论文标题
一种简化的方法，可用于从低密度到高密度的排斥性玻色气体及其数值准确性
A simplified approach to the repulsive Bose gas from low to high densities and its numerical accuracy
论文作者
论文摘要
1963年，开发了一种简单的方法来研究相互作用的玻色气体的基态能量。它在于方程式的推导，该方程不是基于扰动理论，它给出了低密度下能量的精确扩展。该方程直接在热力学限制中表示，仅涉及$ 3 $变量的功能，而不是$ 3N $。在这里，我们重新审视这种方法，并表明方程对所有密度的各种可观察物都产生了准确的预测。具体而言，除了基态能量外，我们还表明，简单的方法可以预测冷凝物分数，两点相关函数和动量分布。我们通过将方程的预测与量子蒙特卡洛计算进行比较，进行了多种测试，并发现了显着的一致性。因此，我们表明，简单的方法提供了一种新的理论工具来理解多体bose气体的行为，不仅在以前已经研究过的小密度和大密度范围内，而且在中间密度的范围内，对此几乎没有知道。
In 1963, a Simple Approach was developed to study the ground state energy of an interacting Bose gas. It consists in the derivation of an Equation, which is not based on perturbation theory, and which gives the exact expansion of the energy at low densities. This Equation is expressed directly in the thermodynamic limit, and only involves functions of $3$ variables, rather than $3N$. Here, we revisit this approach, and show that the Equation yields accurate predictions for various observables for all densities. Specifically, in addition to the ground state energy, we have shown that the Simple Approach gives predictions for the condensate fraction, two-point correlation function, and momentum distribution. We have carried out a variety of tests by comparing the predictions of the Equation with Quantum Monte Carlo calculations, and have found remarkable agreement. We thus show that the Simple Approach provides a new theoretical tool to understand the behavior of the many-body Bose gas, not only in the small and large density ranges, which have been studied before, but also in the range of intermediate density, for which little is known.
