CMB dipole asymmetry from a fast roll phase

Abstract

The observed CMB (cosmic microwave background) dipole asymmetry cannot be explained by a single field model of inflation - it inevitably requires more than one field where one of the fields is responsible for amplifying the super-Hubble fluctuations beyond the pivot scale. Furthermore the current constraints on $f_{N}L$ and $ta{u}_{N}L$ require that such an amplification cannot produce large non-Gaussianity. In this paper we propose a model to explain this dipole asymmetry from a spectator field, which is responsible for generating all the curvature perturbations, but has a temporary fast roll phase before the Hubble exit of the pivot scale. The current data prefers spectator scenario because it leaves no isocurvature perturbations. The spectator model will also satisfy the well-known constraints arising from quasars, and the quadrupole and octupole of the CMB.

15 pages, 5 figures, revision accepted by JCAP

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Cited by in corpus (34)

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• CMB Power Asymmetry from Primordial Sound Speed Parameter
• Large-scale anomalies in the cosmic microwave background as signatures of non-Gaussianity
• Inflationary power asymmetry from primordial domain walls
• CMB Hemispherical Asymmetry: Long Mode Modulation and non-Gaussianity
• Constraining $\mathcal{N}=1$ supergravity inflation with non-minimal Kähler operators using $\delta N$ formalism
• Pre-inflationary primordial perturbations
• Hemispherical Power Asymmetry from a Space-Dependent Component of the Adiabatic Power Spectrum
• Scale-dependent non-Gaussianity and the CMB Power Asymmetry
• Expected dipole asymmetry in CMB polarization
• Isotropization of the universe during inflation
• The hemispherical asymmetry from a scale-dependent inflationary bispectrum
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• Hemispherical Power Asymmetry from Scale-Dependent Modulated Reheating
• Relating the inhomogeneous power spectrum to the CMB hemispherical anisotropy
• CMB hemispherical asymmetry from non-linear isocurvature perturbations
• Imprint of Inhomogeneous and Anisotropic Primordial Power Spectrum on CMB Polarization
• Lensing as a Probe of Early Universe: from CMB to Galaxies
• Anisotropic cosmology and inflation from tilted Bianchi IX model
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• Primordial anisotropies from cosmic strings during inflation
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• Primordial inhomogeneities from massive defects during inflation
• Noncommutative Geometry and the Primordial Dipolar Imaginary Power Spectrum
• Isotropic non-Gaussian $g_{\mathrm{NL}}$-like toy models that reproduce the cosmic microwave background anomalies
• Cosmic Microwave Background Dipole Asymmetry could be explained by Axion Monodromy Cosmic Strings
• CMB Polarization by the Asymmetric Template of Scalar Perturbations
• Detecting CMB modulations and non-Gaussianities from power multipoles
• Spectator fields and their imprints on the Cosmic Microwave Background
• Hidden in the background: a local approach to CMB anomalies
• Dipole Modulation in Tensor Modes: Signatures in CMB Polarization