Eur. Phys. J. A 16, 35-42 (2003)
DOI: 10.1140/epja/i2002-10075-y

A consistent approximation scheme beyond RPA for bosons

D. Davesne, M. Oertel and H. Hansen

IPN Lyon, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne Cedex, France

davesne@ipnl.in2p3.fr

(Received: 17 June 2002 / Revised version: 23 August 2002 / Published online: 17 January 2003)

Abstract
In this paper, we develop a consistent extension of RPA for bosonic systems. In order to illustrate the method, we consider the case of the anharmonic oscillator. We compare our results with those obtained in mean-field and standard RPA approaches with the exact ones and show that they are very close to these ones.

PACS
24.10.Cn - Many-body theory.
04.25.-g - Approximation methods; equations of motion.

© Società Italiana di Fisica, Springer-Verlag 2003