RT info:eu-repo/semantics/article T1 Spectral properties of the two-dimensional Schrödinger Hamiltonian with various solvable confinements in the presence of a central point perturbation A1 Fassari, Silvestro A1 Gadella Urquiza, Manuel A1 Glasser, M. Lawrence A1 Nieto Calzada, Luis Miguel A1 Rinaldi, F. AB We study three solvable two-dimensional systems perturbed by a point interaction centered at theorigin. The unperturbed systems are the isotropic harmonic oscillator, a square pyramidalpotential and a combination thereof. We study the spectrum of the perturbed systems. We showthat, while most eigenvalues are not affected by the point perturbation, a few of them are stronglyperturbed. We show that for some values of one parameter, these perturbed eigenvalues may takelower values than the immediately lower eigenvalue, so that level crossings occur. These levelcrossings are studied in some detail. SN 0031-8949 YR 2019 FD 2019 LK http://uvadoc.uva.es/handle/10324/40850 UL http://uvadoc.uva.es/handle/10324/40850 LA spa NO Physica Scripta, 2019, vol. 94 DS UVaDOC RD 23-nov-2024