Eur. Phys. J. A (2004) 19: 215-220
https://doi.org/10.1140/epja/i2003-10145-8

Eigenstates of the time-dependent density-matrix theory

¹ Kyorin University School of Medicine, 181-8611, Mitaka, Tokyo, Japan
² Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, F-91406, Orsay Cedex, France

^* e-mail: tohyama@kyorin-u.ac.jp

Abstract

An extended time-dependent Hartree-Fock theory, known as the time-dependent density-matrix theory (TDDM), is solved as a time-independent eigenvalue problem for low-lying 2 ⁺ states in ²⁴O to understand the foundation of the rather successful time-dependent approach. It is found that the calculated strength distribution of the 2 ⁺ states has physically reasonable behavior and that the strength function is practically positive definite though the non-Hermitian Hamiltonian matrix obtained from TDDM does not guarantee it. A relation to an Extended RPA theory with hermiticity is also investigated. It is found that the density-matrix formalism is a good approximation to the Hermitian Extended RPA theory.