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Renormalization group and nonequilibrium action in stochastic field theory
Juan Zanella1, Esteban Calzetta
1Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires-Ciudad Universitaria, Pabellon I, Argentina. zanellaj@dfuba.df.uba.ar
Summary
We present a novel renormalization group approach for nonequilibrium field theory, revealing nontrivial noise and dissipation. This method aligns with dynamical renormalization groups, offering new insights into complex systems.
Area of Science:
- * Theoretical physics
- * Statistical mechanics
- * Condensed matter physics
Background:
- * Traditional renormalization group (RG) methods are primarily used for equilibrium systems in quantum field theory.
- * Nonequilibrium systems present unique challenges due to inherent time-dependence, noise, and dissipation.
- * Understanding the behavior of systems far from equilibrium is crucial in various scientific domains.
Purpose of the Study:
- * To develop and investigate a renormalization group approach applicable to nonequilibrium field theories.
- * To demonstrate that iterative coarse-graining of a closed-time-path action can yield nontrivial RG flow.
- * To establish the consistency of this novel RG approach with established methods for specific nonequilibrium models.
Main Methods:
- * Employing a closed-time-path (CTP) action formalism to describe nonequilibrium quantum field theory.
- * Applying iterative coarse-graining techniques to the CTP action to derive RG flow equations.
- * Analyzing a specific model, the Kardar-Parisi-Zhang (KPZ) equation, as a test case.
- * Comparing the RG flow derived from the CTP action with that obtained from directly coarse-graining the equations of motion.
Main Results:
- * A new type of renormalization group flow has been derived from the coarse-graining of a CTP action.
- * This RG flow explicitly incorporates nontrivial noise and dissipation, characteristic of nonequilibrium systems.
- * The RG analysis of the KPZ equation using the CTP action yields results consistent with the dynamical RG derived from the equations of motion.
Conclusions:
- * The presented renormalization group approach offers a viable framework for studying nonequilibrium field theories.
- * Coarse-graining the CTP action provides a consistent method to introduce and handle noise and dissipation within RG.
- * This work bridges the gap between equilibrium and nonequilibrium RG formalisms, with implications for diverse physical systems.
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