How the modified Bertrand theorem explains regularities of the periodic table I. From conformal invariance to Hopf mapping

Arkady L. Kholodenko, Louis H. Kauffman

Bertrand theorem permits closed orbits in 3d Euclidean space only for 2 types of central potentials. These are of Kepler-Coulomb and harmonic oscillator type. Volker Perlick recent…