PIRSA:08100031 Scientific Series Cosmology

DOI10.48660/08100031

Series: Cosmology and Gravitation

Erickcek, A. (2008). Structure Beyond the Horizon: Inflationary Origins of the Cosmic Power Asymmetry. Perimeter Institute. https://pirsa.org/08100031

Erickcek, Adrienne. Structure Beyond the Horizon: Inflationary Origins of the Cosmic Power Asymmetry. Perimeter Institute, Oct. 14, 2008, https://pirsa.org/08100031 

@misc{ pirsa_PIRSA:08100031,
  doi = {10.48660/08100031},
  url = {https://pirsa.org/08100031},
  author = {Erickcek, Adrienne},
  keywords = {Cosmology},
  language = {en},
  title = {Structure Beyond the Horizon: Inflationary Origins of the Cosmic Power Asymmetry},
  publisher = {Perimeter Institute},
  year = {2008},
  month = {oct},
  note = {PIRSA:08100031 see, \url{https://pirsa.org}}
}

Abstract

WMAP measurements of CMB temperature anisotropies reveal a power asymmetry: the average amplitude of temperature fluctuations in one hemisphere is larger than the average amplitude in the opposite hemisphere at the 99% confidence level. This power asymmetry may be generated during inflation by a large-amplitude superhorizon perturbation that causes the mean energy density to vary across the observable Universe. Such a superhorizon perturbation would also induce large-scale temperature anisotropies in the CMB; measurements of the CMB quadrupole and octupole (but not the dipole!) therefore constrain the perturbation\'s amplitude and wavelength. I will show how a superhorizon perturbation in a multi-field inflationary theory, the curvaton model, can produce the observed power asymmetry without generating unacceptable temperature fluctuations in the CMB. I will also discuss how this mechanism for generating the power asymmetry will be tested by forthcoming CMB experiments.

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