TY - JOUR
T1 - On Adiabatic Renormalization of Inflationary Perturbations
AU - Durrer, Ruth
AU - Marozzi, Giovanni
AU - Rinaldi, Massimiliano
N1 - 7 pages, 3 figures, revtex. New version with more results and modified plots
PY - 2009/6/25
Y1 - 2009/6/25
N2 - We discuss the impact of adiabatic renormalization on the power spectrum of scalar and tensor perturbations from inflation. We show that adiabatic regularization is ambiguous as it leads to very different results, for different adiabatic subtraction schemes, both in the range $v\equiv k/(aH) \gsim 0.1$ and in the infrared regime. All these schemes agree in the far ultraviolet, $v\gg 1$. Therefore, we argue that in the far infrared regime, $v\ll 1$, the adiabatic expansion is no longer valid, and the unrenormalized spectra are the physical, measurable quantities. These findings cast some doubt on the validity of the adiabatic subtraction at horizon exit, $v=1$, to determine the perturbation spectra from inflation which has recently advocated in the literature.
AB - We discuss the impact of adiabatic renormalization on the power spectrum of scalar and tensor perturbations from inflation. We show that adiabatic regularization is ambiguous as it leads to very different results, for different adiabatic subtraction schemes, both in the range $v\equiv k/(aH) \gsim 0.1$ and in the infrared regime. All these schemes agree in the far ultraviolet, $v\gg 1$. Therefore, we argue that in the far infrared regime, $v\ll 1$, the adiabatic expansion is no longer valid, and the unrenormalized spectra are the physical, measurable quantities. These findings cast some doubt on the validity of the adiabatic subtraction at horizon exit, $v=1$, to determine the perturbation spectra from inflation which has recently advocated in the literature.
U2 - 10.1103/PhysRevD.80.065024
DO - 10.1103/PhysRevD.80.065024
M3 - Article
SN - 1550-7998
JO - Phys.Rev.D
JF - Phys.Rev.D
ER -