High frequency wave packets for the Schrödinger equation and its numerical approximations
This work addresses the numerical analysis community by illustrating the behavior of high-frequency wave packets under bigrid filtering, but it is an incremental extension of known results.
The paper constructs Gaussian wave packets for the linear Schrödinger equation and its finite difference discretization, demonstrating the lack of uniform dispersive properties in numerical solutions. It numerically analyzes how bigrid filtering mechanisms affect the splitting and propagation of these high-frequency wave packets.
We build Gaussian wave packets for the linear Schrödinger equation and its finite difference space semi-discretization and illustrate the lack of uniform dispersive properties of the numerical solutions as established in Ignat, Zuazua, Numerical dispersive schemes for the nonlinear Schrödinger equation, SIAM. J. Numer. Anal., 47(2) (2009), 1366-1390. It is by now well known that bigrid algorithms provide filtering mechanisms allowing to recover the uniformity of the dispersive properties as the mesh size goes to zero. We analyze and illustrate numerically how these high frequency wave packets split and propagate under these bigrid filtering mechanisms, depending on how the fine grid/coarse grid filtering is implemented.