Dilute Bose gas: short-range particle correlations and ultraviolet divergence

Abstract

The modified Bogoliubov model where the primordial interaction is replaced by the t matrix is reinvestigated. It is shown to provide a negative value of the kinetic energy for a strongly interacting dilute Bose gas, contrary to the original Bogoliubov model. To clear up the origin of this failure, the correct values of the kinetic and interaction energies of a dilute Bose gas are calculated. It is demonstrated that both the problem of the negative kinetic energy and the ultraviolet divergence, dating back to the well-known paper of Lee, Yang and Huang, is connected with an inadequate picture of the short-range boson correlations. These correlations are reconsidered within the thermodynamically consistent model proposed earlier by the present authors. Found results are in absolute agreement with the data of the Monte-Carlo calculations for the hard-sphere Bose gas.

11 pages, REVTeX, 2 figures inserted

Cited by in corpus (10)

• Dilute Bose gas in two dimensions: Density expansions and the Gross-Pitaevskii equation
• The kinetic and interaction energies of a trapped Bose gas: Beyond the mean field
• Self-consistent calculation of the coupling constant in the Gross-Pitaevskii equation
• Low-density expansions for the homogeneous dipolar Bose gas at zero temperature
• Tan's adiabatic sweep theorem from the variational theorem for the scattering length
• Condensate fluctuations in the dilute Bose gas
• The variational theorem for the scattering length in low dimensions and its applications to universal systems
• Adiabatic sweep theorem for three-dimensional dipolar Bose gases
• Dilute Fermi gas: kinetic and interaction energies
• Confinement-induced resonance from the generalized Gross-Pitaevskii equations