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Buzz Bloom
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- TL;DR Summary
- A 5 Nov 2019 article gives as the calculated value of the radius of curvature of a closed universe to be 10 Gpc. Wikipedia gives the size of the observable universe as "about 14.3 billion parsecs".
These two independent sources have cosmological values that seriously contradict each other.
The article "Planck evidence for a closed Universe and a possible crisis for cosmology"
Paraphrasing Wikipedia: the radius of the observable universe is about 14.3 Gpc.
For this value Wikipedia cited a Scientific American Article for which the following has its abstract.
I am hoping someone here at the PFs can explain to me how the currently best value for the radius of a finite universe can be significantly smaller than the size of the observable universe. I understand that the four parameters of the two different ΛCDM models involved will be different, but I do not have access to sources for the values of these variables for these two models, so I cannot analyze how these variable values could produce this strange comparison.
ADDED
I just made an observation regarding the two results.
The value of the finite universe volume is 2π2RF3, and the volume of the observable universe is (4/3)πROU3.
Thus the ratio of volumes is
That is, the Finite universe is 1.6 times larger in volume than the Observable Universe. This relatively small ratio would have an effect on observing the CMB boundary, The finite universe CMB boundary would be about 1/2 the area that it would be in a flat universe.
I unintentionally cited an abstract rather than the whole article above. The link to a PDF file of the whole article is in my post #3.
AND STILL ANOTHER ADDED
My post #15 explains (briefly) my discovery of my conceptual errors regarding an aspect of this thread's curvature topic related to CMB watts per square meter detection.
The article "Planck evidence for a closed Universe and a possible crisis for cosmology"
arXiv:1911.02087v1 [astro-ph.CO] 5 Nov 2019
gives as the calculated value of the radius of curvature of a closed universe to be 10 Gpc. This value is based on a calculated 3.4 standard deviations range of values for the ΛCDM energy density parameter Ωk:-0.0007 < Ωk < -0.095 with a 99% confidence level.
Paraphrasing Wikipedia: the radius of the observable universe is about 14.3 Gpc.
For this value Wikipedia cited a Scientific American Article for which the following has its abstract.
I am hoping someone here at the PFs can explain to me how the currently best value for the radius of a finite universe can be significantly smaller than the size of the observable universe. I understand that the four parameters of the two different ΛCDM models involved will be different, but I do not have access to sources for the values of these variables for these two models, so I cannot analyze how these variable values could produce this strange comparison.
ADDED
I just made an observation regarding the two results.
The value of the finite universe volume is 2π2RF3, and the volume of the observable universe is (4/3)πROU3.
Thus the ratio of volumes is
VF/VOU = (3π/2) (10/14.3)3 = 1.6
That is, the Finite universe is 1.6 times larger in volume than the Observable Universe. This relatively small ratio would have an effect on observing the CMB boundary, The finite universe CMB boundary would be about 1/2 the area that it would be in a flat universe.
ANOTHER ADDEDI unintentionally cited an abstract rather than the whole article above. The link to a PDF file of the whole article is in my post #3.
AND STILL ANOTHER ADDED
My post #15 explains (briefly) my discovery of my conceptual errors regarding an aspect of this thread's curvature topic related to CMB watts per square meter detection.
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