Berlin 2005 – wissenschaftliches Programm
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HK: Physik der Hadronen und Kerne
HK 34: Theorie
HK 34.4: Vortrag
Dienstag, 8. März 2005, 17:15–17:30, TU MA042
Correlations in many-body systems with two-time Green’s functions — •K. Morawetz2,3 und H.S. Köhler1 — 1Physics Department, University of Arizona, Tucson, Arizona 85721 — 2Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany — 3Max-Planck-Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden, Germany
The Kadanoff-Baym (KB) equations are solved numerically for infinite nuclear matter. In particular we calculate correlation energies and correlation times. Approximating the Green’s functions in the KB collision kernel by the free Green’s functions the Levinson equation is obtained. This approximation is valid for weak interactions and/or low densities. It relates to the extended quasi-classical approximation for the spectral function. Comparing the Levinson, Born and KB calculations allows for an estimate of higher order spectral corrections to the correlations. A decrease in binding energy is reported due to spectral correlations and off-shell parts in the reduced density matrix [1]. The possibility to reformulate these correlations in terms of nonlocal shifts is presented [2].
[1] H.S. Köhler, K. Morawetz; Phys. Rev. C 64 (2002) 024613
[2] K. Morawetz, P. Lipavsk’y, V. Spicka; Ann. Phys. 294 (2001) 135