Centrosymmetric Matrices in the Sinc Collocation Method for Sturm-Liouville Problems
This work provides a computational efficiency improvement for solving a class of eigenvalue problems, but it is incremental as it applies known matrix properties to a specific numerical method.
The authors show that for Sturm-Liouville problems whose operator commutes with the parity operator, the Sinc collocation method yields centrosymmetric matrices, enabling the decomposition of one large eigensystem into two smaller ones. This reduces computational and storage requirements to 1/(N+1) of all components, with numerical results for the anharmonic potential demonstrating substantial gains in efficiency and accuracy.
Recently, we used the Sinc collocation method with the double exponential transformation to compute eigenvalues for singular Sturm-Liouville problems. In this work, we show that the computation complexity of the eigenvalues of such a differential eigenvalue problem can be considerably reduced when its operator commutes with the parity operator. In this case, the matrices resulting from the Sinc collocation method are centrosymmetric. Utilizing well known properties of centrosymmetric matrices, we transform the problem of solving one large eigensystem into solving two smaller eigensystems. We show that only 1/(N+1) of all components need to be computed and stored in order to obtain all eigenvalues, where (2N+1) corresponds to the dimension of the eigensystem. We applied our result to the Schrödinger equation with the anharmonic potential and the numerical results section clearly illustrates the substantial gain in efficiency and accuracy when using the proposed algorithm.