skip to main content

SciTech ConnectSciTech Connect

Title: CMB dipole asymmetry from a fast roll phase

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{sub NL} and τ{sub NL} 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.
Authors:
;  [1]
  1. Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom)
Publication Date:
OSTI Identifier:
22282605
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2013; Journal Issue: 10; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLIFICATION; ASYMMETRY; DIPOLES; FLUCTUATIONS; INFLATIONARY UNIVERSE; INFLATONS; LIMITING VALUES; OCTUPOLES; PERTURBATION THEORY; QUASARS; RELICT RADIATION