Thursday, May 24, 2012

INTERNAL, EXTERNAL AND GENERALIZED SYMMETRIES

External symmetry in general relativity

Ion I. Cotaescu (The West University of Timişoara, Romania)
We propose a generalization of the isometry transformations to the geometric context of the field theories with spin where the local frames are explicitly involved. We define the external symmetry transformations as isometries combined with suitable tetrad gauge transformations and we show that these form a group which is locally isomorphic with the isometry one. We point out that the symmetry transformations that leave invariant the equations of the fields with spin have generators with specific spin terms which represent new physical observables. The examples we present are the generators of the central symmetry and those of the maximal symmetries of the de Sitter and anti-de Sitter spacetimes derived in different tetrad gauge fixings. 
Pacs: 04.20.Cv, 04.62.+v, 11.30.-j
Comments: 25 pages, Latex
Subjects: General Relativity and Quantum Cosmology (gr-qc)
Journal reference:J.Phys.A33:9177-9192,2000
DOI: 10.1088/0305-4470/33/50/304
Cite as:arXiv:gr-qc/0005135v1


Groupoids: Unifying Internal and External Symmetry

作者:A Weinstein - 1996 - 被引用次数:170 - 相关文章
Groupoids: Unifying Internal and ExternalSymmetry. A Tour through Some Examples. Alan Weinstein. 744. NOTICES OF THE AMS. VOLUME 43, NUMBER 7 ...



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INTERNAL, EXTERNAL AND GENERALIZED SYMMETRIES

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作者:IM Anderson - 1990 - 被引用次数:54 - 相关文章
ones which do not come from classical "externalsymmetries... external symmetry of a system of differential equations gives rise to an internal symmetry ...


About the Origin of the Division between Internal and External Symmetries in Quantum Field Theory

It is made the attempt to explain why there exists a division between internal symmetries referring to quantum numbers and external symmetries referring to space-time within the description of relativistic quantum field theories. It is hold the attitude that the symmetries of quantum theory are the origin of both sorts of symmetries in nature. Since all quantum states can be represented as a tensor product of two dimensional quantum objects, called ur objects, which can be interpreted as quantum bits of information, described by spinors reflecting already the symmetry properties of space-time, it seems to be possible to justify such an attitude. According to this, space-time symmetries can be considered as a consequence of a representation of quantum states by quantum bits. Internal symmetries are assumed to refer to relations of such fundamental objects, which are contained within the state of one single particle, with respect to each other. In this sense the existence of space-time symmetries, the existence of internal symmetries and their division could obtain a derivation from quantum theory interpreted as a theory of information.
Comments:5 pages
Subjects:General Physics (physics.gen-ph)
Cite as: arXiv:0910.3303v1 [physics.gen-ph]

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