On the 'Strong-Coupling' Generalization of the Bogoliubov Model

TL;DR

This paper introduces a generalized Bogoliubov model for Bose gases that accurately accounts for both long-range and short-range correlations, applicable to strong interactions and reducing to the classical model in weak coupling.

Contribution

It presents a novel approach that extends the Bogoliubov model to strong-coupling regimes by incorporating in-medium Schrödinger equations for pair wave functions.

Findings

Provides reasonable results for strongly interacting dilute Bose gases.

Unifies weak and strong coupling regimes within a single framework.

Enhances understanding of Bose gas correlations in various interaction regimes.

Abstract

A generalized Bogoliubov model of the Bose gas in the ground state is proposed which properly takes into account both the long-range and short-range spatial boson correlations. It concerns equilibrium characteristics and operates with in-medium Schrodinger equations for the pair wave functions of bosons being the eigenfunctions of the second-order reduced density matrix. The approach developed provides reasonable results for a dilute Bose gas with arbitrary strong interaction between particles (the 'strong-coupling' case) and comes to the canonical Bogoliubov model in the weak-coupling regime.