This paper presents an approximate method of solving the fractional (in the time variable) equation which describes the processes lying between heat and wave behavior. The approximation consists in the application of a finite subspace of an infinite basis in the time variable (Galerkin method) and discretization in space variables. In the final step, a large-scale system of linear equations wit...

We construct uniformly high order accurate discontinuous Galerkin (DG) schemes which preserve positivity of density and pressure for Euler equations of compressible gas dynamics. The same framework also applies to high order accurate finite volume (e.g. essentially nonoscillatory (ENO) or weighted ENO (WENO)) schemes. Motivated by [18, 24], a general framework, for arbitrary order of accuracy, ...

In this paper we show that wavelets can be used as basis functions for Galerkin methods. For differential equations, finite element or finite difference methods lead to matrices that are already shown to be sparse, but they tend to be ill-conditioned, [4]. In this paper, we show that wavelet basis gives sparse matrix with low condition number for Galerkin methods. Numerical examples are present...

How close are Galerkin eigenvectors to the best approximation available out of the trial subspace ? Under a variety of conditions the Galerkin method gives an approximate eigenvector that approaches asymptotically the projection of the exact eigenvector onto the trial subspace – and this occurs more rapidly than the underlying rate of convergence of the approximate eigenvectors. Both orthogonal...

We present a streamline diffusion shock capturing spacetime discontinuous Galerkin (DG) method to approximate nonlinear systems of conservation laws in several space dimensions. The degrees of freedom are in terms of the entropy variables and the numerical flux functions are the entropy stable finite volume fluxes. We show entropy stability of the (formally) arbitrarily high order accurate meth...

Article history: Received 27 January 2014 Received in revised form 22 October 2014 Accepted 26 October 2014 Available online 30 October 2014

A general theory is given for discretized versions of the Galerkin method for solving Fredholm integral equations of the second kind. The discretized Galerkin method is obtained from using numerical integration to evaluate the integrals occurring in the Galerkin method. The theoretical framework that is given parallels that of the regular Galerkin method, including the error analysis of the sup...

A parallel solvers package of three solvers with a unified user interface is developed for solving a range of sparse symmetric complex linear systems arising from disc~tization of partial differential equations based on unstructu~d meshs using finite element, finite difference and finite volume analysis. Once the data interface is set up, the package constructs the sparse symmetric complex matr...

Article history: Received 22 November 2012 Received in revised form 13 June 2014 Accepted 1 July 2014 Available online 8 July 2014