We apply the time-dependent variational principle, the nuclear field theory, and the boson expansion method to the Lipkin model to discuss anharmonicities of collective vibrational excitations. It is shown that all of these approaches lead to the same anharmonicity to leading order in the number of particles. Comparison with the exact solution of the Lipkin model shows that these theories reproduce quite well.
- Boson expansion method
- Giant resonance
- Lipkin model
- Nuclear field theory
- Time-dependent variational approach
ASJC Scopus subject areas
- Nuclear and High Energy Physics