Dirac equation Green’s function Hilbert-space geometry near EPs Klein–Gordon equation Klein–Gordon oscillator Proca equation classical and quantum mechanics classical general relativity contact potentials curved space degenerate perturbation theory infinite square well localization n/a non-Hermitian quantum dynamics position-dependent mass power-law duality quantum mechanics quark confinement relativistic wave equation scattering self-adjoint extensions semiclassical quantization semiclassical theories and applications shape invariance spreading wave function supersymmetric quantum mechanics supersymmetry thema EDItEUR::G Reference, Information and Interdisciplinary subjects::GP Research and information: general thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TB Technology: general issues