publication . Preprint . Article . 2016

How isotropic is the Universe?

Daniela Saadeh; Stephen M. Feeney; Andrew Pontzen; Hiranya V. Peiris; Jason D. McEwen;
Open Access English
  • Published: 23 May 2016
A fundamental assumption in the standard model of cosmology is that the Universe is isotropic on large scales. Breaking this assumption leads to a set of solutions to Einstein's field equations, known as Bianchi cosmologies, only a subset of which have ever been tested against data. For the first time, we consider all degrees of freedom in these solutions to conduct a general test of isotropy using cosmic microwave background temperature and polarization data from Planck. For the vector mode (associated with vorticity), we obtain a limit on the anisotropic expansion of $(\sigma_V/H)_0 < 4.7 \times 10^{-11}$ (95% CI), which is an order of magnitude tighter than p...
Persistent Identifiers
arXiv: Astrophysics::Cosmology and Extragalactic Astrophysics
free text keywords: Astrophysics - Cosmology and Nongalactic Astrophysics, General Relativity and Quantum Cosmology, CMB cold spot, Universe, media_common.quotation_subject, media_common, Astrophysics, Cosmic microwave background, Physics, COSMIC cancer database, Polarization (waves), Anisotropy, Isotropy
Funded by
Understanding the Origin of Cosmic Structure
  • Funder: European Commission (EC)
  • Project Code: 306478
  • Funding stream: FP7 | SP2 | ERC
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