Renormalization group inspired autonomous equations for secular effects in de Sitter space
Abstract
We develop a method for treating a series of secularly growing terms obtained from quantum perturbative calculations: autonomous firstorder differential equations are constructed such that they reproduce this series to the given order. The exact solutions of these equations are free of secular terms and approach a finite limit at late times. This technique is illustrated for the wellknown problem of secular growth of correlation functions of a massless scalar field with a quartic selfinteraction in de Sitter space. For the expectation value of the product of two fields at coinciding spacetime points, we obtain a finite latetime result that is very close to the one following from Starobinsky's stochastic approach.
 Publication:

Physical Review D
 Pub Date:
 September 2020
 DOI:
 10.1103/PhysRevD.102.065010
 arXiv:
 arXiv:2005.02504
 Bibcode:
 2020PhRvD.102f5010K
 Keywords:

 High Energy Physics  Theory;
 General Relativity and Quantum Cosmology
 EPrint:
 20 pages