The gauge-invariant periodic quantization method is applied to time-dependent states with definite parities in the Lipkin-Meshkov-Glick model. It is shown that the resulting discrete energy spectrum is free of discontinuity and predicts the correct number of states for all interaction strengths. It offers therefore a qualitative improvement over the gauge-invariant periodic quantized time-dependent Hartree-Fock states of this model.

NUCLEAR STRUCTURE Time-dependent description of many-body bound states, gauge-invariant periodic quantization method, Lipkin-Meshkov-Glick model, good-parity time-dependent states.

• Received 25 March 1980

DOI:https://doi.org/10.1103/PhysRevC.22.2228