Regensburg 2004 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 10: Critical Phenomena

DY 10.5: Vortrag

Montag, 8. März 2004, 10:45–11:00, H2

Exact renormalization group analysis of the O(2) theory including all marginal and relevant coupling parameters — •Nils Hasselmann, Sascha Ledowski, and Peter Kopietz — Institut für Theoretische Physik, Universität Frankfurt, Robert-Mayer-Str. 8, 60054 Frankfurt/Main

We use the exact renormalization group formalism to study the critical regime of the O(2) theory in dimensions 4>D≥ 3 analytically. Besides the two relevant parameters, the mass parameter and the constant part of the 4-point vertex, our analysis tracks also the flow of all three marginal parameters at D=3. Two marginal parameters characterize the lowest order momentum dependence of the 4-point vertex and the third is the momentum-independent part of the 6-point vertex. We find competitive results for the critical exponents ν and η.