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Bert Schroer

Publications and source records attributed to Bert Schroer.

78 records · Page 5Linked to original sources

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

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.

quant-ph↗

The Pivotal Role of Causality in Local Quantum Physics

In this article an attempt is made to present very recent conceptual and computational developments in QFT as new manifestations of old and well establihed physical principles. The vehicle for converting the quantum-algebraic aspects of local quantum physics into more classical geometric structures is the modular theory of Tomita. As the above named laureate to whom I have dedicated has shown together with his collaborator for the first time in sufficient generality, its use in physics goes through Einstein causality. This line of research recently gained momentum when it was realized that it is not only of structural and conceptual innovative power (see section 4), but also promises to be a new computational road into nonperturbative QFT (section 5) which, picturesquely speaking, enters the subject on the extreme opposite (noncommutative) side.

hep-th↗

Modular Wedge Localization and the d=1+1 Formfactor Program

In this paper I continue the study of the new framework of modular localization and its constructive use in the nonperturbative d=1+1 Karowski-Weisz-Smirnov formfactor program. Particular attention is focussed on the existence of semilocal generators of the wedge-localized algebra without vauum polarization (FWG-operators) which are closely related to objects fulfilling the Zamolodchikov-Faddeev algebraic structure. They generate a ``thermal Hilbert space'' and allow to understand the equivalence of the KMS conditions with the so-called cyclicity equation for formfactors which was known to be closely related to crossing symmetry properties. The modular setting gives rise to interesting new ideas on ``free'' d=2+1 anyons and plektons.

hep-th↗

Modular Localization, H-Temperatures and the Bethe Ansatz Structure

The recently proposed constructive approach to nonperturbative QFT, based on modular localization, is reviewed and extended. It allows to unify black holes physics and H-temperatures (H standing for Hawking or Horizon) with the bootstrap-formfactor program for nonperturbative construction of low dimensional QFT. In case of on-shell particle number conservation, the equations characterizing the modular localization spaces for wedges are Bethe-Ansatz equation in the form as recently obtained in the treatment of factorizable models.

hep-th↗