Basic Quantum Theory and Measurement from the Viewpoint of Local Quantum Physics

TL;DR

This paper explores how local quantum physics (LQP) extends traditional quantum theory by linking causality to modular theory, revealing insights into antiparticles, charge superselection, and symmetries beyond standard quantum field theory.

Contribution

It highlights the unique aspects of LQP that go beyond standard quantum theory and Lagrangian methods, especially regarding causality and symmetry structures.

Findings

Causality in LQP relates to modular Tomita-Takesaki theory.

LQP reveals properties like antiparticles and charge superselection.

Connections between causality and internal symmetries are established.

Abstract

Several aspects of the manifestation of the causality principle in LQP (local quantum physics) are reviewed or presented. Particular emphasis is given to those properties which are typical for LQP in the sense that they do go beyond the structure of general quantum theory and even escape the Lagrangian quantization methods of standard QFT. The most remarkable are those relating causality to the modular Tomita-Takesaki theory, since they bring in the basic concepts of antiparticles, charge superselections as well as internal and external (geometric and hidden) symmetries.