6 papers
Bypassing no-go theorems on mixed classical-quantum systems: the (counter)example of hybrid van Hove theory
Marcel Reginatto, Andrés Darío Bermúdez Manjarres, Sebastian Ulbricht
Motivated by models of mixed quantum-classical hybrid theories, we consider the representation of classical observables as Hilbert-space operators based on van Hove's unitary repre…
Entanglement of quantum systems via a classical mediator in hybrid van Hove theory
Sebastian Ulbricht, Andrés Darío Bermúdez Manjarres, Marcel Reginatto
It is a matter of ongoing discussion whether quantum states can become entangled while only interacting via a classical mediator. This lively debate is deeply interwoven with the q…
Classical and mixed classical-quantum systems from van Hove's unitary representation of contact transformations
Marcel Reginatto, Andrés Darío Bermúdez Manjarres, Sebastian Ulbricht
Descriptions of classical mechanics in Hilbert space go back to the work of Koopman and von Neumann in the 1930s. Decades later, van Hove derived a unitary representation of the gr…
Three statistical descriptions of classical systems and their extensions to hybrid quantum-classical systems
Andrés Darío Bermúdez Manjarres, Marcel Reginatto, Sebastian Ulbricht
We present three statistical descriptions for systems of classical particles and consider their extension to hybrid quantum-classical systems. The classical descriptions are ensemb…
A gravitational metrological triangle
Claus Lammerzahl, Sebastian Ulbricht
Motivated by the similarity of the mathematical structure of Einstein's General Relativity in its weak field limit and of Maxwell's theory of electrodynamics it is shown that there…
Einstein's basement - A kinematic sector complementing special relativity
Fritz Riehle, Sebastian Ulbricht
We revisit the concept of particles as it is used in special relativity. The presented model treats the energy-momentum relation of relativistic particles as the upper branch of a…