A New Legendre Spectral Galerkin and Pseudo-Spectral Approximations for Fractional Initial Value Problems

الملخص EN

We extend the application of the Galerkin method for treating the multiterm fractional differential equations (FDEs) subject to initial conditions.

A new shifted Legendre-Galerkin basis is constructed which satisfies exactly the homogeneous initial conditions by expanding the unknown variable using a new polynomial basis of functions which is built upon the shifted Legendre polynomials.

A new spectral collocation approximation based on the Gauss-Lobatto quadrature nodes of shifted Legendre polynomials is investigated for solving the nonlinear multiterm FDEs.

The main advantage of this approximation is that the solution is expanding by a truncated series of Legendre-Galerkin basis functions.

Illustrative examples are presented to ensure the high accuracy and effectiveness of the proposed algorithms are discussed.