arXiv subjects

Emmanuel Asante-Asamani

Publications and source records attributed to Emmanuel Asante-Asamani.

2 recordsLinked to original sources

arXiv2025

A fourth-order exponential time differencing scheme with real and distinct poles rational approximation for solving non-linear reaction-diffusion systems

A fourth-order, L-stable, exponential time differencing Runge-Kutta type scheme is developed to solve nonlinear systems of reaction diffusion equations with nonsmooth data. The new scheme, ETDRK4RDP, is constructed by approximating the matrix exponentials in the ETDRK4 scheme with a fourth order, L-acceptable, non-Padé rational function having real and distinct poles (RDP). Using RDP rational functions to construct the scheme ensures efficient damping of spurious oscillations arising from non-smooth initial and boundary conditions and a straightforward parallelization. We verify empirically that the new ETDRK4RDP scheme is fourth-order accurate for several reaction diffusion systems with Dirichlet and Neumann boundary conditions and show it to be more efficient than competing exponential time differencing schemes, especially when implemented in parallel, with up to six times speedup in CPU time.

math.NA↗

arXiv2023

A Robust Numerical Scheme for Solving Riesz-Tempered Fractional Reaction-Diffusion Equations

The Fractional Diffusion Equation (FDE) is a mathematical model that describes anomalous transport phenomena characterized by non-local and long-range dependencies which deviate from the traditional behavior of diffusion. Solving this equation numerically is challenging due to the need to discretize complicated integral operators which increase the computational costs. These complexities are exacerbated by nonlinear source terms, nonsmooth data and irregular domains. In this study, we propose a second order Exponential Time Differencing Finite Element Method (ETD-RDP-FEM) to efficiently solve nonlinear FDE, posed in irregular domains. This approach discretizes matrix exponentials using a rational function with real and distinct poles, resulting in an L-stable scheme that damps spurious oscillations caused by non-smooth initial data. The method is shown to outperform existing second-order methods for FDEs with a higher accuracy and faster computational time.

math.NA↗