Constraints on tensor to scalar ratio using WKB approximation

2018/09/30 by Aiswarya. A, A. Aiswarya, Minu Joy
Physics and Astronomy · #Advanced Mathematical Theories and Applications #CMB cold spot #Cosmology and Gravitation Theories #Inflation (cosmology) #Invariant (physics) #Noncommutative and Quantum Gravity Theories #Scalar (mathematics) #Scale invariance #Spectral line #Tensor (intrinsic definition) #WKB approximation #astro-ph.CO

paper · pdf · doi:10.1088/1475-7516/2019/02/025

published as JCAP02(2019)025 · 13 pages, 4 figures

openalex created_date 2018/09/27 · openalex publication_date 2019/02/13 · arxiv created 2019/02/18 · arxiv updated 2019/02/19 · openalex updated_date 2026/08/06

Abstract

Using Wenzel-Kramers-Brillouin (WKB) approximation the scalar and tensor power spectra are obtained. Scale invariant spectra are obtained and the spectral indices come very close to the observed data from WMAP and Planck experiments. The advantage of this method is that, it is valid even when slow-roll approximation fails. Constraints on the tensor to scalar ratio( r ) is also studied with the WKB Approximation. We use the Power law inflation as the base model as it allows comparison with exact results.

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