Cosmic Microwave Background primer

AI Thread Summary
The discussion centers on the Cosmic Microwave Background (CMB) and critiques a mini-review paper for lacking critical analysis, particularly regarding the low multipole mode deficiency and the missing Sachs-Wolfe plateau. Participants express concerns about the interpretation of CMB data, including the "axis of evil" phenomenon, which could alter conclusions drawn from the findings. There is anticipation for the release of WMAP year 2 results, with a mention of a forthcoming paper addressing large-scale CMB anisotropies and their implications. The conversation highlights the need for improved instrument sensitivity to better understand these anomalies. Overall, the dialogue emphasizes the complexities and ongoing debates surrounding CMB research.
Chronos
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As a fan of easy reading material on thorny topics, I thought some might find this interesting:

http://www.arxiv.org/abs/astro-ph/0601307
Cosmic Microwave Background Mini-Review
 
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Thank you Chronos - nice paper, though I thought it could have been a little more critical and included caveats where appropiate: no discussion of the low-l mode deficiency instead it says:"
We have suppressed some of the low-ℓ and high-ℓ band-powers which have large error bars.
...
The multipole axis here is linear, so the Sachs-Wolfe plateau is hard to see.
and does not mention the fact that the S-W plateau is actually missing. No discussion about the 'axis of evil', the effect of which may completely change the interpretation put upon the data.

And when is the WMAP year 2 release date?

Garth
 
Agreed. But, you must admit you are a bit more advanced [and demanding] than most audiences, Garth. You like the tough stuff. Personally, I think the SW plateau is missing because instrument sensitivity is just not as good as hoped. WMAP year 2 results should be released a week from friday . . .
 
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Chronos said:
WMAP year 2 results should be released a week from friday . . .
I've heard that one before...:wink:

Garth
 
Chronos said:
WMAP year 2 results should be released a week from friday . . .
Wow! Is this official?
 
They have not yet announced which friday . . .
 
A paper today on the large scale, low l-mode CMB anisotropies, accepted for publication in A&A:
On the CMB large-scales angular correlations
We found that the, already known, anomalous lack of large-scale power in full-sky CMB maps are mainly due to missing angular correlations of quadrupole-like signature. This result is robust with respect to frequency CMB maps and cut-sky masks. Moreover, we also confirm previous results regarding the unevenly distribution in the sky of the large-scale power of WMAP data. In a bin-to-bin correlations analyses, measured by the full covariance matrix chi^2 statistic, we found that the angular correlations signatures in opposite Galactic hemispheres are anomalous at the 98%-99% confidence level.

Garth
 
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