic manipulation tool Maple, the classifications of symmetry algebra are carried out, and the construction of several local non-trivial conservation laws based on a direct method of Anco and Bluman is illustrated. Starting with determination of symmetry algebra, the one- and two-dimensional optimal systems are constructed, and optimality is also established using various invariant functions of full adjoint action. Apart from classification and construction of several conservation laws, the Painleve analysis is also performed in a symbolic manner which describes the non-integrability of equations.

On the new wave behavior to the Klein–Gordon–Zakharov equations in plasma physics

In this study, the extended sinh-Gordon equation expansion method is used in constructing various exact solitary wave solutions to the Klein–Gordon–Zakharov equations. The Klein–Gordon–Zakharov equations is a nonlinear model describing the interaction between the Langmuir wave and the ion acoustic wave in a high-frequency plasma. We successfully construct some topological, non-topological, compound topological and non-topological, singular, compound singular solitons and singular periodic wave solutions. Under the choice of suitable values of the parameters, the 2D, 3D and contour graphs to some of the reported solutions are also plotted.

Application of conservation theorem and modified extended tanh-function method to (1+1)-dimensional nonlinear coupled Klein–Gordon–Zakharov equation

We found trivial conservation laws by conservation theorem and exact solutions modified extended tanh-function method of (1+1)-dimensional nonlinear coupled Klein–Gordon–Zakharov equation. The travelling wave solutions are expressed by the hyperbolic, trigonometric and rational functions. It is shown that the suggested method provides a powerful mathematical instrument for solving nonlinear equations in the science of mathematics, physics and engineering.