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Renormalization group and nonequilibrium action in stochastic field theory

Juan Zanella·Esteban Calzetta
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Abstract

We investigate the renormalization group approach to nonequilibrium field theory. We show that it is possible to derive nontrivial renormalization group flow from iterative coarse graining of a closed-time-path action. This renormalization group is different from the usual in quantum field theory textbooks, in that it describes nontrivial noise and dissipation. We work out a specific example where the variation of the closed-time-path action leads to the so-called Kardar-Parisi-Zhang equation, and show that the renormalization group obtained by coarse graining this action, agrees with the dynamical renormalization group derived by directly coarse graining the equations of motion.

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Juan Zanella, Esteban Calzetta. 2002-04-02. Renormalization group and nonequilibrium action in stochastic field theory. https://doi.org/10.1103/physreve.66.036134

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