Fractional sine-Gordon Research Articles

A Fast H2N2 Finite Difference Scheme for the Fractional Sine-Gordon Equation

A Fast H2N2 Finite Difference Scheme for the Fractional Sine-Gordon Equation

Spectral algorithm for two-dimensional fractional sine-Gordon and Klein–Gordon models

Solitons and waves with memory effects are two examples of nonlinear wave phenomena that can be studied mathematically using the fractional nonlinear sine-Gordon equation. It is a modification of the traditional sine-Gordon equation that takes memory effects and nonlocal interactions into account by adding fractional derivatives. A more complex explanation of particle dynamics and interactions within relativistic quantum mechanics is made possible by the fractional Klein–Gordon model, a theoretical framework that expands the standard equation to include fractional derivatives. The study uses shifted Legendre–Gauss–Lobatto and shifted Legendre–Gauss–Radau collocation techniques to solve numerically two-dimensional sine-Gordon and Klein–Gordon models. The study handles two-dimensional sine-Gordon and Klein–Gordon models by extending a collocation approach using basis functions. It suggests a collocation technique that uses a suggested basis to automatically satisfy the conditions. The suggested methods’ spectral accuracy and efficiency are validated by numerical results.

Improved uniform error bounds of Lawson-type exponential integrator method for long-time dynamics of the high-dimensional space fractional sine-Gordon equation

Improved uniform error bounds of Lawson-type exponential integrator method for long-time dynamics of the high-dimensional space fractional sine-Gordon equation

A new method of solving the best approximate solution for a nonlinear fractional equation

A new method of solving the best approximate solution for nonlinear fractional equations with smooth and nonsmooth solutions in reproducing kernel space is proposed in the paper. The nonlinear equation outlines some important equations, such as fractional diffusion-wave equation, nonlinear Klein–Gordon equation and time-fractional sine-Gordon equation. By constructing orthonormal bases in reproducing kernel space using Legendre orthonormal polynomials and Jacobi fractional orthonormal polynomials, the best approximate solution is obtained by searching the minimum of residue in the sense of . Numerical experiments verify that the method has higher accuracy.

Optimal error estimation of two fast structure-preserving algorithms for the Riesz fractional sine-Gordon equation

The primary purpose of this paper is to develop and analyze two fast and conservative algorithms for the fractional sine-Gordon equation. The numerical schemes are derived by using the second-and fourth-order difference method in space and the implicit midpoint rule in time to approximate an equivalent system obtained via the energy quadratic method. In addition, the conservation, existence and uniqueness, and convergence of the two schemes are investigated. Based on the properties of the Toeplitz matrix, a fast algorithm is given in the calculation for the proposed schemes. Numerical experiments verify the theoretical analysis of the schemes, showing their efficiency and excellent behavior.

Data-driven soliton mappings for integrable fractional nonlinear wave equations via deep learning with Fourier neural operator

In this paper, we firstly extend the Fourier neural operator (FNO) to discovery the mapping between two infinite-dimensional function spaces, where one is the fractional-order index space {ϵ|ϵ∈(0,1)} in the fractional integrable nonlinear wave equations while another denotes the soliton solution in the spatio-temporal function space. In other words, once the FNO network is trained, for any given ϵ∈(0,1), the corresponding soliton solution can be quickly obtained. To be specific, the soliton solutions are learned for the fractional nonlinear Schrödinger (fNLS), fractional Korteweg–de Vries (fKdV), fractional modified Korteweg–de Vries (fmKdV) and fractional sine-Gordon (fsineG) equations. The FNO architecture is utilized to learn the soliton mappings of the above four equations. The data-driven solitons are also compared with exact solutions to illustrate the powerful approximation capability of the FNO. Moreover, we study the influences of several critical factors (e.g., activation functions containing Relu(x), Sigmoid(x), Swish(x) and the new one xtanh(x), channels of fully connected layer) on the performance of the FNO algorithm. As a result, we find that the xtanh(x) and Swish(x) functions perform better than the Relu(x) and Sigmoid(x) functions in the FNO, and the FNO network with a more-channel fully-connected layer performs better as we expect. These results obtained in this paper will be useful to further understand the neural networks for fractional integrable nonlinear wave equations and the mappings between two infinite-dimensional function spaces.

Local Fractional Homotopy Perturbation Method for Solving Coupled Sine-Gordon Equations in Fractal Domain

In this paper, the coupled local fractional sine-Gordon equations are studied in the range of local fractional derivative theory. The study of exact solutions of nonlinear coupled systems is of great significance for understanding complex physical phenomena in reality. The main method used in this paper is the local fractional homotopy perturbation method, which is used to analyze the exact traveling wave solutions of generalized nonlinear systems defined on the Cantor set in the fractal domain. The fractal wave with fractal dimension ε=ln2/ln3 is numerically simulated. Through numerical simulation, we find that the obtained solutions are of great significance to explain some practical physical problems.

A GENERALIZED METHOD AND ITS APPLICATIONS TO n-DIMENSIONAL FRACTIONAL PARTIAL DIFFERENTIAL EQUATIONS IN FRACTAL DOMAIN

A generalized local fractional Riccati differential equation (LFRDE) method, which is a combination of the local fractional Riccati differential equation method and the transformed rational function approach, is presented to obtain the non-differentiable exact traveling wave solutions for n-dimensional fractional partial differential equations. In order to verify the effectiveness of the method, the seventh-order local fractional Sawada–Kotera–Ito equation, the local fractional sine-Gordon equation and the local fractional Kadomtsev–Petviashvili equation in fractal domain are first considered. The obtained results show that the presented method involving fractal special functions, are powerful and effective for obtaining exact solutions of nonlinear fractional partial differential equations in fractal domains.

An expansion based on Sine-Gordon equation to Solve KdV and modified KdV equations in conformable fractional forms

An expansion method based on time fractional Sine-Gordon equation is implemented to construct some real and complex valued exact solutions to the Korteweg-de Vries and modified Korteweg-de Vries equations in time fractional forms. Compatible fractional traveling wave transform plays a key role to be able to apply homogeneous balance technique to set the predicted solution. The relation between trigonometric and hyperbolic functions based on fractional Sine-Gordon equation allows to form the exact solutions with multiplication of powers of hyperbolic functions. Some exact solutions in traveling wave forms are explicitly expressed by the proposed method for both the Korteweg-de Vries and modified Korteweg-de Vries equations.

Application of combination schemes based on radial basis functions and finite difference to solve stochastic coupled nonlinear time fractional sine-Gordon equations

Application of combination schemes based on radial basis functions and finite difference to solve stochastic coupled nonlinear time fractional sine-Gordon equations

Reproducing kernel Hilbert pointwise numerical solvability of fractional Sine-Gordon model in time-dependent variable with Dirichlet condition

In this analysis, the fractional sine-Gordon model in the time-dependent variable domain using Caputo non-integer order basis derivative is presented. The main purpose is to utilize the adaptation of the RKHA to construct PNS to various forms of TFSGM subject to the specific DBC. Several theoretical results are employed to interpret PNSs to such fractional models in the sense of the Hilbert space. The convergence of the RKHA and error estimates are derived to guarantee the PNS outcomes. This handling PNS depending on the bases generated from the Gram Schmidt process and can be immediately carried out to generate the Fourier expansion during a fast convergence order. The soundness and powerfulness of the utilized RKHA are explained by testing the numerical solvability of two TFSGMs. Several geometric plots and tabulated outcomes mentioned that the utilized numerical approach is delicate and accurate in the field of CTFPD. In the end, conclusion and future remarks are given.

A Numerical Scheme Based on the Chebyshev Functions to Find Approximate Solutions of the Coupled Nonlinear Sine-Gordon Equations with Fractional Variable Orders

In this article, a numerical method based on the shifted Chebyshev functions for the numerical approximation of the coupled nonlinear variable-order fractional sine-Gordon equations is shown. The variable-order fractional derivative is considered in the sense of Caputo-Prabhakar. To solve the problem, first, we obtain the operational matrix of the Caputo-Prabhakar fractional derivative of shifted Chebyshev polynomials. Then, this matrix and collocation method are used to reduce the solution of the nonlinear coupled variable-order fractional sine-Gordon equations to a system of algebraic equations which is technically simpler for handling. Convergence and error analysis are examined. Finally, some examples are given to test the proposed numerical method to illustrate the accuracy and efficiency of the proposed method.

A new approach to study nonlinear space-time fractional sine-Gordon and Burgers equations

In this study, we investigate a couple of nonlinear fractional differential equations namely, the sine-Gordon and Burgers equations in the sense of Riemann-Liouville fractional derivative. In order to examine exact solutions effectively applicable in relaxation and diffusion problems, crystal defects, solid-state physics, plasma physics, vibration theory, astrophysical fusion plasmas, scalar electrodynamics, etc. we introduce the new generalized -expansion method. The method is highly effective and a functional mathematical scheme to examine solitary wave solutions to diverse fractional physical models.

A linearly implicit structure-preserving scheme for the fractional sine-Gordon equation based on the IEQ approach

This paper aims to develop a linearly implicit structure-preserving numerical scheme for the space fractional sine-Gordon equation, which is based on the newly developed invariant energy quadratization method. First, we reformulate the equation as a canonical Hamiltonian system by virtue of the variational derivative of the functional with fractional Laplacian. Then, we utilize the fractional centered difference formula to discrete the equivalent system derived by the invariant energy quadratization method in space direction, and obtain a conservative semi-discrete scheme. Subsequently, the linearly implicit structure-preserving method is applied for the resulting semi-discrete system to arrive at a fully-discrete conservative scheme. The stability, solvability and convergence in the maximum norm of the numerical scheme are given. Furthermore, a fast algorithm based on the fast Fourier transformation technique is used to reduce the computational complexity in practical computation. Finally, numerical examples are provided to confirm our theoretical analysis results.

A periodic solution of the fractional sine-Gordon equation arising in architectural engineering

Many nonlinear vibrations arising in the engineering of architecture include noise and uncertain properties, and this paper suggests a fractional model to elucidate the properties. The fractional sine-Gordon equation with the Riemann–Liouville fractional derivative is used as an example to solve its periodic solution by the homotopy perturbation method. The frequency–amplitude relationship is obtained, and the effect of the fractional derivative order on the vibration property is discussed. Additionally, the harmonic resonance is also discussed. This preliminary research can be further extended to real applications.

A cardinal method to solve coupled nonlinear variable-order time fractional sine-Gordon equations

In this study, a computational approach based on the shifted second-kind Chebyshev cardinal functions (CCFs) is proposed for obtaining an approximate solution of coupled variable-order time-fractional sine-Gordon equations where the variable-order fractional operators are defined in the Caputo sense. The main ideas of this approach are to expand the unknown functions in tems of the shifted second-kind CCFs and apply the collocation method such that it reduces the problem into a system of algebraic equations. To algorithmize the method, the operational matrix of variable-order fractional derivative for the shifted second-kind CCFs is derived. Meanwhile, an effective technique for simplification of nonlinear terms is offered which exploits the cardinal property of the shifted second-kind CCFs. Several numerical examples are examined to verify the practical efficiency of the proposed method. The method is privileged with the exponential rate of convergence and provides continuous solutions with respect to time and space. Moreover, it can be adapted for other types of variable-order fractional problems straightforwardly.

Analysis of local discontinuous Galerkin method for time-space fractional sine-Gordon equations

The aim of the present paper is to introduce a numerical method for time-space fractional sine-Gordon equation. The fractional derivative on the space and on the time are considered in the sense of Reimann–Liouville (of order 1≤β≤2) and in the sense of Caputo (of variable order 1≤α(t)<2), respectively. The basic idea is to apply local discontinuous Galerkin method in space and a finite difference method in time. The stability and convergence analysis of the method are presented. Numerical results show that the accuracy and reliability of the proposed method for time-space fractional sine-Gordon equation.

Numerical Solution of Fractional Sine-Gordon Equation Using Spectral Method and Homogenization

AbstractIn this paper, a new method for the numerical solution of fractional sine-Gordon (SG) equation is presented. Our method consists of two steps, in first step: the main equation is converted to a homogeneous one using interpolation. In second step: two-dimensional approximation of functions by shifted Jacobi polynomials is used to reduce the problem into a system of nonlinear algebraic equations. The archived system is solved by Newton’s iterative method. Our method is stated in general case on rectangular [a,b] × [0,T] which is based upon Jacobi polynomial by parameters (α,β). Several test problems are employed and results of numerical experiments are presented and also compared with analytical solutions. Also, we verify the numerical stability of the method, by applying a disturbance in the problem. The obtained results confirm the acceptable accuracy and stability of the presented method.

Solutions of local fractional sine-Gordon equations

ABSTRACTIn this paper, we study sine-Gordon equation in order to obtain exact solitary wave solutions in the domain of fractional calculus. By using the definition of conformable fractional derivative, we obtain analytical solutions of time, space and time-space fractional sine-Gordon equations. We analyze graphically the effect of fractional order on evolution of the kink and antikink type solitons.

Reel Mertebeli Sine-Gordon Denklemlerinin Yaklaşık Soliton Çözümleri

In this study, the fractional Sine-Gordon (SG) equations (time-fractional, space-fractional and timespace- fractional) are solved using Homotopy Perturbation Method (HPM). The crucial point is the attained remarkable result from these solutions. While the solutions of classical and time-fractional SG equations are kink of type (Although of being the same type, they are different from each other), solution of the space-fractional SG equation is breather of type i.e., different types of soliton solutions are obtained using similar initial conditions for time and space fractional SG equation. Also these results show that some events such as vortex-antivortex couples in a Josephson junction or losses in signal dispersion of fiber optics communication can be modelled by fractional SG equations. In other words, this study may be very important for bringing to light the real behaviour of physical systems which have usually been described by classical SG equation. Because some physical events such as the memory effects of non-Markovian processes, the effects of non-Gaussian distribution, interactions between the systems and environment and some physical losses in the systems which are neglected in classical SG equation can be taken into account with fractional SG equations.