Primordial power spectrum: a complete analysis with the WMAP nine-year data

Abstract

We have improved further the error sensitive Richardson-Lucy deconvolution algorithm making it applicable directly on the un-binned measured angular power spectrum of Cosmic Microwave Background observations to reconstruct the form of the primordial power spectrum. This improvement makes the application of the method significantly more straight forward by removing some intermediate stages of analysis allowing a reconstruction of the primordial spectrum with higher efficiency and precision and with lower computational expenses. Applying the modified algorithm we fit the WMAP 9 year data using the optimized reconstructed form of the primordial spectrum with more than 300 improvement in χ^2 with respect to the best fit power-law. This is clearly beyond the reach of other alternative approaches and reflects the efficiency of the proposed method in the reconstruction process and allow us to look for any possible feature in the primordial spectrum projected in the CMB data. Though the proposed method allow us to look at various possibilities for the form of the primordial spectrum, all having good fit to the data, proper error-analysis is needed to test for consistency of theoretical models since, along with possible physical artefacts, most of the features in the reconstructed spectrum might be arising from fitting noises in the CMB data. Reconstructed error-band for the form of the primordial spectrum using many realizations of the data, all bootstrapped and based on WMAP 9 year data, shows proper consistency of power-law form of the primordial spectrum with the WMAP 9 data at all wave numbers. Including WMAP polarization data in to the analysis have not improved much our results due to its low quality but we expect Planck data will allow us to make a full analysis on CMB observations on both temperature and polarization separately and in combination.

19 pages, 5 figures, discussions extended, results unchanged, matches the final version published in JCAP. Note: JCAP published version contains minor typesetting errors (introduced by JCAP at the proof stage) in the plot labels

References in corpus (17)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Gauge invariant MSSM inflaton
• Inflation and WMAP three year data: Features have a Future!
• CMB polarization features from inflation versus reionization
• New Universal Local Feature in the Inflationary Perturbation Spectrum
• New Constraints on Oscillations in the Primordial Spectrum of Inflationary Perturbations
• Oscillations in the inflaton potential?
• Estimation of Primordial Spectrum with post-WMAP 3 year data
• Features in the Primordial Spectrum from WMAP: A Wavelet Analysis
• Reconstruction of the Primordial Power Spectrum using Temperature and Polarisation Data from Multiple Experiments
• Is a step in the primordial spectral index favored by CMB data ?
• Generalized Slow Roll for Non-Canonical Kinetic Terms
• Inflationary Potential Reconstruction for a WMAP Running Power Spectrum
• Band-power reconstruction of the primordial fluctuation spectrum by the maximum likelihood reconstruction method
• Reconstruction of the primordial fluctuation spectrum from the five-year WMAP data by the cosmic inversion method with band-power decorrelation analysis
• Cosmological parameter estimation with free-form primordial power spectrum
• Changes in the halo formation rates due to features in the primordial spectrum

Cited by in corpus (34)

• Primordial power spectrum from Planck
• Wiggly Whipped Inflation
• Whipped inflation
• The Future of Primordial Features with Large-Scale Structure Surveys
• The Future of Primordial Features with 21 cm Tomography
• Reconstruction of the primordial power spectrum of curvature perturbations using multiple data sets
• Searching for Oscillations in the Primordial Power Spectrum: Perturbative Approach (Paper I)
• On the scalar consistency relation away from slow roll
• The Knotted Sky I: Planck constraints on the primordial power spectrum
• One spectrum to cure them all: Signature from early Universe solves major anomalies and tensions in cosmology
• Generating primordial features at large scales in two field models of inflation
• Reconstruction of broad features in the primordial spectrum and inflaton potential from Planck
• Ruling out the power-law form of the scalar primordial spectrum
• Primordial features and Planck polarization
• Cosmological parameter estimation with free-form primordial power spectrum
• Constraints on holographic multi-field inflation and models based on the Hamilton-Jacobi formalism
• Inflation Wars: A New Hope
• An optimal estimator for resonance bispectra in the CMB
• Parameter discordance in Planck CMB and low-redshift measurements: projection in the primordial power spectrum
• Examining the consistency relations describing the three-point functions involving tensors
• Probing features in inflaton potential and reionization history with future CMB space observations
• Bayesian reconstruction of the inflaton's speed of sound using CMB data
• Numerical evaluation of the three-point scalar-tensor cross-correlations and the tensor bi-spectrum
• Axions as Hot and Cold Dark Matter
• Constraints on features in the inflationary potential from future Euclid data
• Sharp inflaton potentials and bi-spectra: Effects of smoothening the discontinuity
• PRISM: Sparse Recovery of the Primordial Power Spectrum
• Test of consistency between Planck and WMAP
• High-resolution CMB bispectrum estimator with flexible modal basis
• Searching for local features in primordial power spectrum using genetic algorithms
• Constraining stochastic gravitational wave background from weak lensing of CMB B-modes
• The scalar-scalar-tensor inflationary three-point function in the axion monodromy model
• Inflation Story: slow-roll and beyond
• Probing inflation with large-scale structure data: the contribution of information at small scales