Ursell operators in statistical physics II: microscopic properties of a dilute quantum gas

P. Grüter, Franck Laloë

Jean-Noël Fuchs, Markus Holzmann, Franck Laloë

W. Ebeling, Thorsten Pöschel

P. Grüter, Franck Laloë

We apply the formalism of Ursell operators, introduced in a previous article, to the calculation of reduced density operators (one and two-body density operators) in a dilute quantum gas; the calculation is not a fugacity expansion and is therefore not limited to low degrees of degeneracy. We obtain quantum corrections for the one-particle density operator as a function of the second Ursell operator. For the two-body density operator, we examine how statistics and interactions combine their effects on the correlations between particles; in particular we discuss in detail how hard cores potentials affect the short range correlations, a non-perturbative effect.

Franck Laloë

Using Ursell operators for the study of the poperties of dilute degenerate gases

V. Pastukhov