26 research outputs found
The second law of thermodynamics, TCP, and Einstein causality in anti-de Sitter space-time
If the vacuum is passive for uniformly accelerated observers in anti-de
Sitter space-time (i.e. cannot be used by them to operate a "perpetuum
mobile"), they will (a) register a universal value of the Hawking-Unruh
temperature, (b) discover a TCP symmetry, and (c) find that observables in
complementary wedge-shaped regions are commensurable (local) in the vacuum
state. These results are model independent and hold in any theory which is
compatible with some weak notion of space-time localization.Comment: 8 pages, slightly improved results, minor changes in the expository
part, new title; to appear in "Classical and Quantum Gravity
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 \cA(V_1),\cA(V_2) associated with spacelike separated spacetime
regions have a (Reichenbachian) common cause located in the union of
the backward light cones of and . Further comments on causality and
independence in quantum field theory are made.Comment: 10 pages, Latex, Quantum Structures 2002 Conference Proceedings
submission. Minor revision of the order of definitions on p.
Infraparticles with superselected direction of motion in two-dimensional conformal field theory
Particle aspects of two-dimensional conformal field theories are
investigated, using methods from algebraic quantum field theory. The results
include asymptotic completeness in terms of (counterparts of) Wigner particles
in any vacuum representation and the existence of (counterparts of)
infraparticles in any charged irreducible product representation of a given
chiral conformal field theory. Moreover, an interesting interplay between the
infraparticle's direction of motion and the superselection structure is
demonstrated in a large class of examples. This phenomenon resembles the
electron's momentum superselection expected in quantum electrodynamics.Comment: 34 pages, no figure. The final version is available under Open
Access. CC-B
A Method for Evaluating Transmission Line Magnetic Field Mitigation Strategies That Incorporates Biological Uncertainty
A method to determine how much reduction in public exposure to power frequency magnetic fields can be obtained for different levels of investment is presented. Which if any âeffects functionâ best describes the relationship between field exposure and biological effect is uncertain at this time. Also, in a particular context such as construction of new transmission lines there are a variety of different technologies which might be used to reduce exposure. We describe and demonstrate a method by which exposure reduction supply curves (i.e., the cost of purchasing different amounts of exposure reduction given various mitigation options) can be estimated parametrically for different exposure conditions and effects functions, and we display illustrative results
When are quantum systems operationally independent?
We propose some formulations of the notion of "operational independence" of two subsystems S1,S2 of a larger quantum system S and clarify their relation to other independence concepts in the literature. In addition, we indicate why the operational independence of quantum subsystems holds quite generally, both in nonrelativistic and relativistic quantum theory