On the ground state energy of the inhomogeneous Bose gas

作     者：V. B. Bobrov S. A. Trigger 

作者机构：Joint Institute for High Temperatures Russian Academy of Sciences 13/19 Izhorskaia Str. Moscow 125412 Russia 

出 版 物：《Frontiers of physics》 (物理学前沿（英文版）)

年 卷 期：2017年第12卷第3期

页      面：197-201页

核心收录：

学科分类：07[理学] 08[工学] 081402[工学-结构工程] 081304[工学-建筑技术科学] 0813[工学-建筑学] 070202[理学-粒子物理与原子核物理] 0814[工学-土木工程] 0702[理学-物理学] 

基　　金：supported by the Russian Science Foundation 

主　　题：Bose condensation elementary excitations single-particle Green function density-density Green function thermodynamic energy 

摘      要：Within the self-consistent Hartree^Fock approximation, an explicit in this approximation expression for the ground state energy of inhomogeneous Bose gas is derived as a functional of the inhomogeneous density of the Bose-Einstein condensate. The results obtained are based on existence of the off-diagonal long-range order in the single-particle density matrix for systems with a Bose-Einstein condensate. This makes it possible to avoid the use of anomalous averages. The explicit form of the kinetic energy, which differs from one in the Gross-Pitaevski approach, is found. The obtained form of kinetic energy is valid beyond the Hartree--Fock approximation and can be applied for arbitrary strong interparticle interaction.