A rather strong concept of symmetry is introduced in classical mechanics, in the sense that some mechanical systems can be completely characterized by the symmetry laws
they obey. Accordingly, a ‘‘complete symmetry group’’ realization in
mechanics must be endowed with the following two features: (1) the group
acts freely and transitively on the manifold of all allowed motions of the system; (2) the given equations of motion are the only ordinary differential equations
that remain invariant under the specified action of the group. This
program is applied successfully to the classical Kepler problem, since
the complete symmetry group for this particular system is here obtained.
The importance of this result for the quantum kinematic theory of the Kepler system is emphasized.
REFERENCES
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Even contact transformations, involving the velocity as an independent
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but such transformations fail to produce a “complete symmetry group” in the sense required here. To take a case in point, contact transformations for the classical Kepler problem were studied by J. M. Levy-Leblond, Am. J. Phys. 39, 502 (1971), but they do not yield a complete group for this particular system. Google ScholarCrossref - 4. M. Aguirre and J. Krause, J. Math. Phys. 29, 9 (1988). , Google ScholarScitation
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however, it seems to be not so well known to most physicists. For instance, the rediscovery eighteen years ago by C. E. Wulfman and B. G. Wyborne, J. Phys. A 9, 507 (1976), that the equation of motion ẍ+ω2x = 0 has point symmetry SL(3,R) was a surprise to physicists. Google ScholarScitation - 7. G. E. Prince and C. J. Eliezer, J. Phys. A 14, 587 (1981). , Google Scholar
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- © 1994 American Institute of Physics.
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