CMB maximum temperature asymmetry axis: Alignment with other cosmic asymmetries
Abstract
We use a global pixel-based estimator to identify the axis of the residual Maximum Temperature Asymmetry (MTA) (after the dipole subtraction) of the WMAP seven-year Internal Linear Combination (ILC) cosmic microwave background temperature sky map. The estimator is based on considering the temperature differences between opposite pixels in the sky at various angular resolutions (4°-15°) and selecting the axis that maximizes this difference. We consider three large-scale HEALPix resolutions: Nside=16(3.7°), Nside=8(7.3°) and Nside=4(14.7°). We compare the direction and magnitude of this asymmetry with three other cosmic asymmetry axes (α dipole, dark energy dipole and dark flow) and find that the four asymmetry axes are abnormally close to each other. We compare the observed MTA axis with the corresponding MTA axes of 104 Gaussian isotropic simulated ILC maps (based on ΛCDM). The fraction of simulated ILC maps that reproduce the observed magnitude of the MTA asymmetry and alignment with the observed α dipole is in the range of 0.1%-0.5% (depending on the resolution chosen for the cosmic microwave background map). The corresponding magnitude+alignment probabilities with the other two asymmetry axes (dark energy dipole and dark flow) are at the level of about 1%. We propose Extended Topological Quintessence as a physical model qualitatively consistent with this coincidence of directions.
- Publication:
-
Physical Review D
- Pub Date:
- February 2013
- DOI:
- 10.1103/PhysRevD.87.043511
- arXiv:
- arXiv:1211.5915
- Bibcode:
- 2013PhRvD..87d3511M
- Keywords:
-
- 98.80.Es;
- 98.62.Sb;
- 98.65.Dx;
- Observational cosmology;
- Gravitational lenses and luminous arcs;
- Superclusters;
- large-scale structure of the Universe;
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- 8 pages, 6 figures. Typos corrected, references added. The data, Mathematica and Healpix-IDL program files used for the numerical analysis files may be downloaded from http://leandros.physics.uoi.gr/mta