title: Field theory of bicritical and tetracritical points. III. Relaxational dynamics including conservation of magnetization (model C).
abstract: We calculate the relaxational dynamical critical behavior of systems of O(n_{ parallel}) plus sign in circleO(n_{ perpendicular}) symmetry including conservation of magnetization by renormalization group theory within the minimal subtraction scheme in two-loop order. Within the stability region of the Heisenberg fixed point and the biconical fixed point, strong dynamical scaling holds, with the asymptotic dynamical critical exponent z=2varphinu-1 , where varphi is the crossover exponent and nu the exponent of the correlation length. The critical dynamics at n_{ parallel}=1 and n_{ perpendicular}=2 is governed by a small dynamical transient exponent leading to nonuniversal nonasymptotic dynamical behavior. This may be seen, e.g., in the temperature dependence of the magnetic transport coefficients.
authors.affiliation: Institute for Theoretical Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040, Linz, Austria. folk@tphys.uni-linz.ac.at
authors.forename: R
authors.initials: R
authors.lastname: Folk
authors.forename: Yu
authors.initials: Y
authors.lastname: Holovatch
authors.forename: G
authors.initials: G
authors.lastname: Moser