Lensing anomaly and oscillations in the primordial power spectrum

Abstract

The latest analysis of the cosmic microwave background by the Planck team finds more smoothing of the acoustic peaks in the temperature power spectrum than predicted by $\Lambda$CDM. Here we investigate whether this additional smoothing can be mimicked by an oscillatory feature, generated during inflation, that is similar to the acoustic peaks but out of phase. We consider oscillations generated by oscillating modulations of the background -- e.g., due to heavy fields or modulated potentials -- and by sharp features. We show that it is difficult to induce oscillations that are linear (or almost linear) in $k$ by oscillatory modulations of the background. We find, however, that a sharp bumpy feature in the sound speed of perturbations is able to produce the desired oscillations. The scenario can be tested by combining CMB and BAO data.

revised version, new plot added. v3: minor typo found when comparing eq. (3.21) with residuals. Now it is found B<0 and c_s<1. Conclusions unchanged

References in corpus (21)

• The Effective Field Theory of Inflation
• Causality, Analyticity and an IR Obstruction to UV Completion
• Monodromy in the CMB: Gravity Waves and String Inflation
• The Cosmic Linear Anisotropy Solving System (CLASS) I: Overview
• Cosmic Microwave Weak lensing data as a test for the dark universe
• Mass hierarchies and non-decoupling in multi-scalar field dynamics
• Non-gaussianity from the trispectrum in general single field inflation
• Oscillations in the inflaton potential?
• Primordial power spectrum from Planck
• Models of the Primordial Standard Clock
• Standard Clock in Primordial Density Perturbations and Cosmic Microwave Background
• Wiggly Whipped Inflation
• Generalized Slow Roll for Non-Canonical Kinetic Terms
• Unique Fingerprints of Alternatives to Inflation in the Primordial Power Spectrum
• Untangling features in the primordial spectra
• The effect of varying sound velocity on primordial curvature perturbations
• Parameter discordance in Planck CMB and low-redshift measurements: projection in the primordial power spectrum
• Searching for Oscillations in the Primordial Power Spectrum with CMB and LSS Data
• Optimal analysis of the CMB trispectrum
• Mimicking alternatives to inflation with interacting spectator fields
• Reconstructing the EFT of Inflation from Cosmological Data

Cited by in corpus (17)

• The galaxy power spectrum take on spatial curvature and cosmic concordance
• Cosmological constraints in extended parameter space from the Planck 2018 Legacy release
• One spectrum to cure them all: Signature from early Universe solves major anomalies and tensions in cosmology
• Planck residuals anomaly as a fingerprint of alternative scenarios to inflation
• Comparing multi-field primordial feature models with the Planck data
• Euclid: The search for primordial features
• A thorough investigation of the prospects of eLISA in addressing the Hubble tension: Fisher Forecast, MCMC and Machine Learning
• Dark acoustic oscillations: Imprints on the matter power spectrum and the halo mass function
• Band-limited Features in the Primordial Power Spectrum Do Not Resolve the Hubble Tension
• On the primordial origin of the smoothing excess in the $Planck$ temperature power spectrum in light of LSS data
• Optimising Inflationary Features the Bayesian Way
• Understanding large scale CMB anomalies with the generalized non-minimal derivative coupling during inflation
• The Atacama Cosmology Telescope: Delensed Power Spectra and Parameters
• Exploring Early and Late Cosmology with Next Generation Surveys
• Knot reconstruction of the scalar primordial power spectrum with Planck, ACT, and SPT CMB data
• Do JWST reionization (optical depth) puzzle, cosmological tensions, and CMB anomalies imply Harrison-Zel'dovich spectrum?
• Investigating the Constraints on Primordial Features with Future Cosmic Microwave Background and Galaxy Surveys