Causality in relativistic many body theory

Causality in Relativistic Many Body Theory

Dirac sea effects are perhaps the most interesting characteristic of relativistic many body theory. In nuclear matter e.g. the effective mass of the nucleons and their coupling to the mesons undergo considerable corrections due to vacuum fluctuations [1], [2]. In addition, relativistic many body theory predicts strong corrections of the properties of hadrons at high nuclear matter densities. Un...

Nonequilibrium Relativistic Quantum Many-Body Theory

Relativistic Hamiltonians in many-body theories.

We discuss the description of a many-body nuclear system using Hamilto-nians that contain the nucleon relativistic kinetic energy and potentials with relativistic corrections. Through the Foldy-Wouthuysen transformation, the field theoretical problem of interacting nucleons and mesons is mapped to an equivalent one in terms of relativistic potentials, which are then expanded at some order in 1/...

Many Body Theory

We study theoretically the spin response functions using the relativistic many body theory. The spin response functions in the relativistic theory are reduced largely from the ones of the non-relativistic theory. This happens particularly to the longitudinal spin responses. This fact is able to remove the difficulty in reproducing the ratio of the longitudinal and transverse response functions ...

Remarks on Causality in Relativistic Quantum Field Theory

It is shown that the correlations predicted by relativistic quantum field theory in locally normal states between projections in local von Neumann algebras A(V1),A(V2) associated with spacelike separated spacetime regions V1, V2 have a (Reichenbachian) common cause located in the union of the backward light cones of V1 and V2. Further comments on causality and independence in quantum field theo...