2020/06/16 by M. Tohyama, Tohyama, Mitsuru
Physics and Astronomy · #Quantum, superfluid, helium dynamics #Advanced Chemical Physics Studies #Cold Atom Physics and Bose-Einstein Condensates
paper · pdf · doi:10.48550/arxiv.2006.09561
Perturbative approaches have often been used to include the effects of ground-state correlations in extended theories of the random-phase approximation. Validity of such approaches is investigated for a solvable model where comparison with exact solutions can be made. It is pointed out that there is a case where perturbative approaches give good results in spite of the fact that interaction strength is far beyond a perturbative region.