4 papers
Structure-preserving preconditioning of discrete space-fractional diffusion equations with variable coefficient and θ-Method
Muhammad Faisal Khan, Asim Ilyas, Rolf Krause +2
This paper studies the spectral properties of large matrices and the preconditioning of linear systems, arising from the finite difference discretization of a time-dependent space-…
Symbol-based multilevel block preconditioners for multilevel block Toeplitz systems: GLT-based analysis and applications
Sean Y. Hon, Congcong Li, Rosita L. Sormani +2
In recent years, there has been a renewed interest in preconditioning for multilevel Toeplitz systems, a research field that has been extensively explored over the past several dec…
Asymptotic spectral properties and preconditioning of an approximated nonlocal Helmholtz equation with Caputo fractional Laplacian and variable coefficient wave number
Andrea Adriani, Rosita Luisa Sormani, Cristina Tablino-Possio +2
The current study investigates the asymptotic spectral properties of a finite difference approximation of nonlocal Helmholtz equations with a Caputo fractional Laplacian and a vari…
Fractional differential problems with numerical anti-reflective boundary conditions: a computational/precision analysis and numerical results
ErcÃlia Sousa, Cristina Tablino-Possio, Rolf Krause +1
Twenty years ago the anti-reflective numerical boundary conditions (BCs) were introduced in a context of signal processing and imaging, for increasing the quality of the reconstruc…