17 citations · 20 across the 2 of their papers we have counts for
2 papers
math-ph2010★ 3 cited
Simplicity of extremal eigenvalues of the Klein-Gordon equation
Mario Koppen, Christiane Tretter, Monika Winklmeier
We consider the spectral problem associated with the Klein-Gordon equation for unbounded electric potentials. If the spectrum of this problem is contained in two disjoint real inte…
math-ph2009★ 17 cited
On the Ehrenfest theorem of quantum mechanics
Gero Friesecke, Mario Koppen
We give a mathematically rigorous derivation of Ehrenfest's equations for the evolution of position and momentum expectation values, under general and natural assumptions which inc…