Results 271 to 280 of about 25,446 (301)

Internal and Space-Time Symmetries

Physical Review, 1965
To account for the observed multiplet structure and the mass relations among the known elementary particles, a coupling of internal and space-time properties is considered. Earlier attempts in this direction have failed. The problem is re-examined from a more general point of view, and it is found that under these more relaxed conditions a coupling is ...
Ottoson, U., Kihlberg, A., Nilsson, Jan
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Symmetries of self-dual Yang-Mills equations dimensionally reduced from (2, 2) space-time

Journal of High Energy Physics, 2011
We construct infinite-dimensional symmetries of the two dimensional equation which results from the dimensional reduction of the self-duality condition in (2, 2) signature space-time.
Paul Mansfield
exaly   +3 more sources

Concerning Space-Time and Symmetry Groups

Physical Review, 1964
Several theorems are proved which exhibit the impossibility of constructing nontrivial products of the Lorentz group with internal symmetry groups for some physically interesting examples. It is also shown that if the Lorentz group is replaced by the Galilei group, qualitatively different results are obtained; a "linear" breakdown of internal symmetry ...
Mayer, M. E., Schnitzer, H. J., Sudarshan, E. C. G., Acharya, R., Han, M. Y.   +4 more
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Fluid space–times and conharmonic symmetries

Journal of Mathematical Physics, 1998
The conharmonic curvature tensor is considered as an invariant of the conharmonic transformation defined by Ishii and the necessary and sufficient conditions for the conharmonic curvature tensor in a perfect fluid space–time to be divergence free has been obtained. Conharmonic motion, conharmonic collineation, and conharmonic curvature collineation are
Abdussattar, Dwivedi, Babita
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ON LOCAL CURVATURE SYMMETRIES OF GRW SPACE-TIMES

Reports on Mathematical Physics, 2021
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
De, Uday Chand, Shenawy, Sameh
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Invariant Approach to a Space-Time Symmetry

Journal of Mathematical Physics, 1971
A study is made of Killing vector fields in vacuum Einstein spaces with a restriction primarily to those fields whose associated bivector is nonnull. However, a well-known theorem of Robinson is modified slightly to show that if such a space admits a null bivector associated with a Killing vector, the space must be algebraically special.
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Symmetries of Space-Time

2019
Abstract This chapter discusses preliminary concepts needed for the book: relativity and relativistic kinematics, natural units, elements of group theory, discrete symmetries of space ...
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Internal-Symmetry Groups and Curved Space-Time

Physical Review, 1965
Some theorems are proved which exhibit the impossibility of constructing nontrivial products of the 3+2 de Sitter group with internal-symmetry groups (under physically reasonable assumptions). It is shown that either mass degeneracy, $[{E}_{\ensuremath{\alpha}},{P}_{\ensuremath{\mu}}]=0$, or simultaneous measurement of internal quantum numbers and ...
Acharya, R., Narayanaswamy, P.
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Macroscopic symmetry in space-time

Reports on Progress in Physics, 1963
Magnetic and non-magnetic crystallographic point groups may be distinguished by the different relations in which they stand to the time-inversion or anti-identity operator R. The 32 point groups of classical crystallography G may be used to generate both magnetic and non-magnetic groups.
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Coupling of Space-Time and Internal Symmetry

Fortschritte der Physik, 1968
Hegerfeldt, G. C., Hennig, J.
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