Added 4/7/2007

Large Scale CMB
Mysteries at the Universe's Largest Observable Scales
by Dragan Huterer
2005 CMB Anomaly per U. of Chicago

As Commented on by Charles Sven, 2007

My comments are added in bold, italics or in red

"The Cosmological Principle states that the universe is homogeneous and isotropic on its largest scales. Nevertheless, this fundamental premise has only begun to be precision tested recently, with the advent of first large-scale maps of the cosmic microwave background anisotropy and galaxy surveys. Extraordinary full-sky maps produced by the WMAP experiment, in particular, are revolutionizing our ability to test the isotropy of the universe on its largest scales. Performing these tests is important because the universe at large scales probes a variety of physical processes, and in particular can be affected by the mysterious dark energy." This assumes that the conventional Big Bang interpretation is valid.

"The WMAP team's first year data confirmed the finding first found by the COBE satellite in early 1990s that the power at scales greater than about 60 degrees is essentially zero, in conflict with the prediction of the standard cosmological model. No convincing explanation for this lack of power has been found as of yet." The data do not match the expected symmetry.

"In addition, several other intriguing correlations have been found. Copi, Huterer and Starkman, together with Dominik Schwarz from Bielefeld University in Germany, found statistically significant and completely unexpected correlations of the CMB quadrupole and octopole with the ecliptic plane, (i.e., with the geometry and direction of motion of the solar system.) In particular, planes defined by the quadrupole and octopole are perpendicular to the ecliptic plane." A correlation of this data with the motion of the solar system would make one suspect that the CMB dipole anomaly itself might come from uncharted motions within the solar system, such as Brady's "Planet X", or Keller's Cassandra.

"These findings are complemented by those from other research groups, indicating that the CMB power in the south ecliptic hemisphere is larger than in the north, and that multipoles 4-7 also show alignments with an axis which is close to the dipole and equinox directions. The origin of these alignments is currently not understood, nor is it particularly clear if and how the various alignments are related."

"Understanding the origin of CMB anomalies is clearly important, as the observed alignments of power at large scales are inconsistent with predictions of standard cosmological theory. Regardless of whether the anomalies are caused by an instrumental, astrophysical or cosmological mechanism, many cosmological results from the CMB would need to be reconsidered as they depend on the information from large angular scales."

"They also eagerly expect new data, such as further WMAP temperature and polarization maps and observations and, in a few years, those from the PLANCK satellite. The mystery of the CMB anisotropy alignments on largest observable scales continues, and recent results have only whetted the appetite of cosmologists to explain the observed anomalies."

Regardless of origin, they don't fit in the standard model!

Further Reading

"Multipole Vectors - a new representation of the CMB sky and evidence for statistical anisotropy or non-Gaussianity at 2 <= L <= 8", C. Copi, D. Huterer and G. Starkman, Phys. Rev. D, 70, 043515 (2004)

"Is the Large-Scale Microwave Background Cosmic?", D. Schwarz, G. Starkman, D. Huterer and C. Copi, Phys. Rev. Lett., 93, 221301 (2004)

"On the large-angle anomalies of the microwave sky", C. Copi, D. Huterer, D. Schwarz and G. Starkman, MNRAS in press; astro-ph/0508047

"Spontaneous Symmetry Breaking: A Mechanism for CMB Multipole Alignments", C. Gordon, W. Hu, D. Huterer and T. Crawford, Phys. Rev. D, 72, 103003 (2005)

"Is the Universe out of Tune?", G. Starkman and D. Schwarz, Scientific American (August 2005)