2014/08/31 by Sadra Jazayeri, Yashar Akrami, Hassan Firouzjahi +2
Physics and Astronomy · #Cosmology and Gravitation Theories #Electrical and Electromagnetic Research #Galaxies: Formation, Evolution, Phenomena #astro-ph.CO #hep-th
paper · pdf · doi:10.1088/1475-7516/2014/11/044
published as JCAP 1411 (2014) 044 · 22 pages, 7 figures. Version published in JCAP
openalex publication_date 2014/11/28 · arxiv created 2014/11/29 · arxiv updated 2014/12/02 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We study the asymmetric primordial fluctuations in a model of inflation in which translational invariance is broken by a domain wall. We calculate the corrections to the power spectrum of curvature perturbations; they are anisotropic and contain dipole, quadrupole, and higher multipoles with non-trivial scale-dependent amplitudes. Inspired by observations of these multipole asymmetries in terms of two-point correlations and variance in real space, we demonstrate that this model can explain the observed anomalous power asymmetry of the cosmic microwave background (CMB) sky, including its characteristic feature that the dipole dominates over higher multipoles. We test the viability of the model and place approximate constraints on its parameters by using observational values of dipole, quadrupole, and octopole amplitudes of the asymmetry measured by a local-variance estimator. We find that a configuration of the model in which the CMB sphere does not intersect the domain wall during inflation provides a good fit to the data. We further derive analytic expressions for the corrections to the CMB temperature covariance matrix, or angular power spectra, which can be used in future statistical analysis of the model in spherical harmonic space.