Perturbed Power-law parameters from WMAP7

TL;DR

This paper introduces a perturbative method to analyze inflation models with slight deviations from scale invariance, providing a new way to interpret WMAP-7 data.

Contribution

It develops a perturbative approach for inflation spectra that captures spectral index running, differing from traditional slow roll methods.

Findings

PPL parameters are well constrained by WMAP-7 data

The method effectively models deviations from scale invariance

Provides a new framework for analyzing inflation spectra

Abstract

We present a perturbative approach for studying inflation models with soft departures from scale free spectra of the power law model. In the perturbed power law (PPL) approach one obtains at the leading order both the scalar and tensor power spectra with the running of their spectral indices, in contrast to the widely used slow roll expansion. The PPL spectrum is confronted data and we show that the PPL parameters are well estimated from WMAP-7 data.