Reconstruction of broad features in the primordial spectrum and inflaton potential from Planck

Abstract

With the recently published Cosmic Microwave Background data from Planck we address the optimized binning of the primordial power spectrum. As an important modification to the usual binning of the primordial spectrum, along with the spectral amplitude of the bins, we allow the position of the bins also to vary. This technique enables us to address the location of the possible broad physical features in the primordial spectrum with relatively smaller number of bins compared to the analysis performed earlier. This approach is in fact a reconstruction method looking for broad features in the primordial spectrum and avoiding fitting noise in the data. Performing Markov Chain Monte Carlo analysis we present samples of the allowed primordial spectra with broad features consistent with Planck data. To test how realistic it is to have step-like features in primordial spectrum we revisit an inflationary model, proposed by A. A. Starobinsky which can address the similar features obtained from the binning of the spectrum. Using the publicly available code BINGO, we numerically calculate the local $f_{\mathrm{NL}}$ for this model in equilateral and arbitrary triangular configurations of wavevectors and show that the obtained non-Gaussianity for this model is consistent with Planck results. In this paper we have also considered different spectral tilts at different bins to identify the cosmological scale that the spectral index needs to have a red tilt and it is interesting to report that spectral index cannot be well constrained up to $k\sim 0.01{\mathrm{Mpc}}^{-1}$.

23 pages, 6 figures, references added, matches final version published in JCAP

References in corpus (28)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• Primordial Non-Gaussianities from Inflation Models
• Gauge invariant MSSM inflaton
• Generation and Characterization of Large Non-Gaussianities in Single Field Inflation
• Primordial perturbations and non-Gaussianities in DBI and general multi-field inflation
• Primordial fluctuations and non-Gaussianities in multi-field DBI inflation
• 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
• Searching for Oscillations in the Primordial Power Spectrum: Constraints from Planck (Paper II)
• Oscillations in the inflaton potential?
• Model selection applied to reconstruction of the Primordial Power Spectrum
• 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 ?
• Reconstruction of the primordial power spectrum of curvature perturbations using multiple data sets
• Generalized Slow Roll for Non-Canonical Kinetic Terms
• Searching for Oscillations in the Primordial Power Spectrum: Perturbative Approach (Paper I)
• Updating constraints on inflationary features in the primordial power spectrum with the Planck data
• Inflationary Potential Reconstruction for a WMAP Running Power Spectrum
• Band-power reconstruction of the primordial fluctuation spectrum by the maximum likelihood reconstruction method
• Strong scale dependent bispectrum in the Starobinsky model of inflation
• Reconstruction of the primordial fluctuation spectrum from the five-year WMAP data by the cosmic inversion method with band-power decorrelation analysis
• Changes in the halo formation rates due to features in the primordial spectrum
• The scalar bi-spectrum during preheating in single field inflationary models

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• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Model independent evidence for dark energy evolution from Baryon Acoustic Oscillations
• Features and New Physical Scales in Primordial Observables: Theory and Observation
• Tension between the power spectrum of density perturbations measured on large and small scales
• Exploring Cosmic Origins with CORE: Inflation
• Primordial power spectrum from Planck
• Wiggly Whipped Inflation
• Whipped inflation
• Suppressing the impact of a high tensor-to-scalar ratio on the temperature anisotropies
• The Knotted Sky I: Planck constraints on the primordial power spectrum
• Search for features in the spectrum of primordial perturbations using Planck and other datasets
• Ruling out the power-law form of the scalar primordial spectrum
• Primordial features and Planck polarization
• Constraints on inflation with LSS surveys: features in the primordial power spectrum
• Bounds on non-adiabatic evolution in single-field inflation
• Alleviating the tension at low multipole through Axion Monodromy
• Probing features in inflaton potential and reionization history with future CMB space observations
• Joint Planck and WMAP Assessment of Low CMB Multipoles
• Confronting the concordance model of cosmology with Planck data
• Light Sterile Neutrinos and Inflationary Freedom
• Modeling the large-scale power deficit with smooth and discontinuous primordial spectra
• Primordial Power Spectrum features and $f_{NL}$ constraints
• Consistency of the Planck CMB data and $\Lambda$CDM cosmology
• Sharp inflaton potentials and bi-spectra: Effects of smoothening the discontinuity
• Red, Straight, no bends: primordial power spectrum reconstruction from CMB and large-scale structure
• New model of axion monodromy inflation and its cosmological implications
• Power Spectrum and Non-Gaussianities in Anisotropic Inflation
• Effect of damped oscillations in the inflationary potential
• Band-limited Features in the Primordial Power Spectrum Do Not Resolve the Hubble Tension
• Reconstructing the EFT of Inflation from Cosmological Data
• Scale invariance of the primordial tensor power spectrum
• Shapes and features of the primordial bispectrum
• Suppression of scalar power on large scales and associated bispectra
• Spectral Distortion Signatures of Step-like Inflationary Potential
• Unique contributions to the scalar bispectrum in `just enough inflation'
• Inflation Story: slow-roll and beyond
• Revisiting the oscillations in the CMB angular power spectra at $\ell \sim 120$ in the Planck2015 data
• Cross-tests of CMB features in the primordial spectra