A Comment on the Path Integral Approach to Cosmological Perturbation Theory
arXiv:0711.0867 · doi:10.1088/1475-7516/2008/01/029
Abstract
It is pointed out that the exact renormalization group approach to cosmological perturbation theory, proposed in Matarrese and Pietroni, JCAP 0706 (2007) 026, arXiv:astro-ph/0703563 and arXiv:astro-ph/0702653, constitutes a misnomer. Rather, having instructively cast this classical problem into path integral form, the evolution equation then derived comes about as a special case of considering how the generating functional responds to variations of the primordial power spectrum.
2 pages, v2: refs added, published in JCAP