Reconstruction of the primordial fluctuation spectrum from the five-year WMAP data by the cosmic inversion method with band-power decorrelation analysis

TL;DR

This paper reconstructs the primordial fluctuation spectrum from five-year WMAP data using a cosmic inversion method, applying band-power decorrelation to identify deviations from a simple power-law spectrum.

Contribution

It introduces a cosmic inversion approach combined with covariance analysis to reconstruct the primordial spectrum from CMB data, improving previous methods with band-power decorrelation.

Findings

No significant deviation from power-law spectrum in five-year data

Deviations found in first-year data are not confirmed in five-year data

Reconstruction is accurate near the border of the wavenumber domain

Abstract

The primordial curvature fluctuation spectrum is reconstructed by the cosmic inversion method using the five-year WMAP data of the cosmic microwave background temperature anisotropy. We apply the covariance matrix analysis and decompose the reconstructed spectrum into statistically independent band-powers. The statistically significant deviation from a simple power-law spectrum suggested by the analysis of the first-year data is not found in the five-year data except possibly at one point near the border of the wavenumber domain where accurate reconstruction is possible.