title: On the description of subsystems in relativistic hypersurface Bohmian mechanics.
abstract: A candidate for a realistic relativistic quantum theory is the hypersurface Bohm-Dirac model. Its formulation uses a foliation of space-time into space-like hypersurfaces. In order to apply the theory and to make contact with the usual quantum formalism, one needs a framework for the description of subsystems. The presence of spin together with the foliation renders the subsystem description more complicated than in the non-relativistic case with spin. In this paper, we provide such a framework in terms of an appropriate conditional density matrix and an effective wave function as well as clarify their relation, thereby generalizing previous subsystem descriptions in the non-relativistic case.
authors.affiliation: Mathematisches Institut, Ludwig-Maximilians-Universität , Theresienstrasse 39, 80333 München, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Dürr
authors.affiliation: Mathematisches Institut, Ludwig-Maximilians-Universität , Theresienstrasse 39, 80333 München, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Lienert
keywords: Bohmian mechanics; Lorentz invariance; density matrices; multi-time wave functions; relativity theory; subsystem analysis