Effects of local features of the inflaton potential on the spectrum and bispectrum of primordial perturbations

Abstract

We study the effects of a class of features of the potential of slow-roll inflationary models corresponding to a step symmetrically dumped by an even power negative exponential factor, which we call local features. Local-type features differ from other branch-type features considered previously, because the potential is only affected in a limited range of the scalar field value, and are symmetric respect to the location of the feature. This type of features only affects the spectrum and bispectrum in a narrow range of scales which leave the horizon during the time interval corresponding to the modification of the potential. On the contrary branch-type features have effects on all the perturbation modes leaving the horizon when the field value is within the interval defining the branch, introducing for example differences in the power spectrum between large and small scale which are absent in the case of local-type features. The spectrum and bispectrum of primordial curvature perturbations are affected by oscillations around the scale $k_0$ exiting the horizon at the time ${\tau }_0$ corresponding to the feature. We also compute the effects of the features on the CMB temperature and polarization spectra, showing the effects or different choices of parameters.

23 pages, 18 figures, new section added with examples of how the effects of branch features differ those of local features

References in corpus (18)

• Primordial Non-Gaussianities from Inflation Models
• 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
• Measurements of Sub-degree B-mode Polarization in the Cosmic Microwave Background from 100 Square Degrees of SPTpol Data
• BICEP2 / Keck Array V: Measurements of B-mode Polarization at Degree Angular Scales and 150 GHz by the Keck Array
• Effects of particle production during inflation
• Primordial power spectrum from Planck
• Wiggly Whipped Inflation
• Whipped inflation
• 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 ?
• Untangling features in the primordial spectra
• Reconstruction of the primordial fluctuation spectrum from the five-year WMAP data by the cosmic inversion method with band-power decorrelation analysis
• Light Sterile Neutrinos and Inflationary Freedom
• Primordial Non-Gaussianities of inflationary step-like models
• Primordial non-Gaussianities produced by features in the potential of single slow-roll inflationary models
• Robustness of cosmological axion mass limits

Cited by in corpus (14)

• Precise measurements of inflationary features with 21 cm observations
• Features of the inflaton potential and the power spectrum of cosmological perturbations
• Spectrum oscillations from features in the potential of single-field inflation
• Constraints on inflation with LSS surveys: features in the primordial power spectrum
• Bayesian analysis of inflationary features in Planck and SDSS data
• Primordial power spectrum features in phenomenological descriptions of inflation
• Features in single field slow-roll inflation
• Scale invariance of the primordial tensor power spectrum
• Impact of cosmological signatures in two-point statistics beyond the linear regime
• Degeneracy in the spectrum and bispectrum among featured inflaton potentials
• One spectrum to rule them all?
• The running of featureful primordial power spectra
• Investigating the Constraints on Primordial Features with Future Cosmic Microwave Background and Galaxy Surveys
• Cross-tests of CMB features in the primordial spectra