Year: 2005
Type: article
Abstract: The power spectrum is traditionally parametrized by a truncated Taylor series: . It is reasonable to truncate the Taylor series if , but it is not if . We argue that there is no good theoretical reason to prefer , and show that current observations are consistent with | n * 'ln( k / k * )| ∼ | n * − 1| even for |ln( k / k * )| ∼ 1. Thus, there are regions of parameter space, which are both theoretically and observationally relevant, for which the traditional truncated Taylor series parametrization is inconsistent, and hence it can lead to incorrect parameter estimations. Motivated by this, we propose a simple extension of the traditional parametrization, which uses no extra parameters, but that, unlike the traditional approach, covers well motivated inflationary spectra with | n * '| ∼ | n * − 1|. Our parametrization therefore covers not only standard slow-roll inflation models but also a much wider class of inflation models. We use this parametrization to perform a likelihood analysis for the cosmological parameters.
Authors: Kevork Abazajian, Kenji Kadota, Ewan D Stewart
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1987952837