Dresden 2011 – scientific programme

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A: Fachverband Atomphysik

A 16: Atomic systems in external fields I

A 16.6: Talk

Wednesday, March 16, 2011, 15:15–15:30, BAR 106

Global fixed point proof for time-dependent density functional theory — •Michael Ruggenthaler and Robert van Leeuwen — Department of Physics, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland

Time-dependent density-functional theory is the extension of the highly successful ground-state density-functional theory to time-dependent phenomena. The basic theorem by Runge and Gross [1] shows under the assumption of Taylor-expandable external potentials that every observable is in principle uniquely defined by the one-particle density of the quantum system. The van Leeuwen theorem [2] provides under similar restrictions, that there is an auxiliary system of noninteracting particles generating the exact density of the interacting system. This so-called Kohn-Sham construction makes an ab initio solution for big quantum systems feasible. By rewriting the question whether a system is uniquely defined by its density as a fixed point question, we can proof both theorems without assumptions on the time-dependence of the potentials. We discuss implications and applications of this novel approach to fundamental questions of many-body physics.

[1] E. Runge and E.K.U. Gross, Phys. Rev. Lett. 52, 997 (1984).

[2] R. van Leeuwen, Phys. Rev. Lett. 82, 3863 (1999).