59 research outputs found
Dynamical locality and covariance: What makes a physical theory the same in all spacetimes?
The question of what it means for a theory to describe the same physics on
all spacetimes (SPASs) is discussed. As there may be many answers to this
question, we isolate a necessary condition, the SPASs property, that should be
satisfied by any reasonable notion of SPASs. This requires that if two theories
conform to a common notion of SPASs, with one a subtheory of the other, and are
isomorphic in some particular spacetime, then they should be isomorphic in all
globally hyperbolic spacetimes (of given dimension). The SPASs property is
formulated in a functorial setting broad enough to describe general physical
theories describing processes in spacetime, subject to very minimal
assumptions. By explicit constructions, the full class of locally covariant
theories is shown not to satisfy the SPASs property, establishing that there is
no notion of SPASs encompassing all such theories. It is also shown that all
locally covariant theories obeying the time-slice property possess two local
substructures, one kinematical (obtained directly from the functorial
structure) and the other dynamical (obtained from a natural form of dynamics,
termed relative Cauchy evolution). The covariance properties of relative Cauchy
evolution and the kinematic and dynamical substructures are analyzed in detail.
Calling local covariant theories dynamically local if their kinematical and
dynamical local substructures coincide, it is shown that the class of
dynamically local theories fulfills the SPASs property. As an application in
quantum field theory, we give a model independent proof of the impossibility of
making a covariant choice of preferred state in all spacetimes, for theories
obeying dynamical locality together with typical assumptions.Comment: 60 pages, LaTeX. Version to appear in Annales Henri Poincar
Die Wirkungsweise von Vanadylpyrophosphat-Katalysatoren. Teilprojekt: Reaktionsmechanismus Abschlussbericht
SIGLEAvailable from TIB Hannover: F98B1838+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman
The Use of Antibiotic-impregnated Cement in Infected Reconstructions after Resection for Bone Tumors
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