CMB Hemispherical Asymmetry: Long Mode Modulation and non-Gaussianity

Abstract

The observed hemispherical asymmetry in CMB map can be explained by modulation from a long wavelength super horizon mode which non-linearly couples to the CMB modes. We address the criticism in [1] about the role of non-Gaussianities in squeezed and equilateral configurations in generating hemispherical asymmetry from the long mode modulation. We stress that the modulation is sensitive to the non-Gaussianity in the squeezed limit. In addition, we demonstrate the validity of our approach in providing a consistency condition relating the amplitude of dipole asymmetry to f_{NL} in the squeezed limit.

References added, JCAP published version

References in corpus (10)

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Cited by in corpus (10)

• Inflationary power asymmetry from primordial domain walls
• Pre-inflationary primordial perturbations
• Expected dipole asymmetry in CMB polarization
• A separate universe view of the asymmetric sky
• Generating the cosmic microwave background power asymmetry with $g_{NL}$
• Late time sky as a probe of steps and oscillations in primordial Universe
• CMB hemispherical asymmetry from non-linear isocurvature perturbations
• Fingerprints of Anomalous Primordial Universe on the Abundance of Large Scale Structures
• Long gradient mode and large-scale structure observables
• Dipole Modulation in Tensor Modes: Signatures in CMB Polarization