Ústav technické a experimentální fyziky Institute of Experimental and Applied Physics

Reproduction of exact solutions of Lipkin model by nonlinear higher random-phase approximation

NázevTitle
Reproduction of exact solutions of Lipkin model by nonlinear higher random-phase approximationReproduction of exact solutions of Lipkin model by nonlinear higher random-phase approximation
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
J. Terasaki, A. Smetana, F. Šimkovic, M. I. Krivoruchenko
DOIDOI
10.1142/S0218301317500628
Časopis / citaceJournal / citation
International Journal of Modern Physics E. 2017, 26(10), ISSN 0218-3013.
RokYear
2017
JazykLanguage
eng
WoSWoS
000414572300004
ScopusScopus
2-s2.0-85031796384
RIVRIV
RIV/68407700:21670/17:00318754!RIV18-MSM-21670___
ProjektProject
Podzemní laboratoř LSM - česká účast ve výzkumné infrastruktuře evropského významuUnderground laboratory LSM - Czech participation to European-level research infrastructure

AbstraktAbstract

It is shown that the random-phase approximation (RPA) method with its nonlinear higher generalization, which was previously considered as approximation except for a very limited case, reproduces the exact solutions of the Lipkin model. The nonlinear higher RPA is based on an equation nonlinear on eigenvectors and includes many particle-many hole components in the creation operator of the excited states. We demonstrate the exact character of solutions analytically for the particle number N = 2 and, numerically, for N = 8. This finding indicates that the nonlinear higher RPA is equivalent to the exact Schrodinger equation, which opens up new possibilities for realistic calculations in many-body problems.

It is shown that the random-phase approximation (RPA) method with its nonlinear higher generalization, which was previously considered as approximation except for a very limited case, reproduces the exact solutions of the Lipkin model. The nonlinear higher RPA is based on an equation nonlinear on eigenvectors and includes many particle-many hole components in the creation operator of the excited states. We demonstrate the exact character of solutions analytically for the particle number N = 2 and, numerically, for N = 8. This finding indicates that the nonlinear higher RPA is equivalent to the exact Schrodinger equation, which opens up new possibilities for realistic calculations in many-body problems.