Author(s):

Seiringer, Robert

Article Title: 
A correlation estimate for quantum manybody systems at positive temperature

Affiliation 

Abstract: 
We present an inequality that gives a lower bound on the expectation value of certain twobody interaction potentials in a general state on Fock space in terms of the corresponding expectation value for thermal equilibrium states of noninteracting systems and the difference in the free energy. This bound can be viewed as a rigorous version of firstorder perturbation theory for manybody systems at positive temperature. As an application, we give a proof of the first two terms in a high density (and high temperature) expansion of the free energy of jellium with Coulomb interactions, both in the fermionic and bosonic case. For bosons, our method works above the transition temperature (for the noninteracting gas) for BoseEinstein condensation.

Keywords: 
BoseEinstein condensation; Thermodynamic limit; Correlation inequality; Jellium; Quantum manybody system; Quasifree states

Journal Title:

Reviews in Mathematical Physics

Volume: 
18

Issue 
3

ISSN:

0129055X

Publisher:

World Scientific Publishing

Date Published:

20060401

Start Page: 
233

End Page:

253

URL: 

DOI: 
10.1142/S0129055X06002632

Open access: 
yes (repository) 