Truncation scheme of time-dependent density-matrix approach II

TL;DR

This paper improves a truncation scheme for the hierarchy of reduced density matrices in time-dependent density-matrix approaches, enhancing accuracy by considering normalization effects, and validates it using the Lipkin model.

Contribution

The paper introduces an improved truncation scheme that accounts for normalization effects in the hierarchy of density matrices, enhancing the accuracy of time-dependent density-matrix methods.

Findings

Results agree well with exact solutions in the Lipkin model

Normalization effects improve the accuracy of the truncation scheme

Method provides a better approximation for three-body density matrices

Abstract

A truncation scheme of the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy for reduced density matrices, where a three-body density matrix is approximated by two-body density matrices, is improved to take into account a normalization effect. The truncation scheme is tested for the Lipkin model. It is shown that the obtained results are in good agreement with the exact solutions.