منابع مشابه
Broken Symmetry and Spacetime
The phenomenon of broken spacetime symmetry in the quantum theory of infinite systems seems to point toward an unorthodox ontology. The standard conception of the physical meaning of these symmetries, as changes in coordinates, conflicts with the apparent physical inequivalence of symmetry-related states. I argue that this apparent conflict is an artifact a subtle error in the extant account of...
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Goldstone's theorem states that there is a massless mode for each broken symmetry generator. It has been known for a long time that the naive generalization of this counting fails to give the correct number of massless modes for spontaneously broken spacetime symmetries. We explain how to get the right count of massless modes in the general case, and discuss examples involving spontaneously bro...
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A fundamental problem in the theory of PT-invariant quantum systems is to determine whether a given system “respects” this symmetry or not. If not, the system usually develops non-real eigenvalues. It is shown in this contribution how to algorithmically detect the existence of complex eigenvalues for a given PT-symmetric matrix. The procedure uses classical results from stability theory which q...
متن کاملSymmetry-seeking spacetime coordinates
One of the fundamental problems in numerically constructing spacetimes without symmetries (3D numerical relativity) is the choice of suitable coordinates. The task is not just to find a good coordinate system for a known spacetime, but the spacetime is not actually known when the calculation begins, so that one has to construct the coordinate system along with the spacetime. In principle, once ...
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Supersymmetric models with Lorentz violation can be formulated in super-space. Two theories based on the Wess-Zumino model are discussed. A com-pactification of superspace can be employed to understand the chiral superfield that arises in the models.
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ژورنال
عنوان ژورنال: Philosophy of Science
سال: 2011
ISSN: 0031-8248,1539-767X
DOI: 10.1086/658112