3 papers
quant-ph2026
Entanglement of quantum systems via a classical mediator in hybrid van Hove theory
Sebastian Ulbricht, Andrés DarÃo 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…
gr-qc2025
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…
quant-ph2025
Classical and mixed classical-quantum systems from van Hove's unitary representation of contact transformations
Marcel Reginatto, Andrés DarÃo 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…