Corrections to the Cosmic Microwave Map (can anyone clarify?)

[Martin]

I'd appreciate any opinion or clarification about this

 

For starters there's this popularization in CERN COURIER

http://www.cerncourier.com/main/article/44/10/4

 

And then there are a couple of technical papers, one of which just came out this month.

 

http://www.arxiv.org/abs/astro-ph/0403353

Is the low-l microwave background cosmic?

Dominik J. Schwarz (CERN), Glenn D. Starkman (CERN, Case Western Reserve University), Dragan Huterer (CWRU), Craig J. Copi (CWRU)

4 pages, 3 figures; more figures available at:

http://www.phys.cwru.edu/projects/mpvectors/

Phys.Rev.Lett. 93 (2004) 221301

The large-angle (low-l) correlations of the Cosmic Microwave Background exhibit several statistically significant anomalies compared to the standard inflationary big-bang model, however no connection has hitherto been drawn between them. Here we show that the quadrupole and octopole are far more correlated (99.97% C.L.) than previously thought. The quadrupole plane and the three octopole planes are remarkably aligned. Three of these planes are orthogonal to the ecliptic at a level inconsistent with gaussian random statistically isotropic skies at 99.8% C.L., and the normals to these planes are aligned at 99.9% C.L. with the direction of the cosmological dipole and with the equinoxes. The remaining octopole plane is orthogonal to the supergalactic plane at >99.9% C.L. In a combined quadrupole-octopole map, the ecliptic plane narrowly threads between a hot spot and a cold spot over approximately 1/3 of the sky, and separates the three strongest extrema (in the south ecliptic hemisphere) from the three weakest extrema (in the north ecliptic hemisphere)."

 

http://www.arxiv.org/abs/astro-ph/0508047/

On the large-angle anomalies of the microwave sky

C. J. Copi (1), D. Huterer (2), D. J. Schwarz (3), G. D. Starkman (1) ((1) Case Western Reserve University, (2) University of Chicago, (3) Universitat Bielefeld)

26 pages, 7 figures. High resolution figures, multipole vector code and other information can be found at:

http://www.phys.cwru.edu/projects/mpvectors/

[Abridged] "We apply the multipole vector framework to full-sky maps derived from the first year WMAP data. We significantly extend our earlier work showing that the two lowest cosmologically interesting multipoles, l=2 and 3, are not statistically isotropic. These results are compared to the findings obtained using related methods. In particular, the planes of the quadrupole and the octopole are unexpectedly aligned. Moreover, the combined quadrupole plus octopole is surprisingly aligned with the geometry and direction of motion of the solar system: the plane they define is perpendicular to the ecliptic plane and to the plane defined by the dipole direction, and the ecliptic plane carefully separates stronger from weaker extrema, running within a couple of degrees of the null-contour between a maximum and a minimum over more than 120deg of the sky. Even given the alignment of the quadrupole and octopole with each other, we find that their alignment with the ecliptic is unlikely at >98% C.L., and argue that it is in fact unlikely at >99.9% C.L. We explore the role of foregrounds showing that the known Galactic foregrounds are unlikely to lead to these correlations. Multipole vectors, like individual a_lm, are very sensitive to sky cuts, and we demonstrate that analyses using cut skies induce relatively large errors, thus weakening the observed correlations but preserving their consistency with the full-sky results. Finally we apply our tests to COBE cut-sky maps and briefly extend the analysis to higher multipoles. If the correlations we observe are indeed a signal of non-cosmic origin, then the lack of low-l power will very likely be exacerbated, with important consequences for our understanding of cosmology on large scales."

[Severian]

I think this is very interesting. This could be evidence for large scale structure in the universe, which could blow standard big bang models right out of the water. It is particularly dangerous for inflation because you would have expected these structures to be removed by inflation.

 

It is most likely just showing a systematic error in the WMAP data though, since the structure seem to be correlated with the solar system's axis. I doubt that there really is large scale structure in the CMBR.