Graduate Is the CMBR interpretation for dark matter a fudge?

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SUMMARY

The discussion centers on the diminishing likelihood of dark matter as a viable explanation for astronomical phenomena, particularly in light of recent failed detection experiments such as LUX (2016), PandaX II (2017), and Xenon1T (2018). Notably, researchers J. Jalocha, F. Cooperstock, and A. Deur propose alternatives to explain galaxy rotation curves without invoking dark matter. Despite these challenges, the Planck mission continues to assert a dark matter density parameter Ωc h² of 0.12 ± 0.001, raising questions about the robustness of the underlying models. The conversation emphasizes the need for clarity regarding the two-point function Cl, which is crucial for understanding the cosmic microwave background (CMB) data.

PREREQUISITES
  • Understanding of cosmic microwave background (CMB) data and its significance in cosmology
  • Familiarity with dark matter detection experiments, specifically LUX, PandaX II, and Xenon1T
  • Knowledge of galaxy rotation curves and their implications for dark matter theories
  • Basic grasp of the two-point correlation function Cl and its role in analyzing CMB anisotropies
NEXT STEPS
  • Research the implications of the Planck mission's findings on dark matter density and the LCDM model
  • Study the methodologies used in LUX, PandaX II, and Xenon1T experiments for dark matter detection
  • Examine the works of J. Jalocha, F. Cooperstock, and A. Deur for alternative theories to dark matter
  • Learn about the mathematical formulation of the two-point function Cl and its application in CMB analysis
USEFUL FOR

Astronomers, cosmologists, and physicists interested in the ongoing debate surrounding dark matter, as well as researchers seeking to understand the implications of CMB data on cosmological models.

  • #31
EigenState137 said:
Why the belligerence towards both those who have attempted to be of assistance here and the scientific community in general?

WMAP publications

Planck publications
Apologies, if you think my response belligerent. It was not intended. I may have inadvertently stumbled on an answer to my question.
 
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  • #32
Adrian59 said:
I would have thought it was obvious that I have studied and read some advanced cosmology from the references I have given in the thread.
Throwing references around is not the same as having reached a proper understanding of those references. So, no, it has definitely not been obvious from how you have generally expressed yourself in this thread that you have understood what you have studied and read. If you had, you would have known that the way to get the prediction for the power spectrum is essentially to consider the Fourier modes of the density perturbations and how these transfer to the surface of last scattering. You would also know that there are a large number of effects influencing the density perturbations in the early Universe and that not all of them can be easily put on a "concise form" as you seem to want.
 
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  • #33
Adrian59 said:
If you can give some more mathematical pointers to the theoretical model rather than repeat the narrative, or even suggest a good reference paper, that would go some way towards settling the issue.
I can give you some references, but I won't be able to help you understand them. You can start here for an overview:
https://www.roe.ac.uk/ifa/postgrad/pedagogy/2006_tojeiro.pdf
Wayne Hu's PhD thesis goes into the gory details:
http://background.uchicago.edu/~whu/Papers/thesis.pdf
Both Peeble's and Peacock's texts go over the physics, but they're extremely dense.
 
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  • #34
Orodruin said:
Throwing references around is not the same as having reached a proper understanding of those references. So, no, it has definitely not been obvious from how you have generally expressed yourself in this thread that you have understood what you have studied and read. If you had, you would have known that the way to get the prediction for the power spectrum is essentially to consider the Fourier modes of the density perturbations and how these transfer to the surface of last scattering. You would also know that there are a large number of effects influencing the density perturbations in the early Universe and that not all of them can be easily put on a "concise form" as you seem to want.
At last I feel we are getting somewhere. Quickly dealing with your first sentence, I can reassure you that if I quote a reference it is one I have read and understood. I would like to add that until now only I have included any references. Moving to some physics, you mention density perturbations but which of these are you referring to?
However, it appears that another contributor to this thread has provided some references which I would like to check before making any further comment.
 
  • #36
Adrian59 said:
What appears obvious to you is because you have bought into this narrative
This attitude is not going to lead to a productive discussion. Thread closed.