23 citations · 24 across the 8 of their papers we have counts for
8 papers
Remarks to the Resonance-Decay Problem in Quantum Mechanics from a mathematical point of view
Hellmut Baumgärtel
The description of bumps in scattering cross-sections by Breit-Wigner amplitudes led in the framework of the mathematical Physics to its formulation as the so-called Resonance-Deca…
On the border lines between the regions of distinct solution type for solutions of the Friedmann equation satisfying the Hubble condition
Hellmut Baumgärtel
It is well-known that there are four distinct basic types (two Big Bang types, Lemaitre and Big Crunch type) for solutions of the general Friedmann equation with positive cosmologi…
On the frontier lines between the regions of invariant solution type for solutions of the Friedmann equation satisfying the Hubble condition
Hellmut Baumgärtel
It is well-known that there are four distinct basic types (two BigBang types, Lemaitre and BigCrunch type) for solutions of the general Friedmann equation with positive cosmologica…
The general Friedmann equation: a mathematical point of view
Hellmut Baumgärtel
The note presents a classification of the relevant distinct types of solutions of the general Friedmann equation without assuming a priori restrictions for the parameters occurring…
Decay Semigroups for the Resonances of Quantum Mechanical Scattering Systems
Hellmut Baumgärtel
For selected classes of quantum mechanical Hamiltonians a canonical association of a decay semigroup is presented. The spectrum of the generator of this semigroup is a pure eigenva…
The eigenvalue problem for the resonances of the infinite-dimensional Friedrichs model on the positive half line with Hilbert-Schmidt perturbations
Hellmut Baumgärtel
A Gelfand triplet for the Hamiltonian H of the infinite-dimensional Friedrichs model on the positive half line with Hilbert-Schmidt perturbations is constructed such that exactly t…