Introduction to the nonequilibrium functional renormalization group

Inflation and nonequilibrium renormalization group

We study de spectrum of primordial fluctuations and the scale dependence of the inflaton spectral index due to self-interactions of the field. We compute the spectrum of fluctuations by applying nonequilibrium renormalization group techniques. PACS numbers: 98.80.Cq, 11.10.Hi, 11.10.Jj Submitted to: J. Phys. A: Math. Gen. In this paper we explore a mechanism to explain departures of the primord...

An Introduction to the Nonperturbative Renormalization Group

An elementary introduction to the non-perturbative renormalization group is presented mainly in the context of statistical mechanics. No prior knowledge of field theory is necessary. The aim is this article is not to give an extensive overview of the subject but rather to insist on conceptual aspects and to explain in detail the main technical steps. It should be taken as an introduction to mor...

Disordered Systems and the Functional Renormalization Group, a Pedagogical Introduction

In this article, we review basic facts about disordered systems, especially the existence of many metastable states and and the resulting failure of dimensional reduction. Besides techniques based on the Gaussian variational method and replica-symmetry breaking (RSB), the functional renormalization group (FRG) is the only general method capable of attacking strongly disordered systems. We expla...

An introduction to real-time renormalization group

A nonequilibrium renormalization group approach to turbulent reheating

We use nonequilibrium renormalization group (RG) techniques to analyze the thermalization process in quantum field theory, and by extension reheating after inflation. Even if at a high scale Λ the theory is described by a non-dissipative λφ theory, the RG running induces nontrivial noise and dissipation. For long wavelength, slowly varying field configurations, the noise and dissipation are whi...