Summary
We consider the problem of finding, for a given quantum system, a compact Lie group of symmetries such that to any energy level there corresponds an irreducible representation of the group. It is concluded that this is not possible except for particular cases, and that, in general, to a given energy level there corresponds a reducible representation of the group. Examples with such a behaviour are given.
Riassunto
Si considera il problema di trovare, per un sistema quantistico dato, un compatto gruppo di Lie di simmetrie, tale che ad ogni livello di energia corrisponda una rappresentazione irriducibile del gruppo. Si conclude che ciò non è possibile salvo che in particolari casi, e che, in generale, ad un livello di energia data corrisponde una rappresentazione riducibile del gruppo. Si danno esempi di tale fenomeno.
Реэюме
Мы рассматриваем проблему нахождения для данной квантовой системы компактной группы Ли таких симметрий, что любому уровню знергии соответствует неприводимое представление зтой группы. Утверждается, что зто невоэможно, эа исключением частных случаев, и что, в обшем случае, эаданному уровню знергии соответствует неприводимое представление группы. Приводятся примеры с таким поведением.
Similar content being viewed by others
References
G. Maiella andG. Vilasi:Lett. Nuovo Cimento,1, 57 (1969).
V. A. Fock:Zeits. Phys.,98, 145 (1935); for recent publications see, for instance,H. Bacry, H. Ruegg andJ. M. Souriau:Comm. Math. Phys.,3, 323 (1966);A. Simoni, B. Vitale andF. Zaccaria:Nuovo Cimento,50 A, 95 (1967).
E. L. Hill andJ. M. Jauch:Phys. Rev.,57, 6411 (1940); for recent publications see, for instance:Yu. N. Demkov:Vestnik Leningrad State University,11, 127 (1953) (Sov. Phys. JETP,26, 757 (1954));G. A. Baker jr.:Phys. Rev.,103, 1119 (1956).
L. D. Landau andE. Lifchitz:Mécanique (Moscow, 1966).
This result is independent of the hypothesisa).
The one-dimensional system (14) has been investigated from the point of view of the noninvariance group byH. Bacry andJ. L. Richard:Journ. Math. Phys.,8, 2230 (1967).
Author information
Authors and Affiliations
Additional information
Stay supported by Fondazione «A. Beneduce», Napoli.
Rights and permissions
About this article
Cite this article
De Angelis, G.F., Vilasi, G. A note on quantum-dynamical symmetries. Nuov Cim A 6, 38–48 (1971). https://doi.org/10.1007/BF02723432
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02723432