An explanation for hemispherical anisotropy in the CMB?

In summary, this paper suggests a possible explanation for hemispherical anisotropy in the CMB based on non-commutative space time. This sounds interesting but I am surprised to see a NCG paper which cites Connes only once in its bibliography (and that is for a 1994 textbook - 1990 for the original edition I believe).
  • #1
Chronos
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This paper, http://arxiv.org/abs/1503.03859, suggests a possible explanation for hemispherical anisotropy in the CMB based on non-commutative space time.
 
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  • #2
This sounds interesting but I am surprised to see a NCG paper which cites Connes only once in its bibliography (and that is for a 1994 textbook - 1990 for the original edition I believe).
 
  • #3
Hi Chronos and Wabbit, it does sound interesting. I'm always interested in the people and the name Pankaj Jain rang a bell so I looked him up:
http://inspirehep.net/author/profile/P.Jain.1
He seems to be specialized in phenomenology and has several papers about dipole anisotropy, as if fascinated by the idea of cosmos having a large scale asymmetry.
He has a good track record of publication and citation.
And he got his PhD in 1988 from SYRACUSE which I think was where Ashtekar was at the time. Possibly an inspiring place at that time. After PhD he didn't bounce around much. After 1993 or so, he basically just settled on the faculty of an institute of technology (engineering school) in India and stayed there. He could be good. As a cosmology phenomenologist he doesn't necessarily have to master and employ the latest of Alain Connes results, he just has to get one idea and apply it to the cosmos and see if it fits.
That's all superficial--people interest/human interest. I'll go look at the paper itself which is the real thing that matters. Sounds weird, doesn't it!
 
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  • #4
I looked at the article and didn't get a favorable impression--but I'm not an expert so that doesn't mean very much. It seemed to me that this article is basically a WARMED OVER version of its reference [19]
http://arxiv.org/pdf/1407.1714v1.pdf
Noncommutative Geometry and the Primordial Dipolar Imaginary Power Spectrum
Pankaj Jain and Pranati K. Rath July 8, 2014
Dept. of Physics, Indian Institue of Technology Kanpur, Kanpur - 208016, India
Abstract
We argue that an anisotropic dipolar imaginary primordial power spectrum is possible within the framework of noncommutative space-times. We show that such a spectrum provides a good description of the observed dipole modulation in CMBR data. We extract the corresponding power spectrum from data. The dipole modulation is related to the observed hemispherical anisotropy in CMBR data, which might represent the first signature of quantum gravity.
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It looked to me as if reference [19] was where they do their real calculations, and over and over, in http://arxiv.org/abs/1503.03859, they cite two seminal papers by other people [15] and [16] and then they immediately afterwards cite [17 - 19] which includes their own work [19]. That seems to be where the meat is. In this 2015 one they don't get substantially new results they just cite [19] and other sources.
 
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  • #5
Thanks marcus - more or less expected something like that based on my quick biblio check but was too lazy to do a more thorough investigation, and waited for someone qualified to step in:)
 

Related to An explanation for hemispherical anisotropy in the CMB?

1. What is hemispherical anisotropy in the CMB?

Hemispherical anisotropy in the Cosmic Microwave Background (CMB) refers to the uneven distribution of temperature fluctuations across the sky, where one half of the sky appears warmer or cooler than the other half.

2. What causes hemispherical anisotropy in the CMB?

The most widely accepted explanation for hemispherical anisotropy in the CMB is inflation, a period of rapid expansion in the early universe. This inflationary period would have caused tiny quantum fluctuations to be stretched across the universe, resulting in the uneven distribution of temperature fluctuations in the CMB.

3. How is hemispherical anisotropy in the CMB measured?

Hemispherical anisotropy in the CMB is measured through observations made by satellites and ground-based telescopes. These observations measure the temperature fluctuations in the CMB and create maps of the sky, which can reveal the uneven distribution of temperature across the sky.

4. What are the implications of hemispherical anisotropy in the CMB?

The presence of hemispherical anisotropy in the CMB supports the theory of inflation and provides insight into the early universe. It also suggests that the universe is not perfectly isotropic, or the same in all directions, which challenges some models of the universe.

5. Are there other possible explanations for hemispherical anisotropy in the CMB?

While the inflationary model is the most widely accepted explanation for hemispherical anisotropy in the CMB, there are other proposed explanations, such as cosmic defects or the influence of large-scale structures in the universe. However, these alternative explanations are not as well-supported by observational evidence as the inflationary model.

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