×

Isospectral domains for discrete elliptic operators. (English) Zbl 1397.65223

Summary: Concerning the Laplace operator with homogeneous Dirichlet boundary conditions, the classical notion of isospectrality assumes that two domains are related when they give rise to the same spectrum. In two dimensions, non isometric, isospectral domains exist. It is not known however if all the eigenvalues relative to a specific domain can be preserved under suitable continuous deformation of its geometry. We show that this is possible when the 2D Laplacian is replaced by a finite dimensional version and the geometry is modified by respecting certain constraints. The analysis is carried out in a very small finite dimensional space, but it can be extended to more accurate finite-dimensional representations of the 2D Laplacian, with an increase of computational complexity. The aim of this paper is to introduce the preliminary steps in view of more serious generalizations.

MSC:

65N06 Finite difference methods for boundary value problems involving PDEs
35J05 Laplace operator, Helmholtz equation (reduced wave equation), Poisson equation
35J25 Boundary value problems for second-order elliptic equations
65J10 Numerical solutions to equations with linear operators

References:

[1] Arendt, W.; Nittka, R.; Peter, W.; Steiner, F.; Arendt, W. (ed.); Schleich, WP (ed.), Spectral properties of the Laplacian in mathematics and physics (2009), Weinheim · Zbl 1159.94001 · doi:10.1002/9783527628025
[2] Buser, P., Conway, J., Doyle, P., Semmler, K.-D.: Some planar isospectral domains. Int. Math. Res. Not. 9, 391-400 (1994) · Zbl 0837.58033 · doi:10.1155/S1073792894000437
[3] Chapman, S.J.: Drums that sound the same. Am. Math. Mon. 102, 124-138 (1995) · Zbl 0849.35084 · doi:10.2307/2975346
[4] Codeluppi, A.: Quadrilateri isospettrali per un operatore in dimensione finita, Thesis, Università di Modena e Reggio Emilia (2013) · Zbl 0139.05603
[5] Deift, P., Nanda, T., Tomei, C.: Ordinary differential equations and the symmetric eigenvalue problem. SIAM J. Numer. Anal. 20(1), 1-22 (1983) · Zbl 0526.65032 · doi:10.1137/0720001
[6] Flaschka, H.: The Toda lattice, I. Phys. Rev. B 9, 1924-1925 (1974) · Zbl 0942.37504 · doi:10.1103/PhysRevB.9.1924
[7] Funaro, D.: Spectral Elements for Transport-Dominated Equations. Lecture Notes in Computational Science and Engineering, vol. 1. Springer, New York (1997) · Zbl 0891.65118
[8] Gordon, C., Webb, D., Wolpert, S.: Isospectral plane domains and surfaces via Riemannian orbifolds. Inv. Math. 110(1), 11-22 (1993) · Zbl 0778.58068
[9] Grebenkov, D.S., Nguyen, B.-T.: Geometrical structure of Laplacian eigenfuncions. SIAM Rev. 55(4), 601-667 (2013) · Zbl 1290.35157 · doi:10.1137/120880173
[10] Henry, D.: Perturbation of the Boundary in Boundary-Value Problems of Partial Differential Equations. Cambridge University Press, Cambridge (2005) · Zbl 1170.35300 · doi:10.1017/CBO9780511546730
[11] Kac, M.: Can one hear the shape of a drum? Am. Math. Mon. 73, 1-23 (1966) · Zbl 0139.05603 · doi:10.1080/00029890.1966.11970915
[12] Rudin, W.: Principles of Mathematical Analysis. McGraw-Hill, New York (1976) · Zbl 0346.26002
[13] Sunada, T.: Riemannian coverings and isospectral manifolds. Ann. Math. 121, 169-186 (1985) · Zbl 0585.58047 · doi:10.2307/1971195
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.