On the Momentum Distribution and Condensate Fraction in the Bose Liquid

TL;DR

This paper develops and applies a new set of equations to estimate the momentum distribution and condensate fraction in interacting boson systems at zero temperature, effective in both weak and strong coupling regimes.

Contribution

It introduces linear integro-differential equations based on a recent model to analyze boson systems, extending applicability beyond weak coupling.

Findings

Effective estimates for momentum distribution and condensate fraction.

Analytical solutions provided for weak coupling case.

Applicable to a broad range of interaction strengths.

Abstract

The model recently proposed by A.A. Shanenko [Phys. Lett. A 227 (1997) 367] is used to derive linear integro-differential equations whose solutions provide reasonable estimates for the momentum distribution and condensate fraction in interacting many-boson system at zero temperature. An advantage of these equations is that they can be employed in the weak coupling regime and beyond. As an example, analytical treatment of the weak coupling case is given.