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Title: Isotropy of the early universe from CMB anisotropies

Abstract

The acoustic peak in the cosmic microwave background power spectrum is sensitive to causal processes and cosmological parameters in the early universe up to the time of last scattering. We provide limits on correlated spatial variations of the peak height and peak position and interpret these as constraints on the spatial variation of the cosmological parameters (baryon density, cold dark matter density, and cosmological constant as well as the amplitude and tilt of the original fluctuations). We utilize recent work of Hansen, Banday, and Gorski who have studied the spatial isotropy of the power spectrum as measured by WMAP by performing the power spectrum analysis on smaller patches of the sky. We find that there is no statistically significant correlated asymmetry of the peak. Hansen, Banday, and Gorski have also provided preliminary indications of a preferred direction in the lower angular momentum range (l{approx}2-40) and we show how possible explanations of this asymmetry are severely constrained by the data on the acoustic peak. Finally we show a possible non-Gaussian feature in the data, associated with a difference in the northern and southern galactic hemispheres.

Authors:
 [1];  [2];  [1]
  1. Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
20705982
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 71; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevD.71.043002; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; ANGULAR MOMENTUM; ANISOTROPY; ASYMMETRY; BARYONS; COSMOLOGICAL CONSTANT; COSMOLOGY; DENSITY; FLUCTUATIONS; ISOTROPY; NONLUMINOUS MATTER; RELICT RADIATION; SCATTERING; UNIVERSE

Citation Formats

Donoghue, Evan P., University of Notre Dame, Notre Dame, Indiana 46556, and Donoghue, John F. Isotropy of the early universe from CMB anisotropies. United States: N. p., 2005. Web. doi:10.1103/PhysRevD.71.043002.
Donoghue, Evan P., University of Notre Dame, Notre Dame, Indiana 46556, & Donoghue, John F. Isotropy of the early universe from CMB anisotropies. United States. doi:10.1103/PhysRevD.71.043002.
Donoghue, Evan P., University of Notre Dame, Notre Dame, Indiana 46556, and Donoghue, John F. Tue . "Isotropy of the early universe from CMB anisotropies". United States. doi:10.1103/PhysRevD.71.043002.
@article{osti_20705982,
title = {Isotropy of the early universe from CMB anisotropies},
author = {Donoghue, Evan P. and University of Notre Dame, Notre Dame, Indiana 46556 and Donoghue, John F.},
abstractNote = {The acoustic peak in the cosmic microwave background power spectrum is sensitive to causal processes and cosmological parameters in the early universe up to the time of last scattering. We provide limits on correlated spatial variations of the peak height and peak position and interpret these as constraints on the spatial variation of the cosmological parameters (baryon density, cold dark matter density, and cosmological constant as well as the amplitude and tilt of the original fluctuations). We utilize recent work of Hansen, Banday, and Gorski who have studied the spatial isotropy of the power spectrum as measured by WMAP by performing the power spectrum analysis on smaller patches of the sky. We find that there is no statistically significant correlated asymmetry of the peak. Hansen, Banday, and Gorski have also provided preliminary indications of a preferred direction in the lower angular momentum range (l{approx}2-40) and we show how possible explanations of this asymmetry are severely constrained by the data on the acoustic peak. Finally we show a possible non-Gaussian feature in the data, associated with a difference in the northern and southern galactic hemispheres.},
doi = {10.1103/PhysRevD.71.043002},
journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 4,
volume = 71,
place = {United States},
year = {2005},
month = {2}
}