Konsep Inti
The WSBDF7 method, a stable linear combination of the unstable seven-step backward difference formula (BDF7) and its shifted counterpart, is constructed and analyzed for the discretization of parabolic equations with self-adjoint elliptic part.
Abstrak
The content discusses the construction and analysis of the Weighted and Shifted Seven-Step Backward Difference Formula (WSBDF7) method for the discretization of parabolic equations with self-adjoint elliptic part.
Key highlights:
The seven-step BDF method and its shifted counterpart are not zero-stable, but their linear combination, the WSBDF7 method, is shown to be A(ϕ)-stable for a suitable weight parameter ϑ = 3.
Suitable multipliers are determined for the WSBDF7 method, and stability is established using the energy technique.
The stability regions of the WSBDF7 methods increase as the weight parameter ϑ increases, and are larger than the stability regions of the classical BDF methods of the same order.
The proposed approach is applicable for a variety of parabolic equations, including mean curvature flow, gradient flows, fractional equations, and nonlinear equations.