Searching for features of a string-inspired inflationary model with cosmological observations

Abstract

The latest Planck results show a power deficit in the temperature anisotropies near $\ell \approx 20$ in the cosmic microwave background (CMB). This observation can hardly be explained within the standard inflationary $\Lambda$-cold-dark-matter ($\Lambda$CDM) scenario. In this paper we consider a string theory inspired inflationary model (axion monodromy inflation) with a step-like modulation in the potential which gives rise to observable signatures in the primordial perturbations. One interesting phenomenon is that the primordial scalar modes experience a sudden suppression at a critical scale when the modulation occurs. By fitting to the CMB data, we find that the model can nicely explain the $\ell \approx 20$ power deficit anomaly as well as predict specific patterns in the temperature-polarization correlation and polarization autocorrelation spectra. Though the significance of the result is not sufficient to claim a detection, our analysis reveals that fundamental physics at extremely high energy scales, namely, some effects inspired by string theory, may be observationally testable in forthcoming cosmological experiments.

6 pages, 4 figures. Replaced to match published version

References in corpus (13)

• Monodromy in the CMB: Gravity Waves and String Inflation
• The Powers of Monodromy
• CMB polarization features from inflation versus reionization
• Energy Transfer in Multi Field Inflation and Cosmological Perturbations
• Models of the Primordial Standard Clock
• Wiggly Whipped Inflation
• Searching for Standard Clocks in the Primordial Universe
• Untangling features in the primordial spectra
• Consistency relations for sharp features in the primordial spectra
• Joint Planck and WMAP Assessment of Low CMB Multipoles
• Effect of transitions in the Planck mass during inflation on primordial power spectra
• Pre-Inflationary Relics in the CMB?
• Primordial Non-Gaussianities of inflationary step-like models

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• Inflationary Features and Shifts in Cosmological Parameters from Planck 2015 Data
• Brane SUSY Breaking and the Gravitino Mass
• Robust predictions for an oscillatory bispectrum in Planck 2015 data from transient reductions in the speed of sound of the inflaton
• Arbitrarily coupled $p-$forms in cosmological backgrounds
• New model of axion monodromy inflation and its cosmological implications
• Fingerprints of a Non-Inflationary Universe from Massive Fields
• Low-$\ell$ power suppression in punctuated inflation
• Consistency relations for sharp inflationary non-Gaussian features
• Pre-Inflationary Relics in the CMB?
• Finsler space-time can explain both parity asymmetry and power deficit seen in CMB temperature anisotropies
• Higher Order Corrections to Asymptotic-de Sitter Inflation
• Scale invariance of the primordial tensor power spectrum
• Shapes and features of the primordial bispectrum
• Large Angular Scale CMB Anisotropy from an Excited Initial Mode
• One spectrum to rule them all?
• Planckian hypersurfaces, inflation and bounces
• Investigating the Constraints on Primordial Features with Future Cosmic Microwave Background and Galaxy Surveys