A dynamic form of dark energy may explain strange radiation signal from the early universe

[Admin]

We may have already found evidence of an evolving, dynamic kind of dark energy, in the form of the radiation emitted when the first stars appeared in the universe.

A dynamic form of dark energy may explain strange radiation signal from the early universe : Read more

 

[rod]

Quite a report here for BB cosmology, perhaps finding the 21-cm line for the Epoch of Reionization I note this about the nature of dark energy reported here in the space.com article.

"Yin's work, published to the preprint database arXiv, explored a model called interacting Chevallier-Polarski-Linder dark energy, or ICPL. In this model, dark energy is not a fixed constant of the cosmos but a dynamical entity that can change and evolve in time, resulting in changes in the acceleration rate of expansion. But that ability to evolve immediately opens up a question: What controls the way dark energy can change? In response, this model allows for dark energy to interact with dark matter; their behavior is linked, keeping both of them in check as the universe expands."

My view, this model looks very convenient here for the behavior or dark energy and dark matter in BB cosmology, *keeping both of them in check as the universe expands.*

I note this about the redshift reported too, z about 17, a very deep redshift. https://arxiv.org/pdf/2305.20038.pdf, "I. INTRODUCTION The Experiment to Detect the Global Epoch of Reionization Signature (EDGES) has reported the detection of an absorption profile centered at 78 MHz [1], corresponding to a redshift z ≈ 17, which is named the global 21-cm signal."

My note, redshift about 17 using cosmology calculators (https://lambda.gsfc.nasa.gov/toolbox/calculators.html) puts us way out there from Earth 13.494 billion light years look back distance and age of universe at z=17, 0.228 Gyr. The comoving radial distance is even much farther away from Earth today 34.941 Gly so space expands 2.4339135E+00 or 2.43 x c velocity. Has JWST confirmed redshifts of objects at 17 or larger? So far, I have not seen any published confirmations of such large redshifts being seen by JWST. Lyman break method and spectroscopic method. The space.com report does close with. "This is an intriguing result, but not a slam dunk. The 21-cm observations are still in dispute, and there are other possible explanations for the strange signal. Still, this shows how scientists can approach observations like this and continue to push into the frontiers of understanding dark energy and dark matter."

 

[Unclear Engineer]

It seems like there is a lot of room between z=17 and the CMBR at 1089. If indeed there was elemental or molecular hydrogen in space between those times, from which the stars formed, shouldn't we be able to look back past z=17 with a powerful enough telescope tuned to the right frequencies to see the red-shifted light from the earliest stars?

Also, what is the basis for the article saying
"the universe has expanded to be about 10 times its previous size. That expansion has stretched the wavelength of that 21-cm radiation, and today, it's now detectable in radio wavelengths. In 2018, a team of astronomers claimed to have detected the 21-cm signal emitted when the universe was only 230 million years old."

Isn't the scale factor more like 1089 for the CMBR and 17 for reionization? Or am I the one confused by the way these parameters get bandied about in the lay media?

 

[rod]

Concerning Unclear Engineer post #3, I look and use the cosmology calculators that makes it easier to see the FLRW math in GR for expansion. We have the look back distance or light time distance from Earth today, the comoving radial distance, and the angular size of the universe radius too. A redshift of 17 shows the radius of the universe to be about 1.94 Gly so diameter about 4 Gly across compared to the present size, now considered to be some 93 Gly diameter using comoving radial distance and using look back distance, about 27 Gly diameter as seen and measured from Earth. As you have pointed out in the past, where is the H-alpha line in the CMBR, I also ask for He too. I have reports that show redshifts in BB cosmology are calculated out to 3 million or more for the z values, well before CMBR forms with redshift near 1090-1100 used.

 

[rod]

FYI, using cosmology calculators and z=1100 for CMBR redshift, universe radius about 41 Mly so diameter then about 82 Mly across. Redshift of 17, universe radius about 1.94 Gly so diameter about 4 Gly. As post #3 called attention too, [Also, what is the basis for the article saying "the universe has expanded to be about 10 times its previous size. That expansion has stretched the wavelength of that 21-cm radiation, and today, it's now detectable in radio wavelengths. In 2018, a team of astronomers claimed to have detected the 21-cm signal emitted when the universe was only 230 million years old."]

From the radius of the universe when CMBR becomes light to the radius of the universe at z=17, we have space expanding much faster than c velocity here too Just consider the size change in light-years and a time period of 300 Myr.

 

[rod]

It seems like there is a lot of room between z=17 and the CMBR at 1089. If indeed there was elemental or molecular hydrogen in space between those times, from which the stars formed, shouldn't we be able to look back past z=17 with a powerful enough telescope tuned to the right frequencies to see the red-shifted light from the earliest stars?

Also, what is the basis for the article saying
"the universe has expanded to be about 10 times its previous size. That expansion has stretched the wavelength of that 21-cm radiation, and today, it's now detectable in radio wavelengths. In 2018, a team of astronomers claimed to have detected the 21-cm signal emitted when the universe was only 230 million years old."

Isn't the scale factor more like 1089 for the CMBR and 17 for reionization? Or am I the one confused by the way these parameters get bandied about in the lay media?

"It seems like there is a lot of room between z=17 and the CMBR at 1089."

IMO, that is a very good statement here. The *natural* evolution of the universe from the time the CMBR appears as light in BB model until z=17 in the report cited, the size of the universe expands much faster than c in BB model. This period of cosmic evolution seems difficult to see today from Earth