Über den Grundzustand überschwerer Atome
We consider a bound relativistic electron in a Coulomb-Field with charge numbers greater than 137. By careful examination of the self-adjointness property of the Hamiltonian we determine the energy eigenvalues; they depend on a parameter which can be interpreted as a cut-off radius of the potential leading to quantitative predictions of the energy of the spectrum, especially of the lowest state.