Positive definiteness of real quadratic forms resulting from the variable-step L1-type approximations of convolution operators

HL Liao, T Tang, T Zhou - Science China Mathematics, 2024 - Springer
The positive definiteness of real quadratic forms with convolution structures plays an
important role in stability analysis for time-stepping schemes for nonlocal operators. In this …

A second-order fitted scheme combined with time two-grid technique for two-dimensional nonlinear time fractional telegraph equations involving initial singularity

C Ou, Z Wang, S Vong - Journal of Computational and Applied …, 2024 - Elsevier
In this paper, we derive the improved regularity for two-dimensional nonlinear time fractional
telegraph equations by virtue of the technic of decomposition at first. Then, the famous L 2-1 …

Second-order non-uniform and fast two-grid finite element methods for non-linear time-fractional mobile/immobile equations with weak regularity

Z Tan - Applied Mathematics and Computation, 2025 - Elsevier
This paper introduces a novel temporal second-order fully discrete approach of finite
element method (FEM) and its fast two-grid FEM on non-uniform meshes, which aims to …

Asymptotically compatible energy of variable-step fractional BDF2 scheme for the time-fractional Cahn–Hilliard model

H Liao, N Liu, X Zhao - IMA Journal of Numerical Analysis, 2024 - academic.oup.com
A novel discrete gradient structure of the variable-step fractional BDF2 formula
approximating the Caputo fractional derivative of order is constructed by a local-nonlocal …

A fast algorithm for multi-term time-space fractional diffusion equation with fractional boundary condition

Z Lu, W Fan - Numerical Algorithms, 2024 - Springer
In this paper, the multi-term time-space fractional diffusion equation with fractional boundary
conditions is considered. The fractional derivative in space is approximated by the standard …

A unified design of energy stable schemes with variable steps for fractional gradient flows and nonlinear integro-differential equations

R Qi, X Zhao - SIAM Journal on Scientific Computing, 2024 - SIAM
A unified discrete gradient structure of the second order nonuniform integral averaged
approximations for the Caputo fractional derivative and the Riemann–Liouville fractional …

On the completely positive kernels for nonuniform meshes

Y Feng, L Li - arXiv preprint arXiv:2310.00972, 2023 - arxiv.org
The complete positivity, ie, positivity of the resolvent kernels, for convolutional kernels is an
important property for the positivity property and asymptotic behaviors of Volterra equations …

A finite difference method for solving the wave equation with fractional damping

M Cui, CC Ji, W Dai - Mathematical and Computational Applications, 2023 - mdpi.com
In this paper, we develop a finite difference method for solving the wave equation with
fractional damping in 1D and 2D cases, where the fractional damping is given based on the …

Variable-step numerical schemes and energy dissipation laws for time fractional Cahn–Hilliard model

R Qi, W Zhang, X Zhao - Applied Mathematics Letters, 2024 - Elsevier
Two temporal second-order energy stable schemes with variable time step sizes are
constructed for the time fractional Cahn–Hilliard model. Nonuniform L1+ formula is utilized …

An α-robust and new two-grid nonuniform L2-1σ FEM for nonlinear time-fractional diffusion equation

Z Tan - Computers & Mathematics with Applications, 2024 - Elsevier
This paper constructs and analyzes an α-robust and new two-grid finite element method
(FEM) with nonuniform L2-1 σ formula and its fast algorithms for nonlinear time-fractional …