5 citations · 11 across the 7 of their papers we have counts for
7 papers
Friedmann equation and SCP-results
Hellmut Baumgaertel
This note emphasizes that only special solutions of the Friedmann equation are compatible with the results of the "Supernovae Cosmology Project" (SCP). The curvature parameter of t…
Remarks related to the paper of Rafael de la Madrid: "On the inconsistency of the Bohm-Gadella theory with quantum mechanics", JPhysA 39, No. 29, 9255-9268 (2006)
Hellmut Baumgaertel
The paper contains critical comments to the paper mentioned in the title from the mathematical point of view
On Lax-Phillips semigroups
Hellmut Baumgaertel
Lax-Phillips evolutions are described by two-space scattering systems. The canonical identification operator is characterized for Lax-Phillips evolutions, whose outgoing and incomi…
Superselection in the presence of constraints
Hellmut Baumgaertel, Hendrik Grundling
For systems which contain both superselection structure and constraints, we study compatibility between constraining and superselection. Specifically, we start with a generalisatio…
An application of the DR-duality theory for compact groups to endomorphism categories of C*-algebras with nontrivial center
Hellmut Baumgaertel, Fernando Lledo
In Rev. Math. Phys. 4 (1997) 785 we study Hilbert-C* systems {F,G} where the fixed point algebra A has nontrivial center Z and where A'\cap F=Z is satisfied. The corresponding cate…
Hilbert C*-systems for actions of the circle group
H. Baumgaertel, A. L. Carey
The paper contains constructions of Hilbert systems for the action of the circle group using subgroups of implementable Bogoljubov unitaries w.r.t. Fock representations of the…