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kitarist

Posts: 1715
Joined: Dec. 4 2012
 

RE: Black Hole eats sun (in reply to Ricardo

quote:

Nothing about dark energy in the abstract. It is about redshift of galaxy analysis. Similarly the evidence that implies “dark energy” or “accelerated expansion” is due to redshift anomaly. I often wondered if the data is corroborated by other “standard candles” than type 1A, and if not, how reliable are type 1A SN truly?

Paper:
https://iopscience.iop.org/article/10.3847/1538-4357/acac2e


There are two papers back to back - it is in the next one - link:

https://iopscience.iop.org/article/10.3847/2041-8213/acb704

ABSTRACT:
"Observations have found black holes spanning 10 orders of magnitude in mass across most of cosmic history. The Kerr black hole solution is, however, provisional as its behavior at infinity is incompatible with an expanding universe. Black hole models with realistic behavior at infinity predict that the gravitating mass of a black hole can increase with the expansion of the universe independently of accretion or mergers, in a manner that depends on the black hole's interior solution. We test this prediction by considering the growth of supermassive black holes in elliptical galaxies over 0 < z ≲ 2.5. We find evidence for cosmologically coupled mass growth among these black holes, with zero cosmological coupling excluded at 99.98% confidence. The redshift dependence of the mass growth implies that, at z ≲ 7, black holes contribute an effectively constant cosmological energy density to Friedmann's equations. The continuity equation then requires that black holes contribute cosmologically as vacuum energy. We further show that black hole production from the cosmic star formation history gives the value of ΩΛ measured by Planck while being consistent with constraints from massive compact halo objects. We thus propose that stellar remnant black holes are the astrophysical origin of dark energy, explaining the onset of accelerating expansion at z ∼ 0.7."

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Konstantin
  REPORT THIS POST AS INAPPROPRIATE |  Date Feb. 21 2023 17:23:25
 
devilhand

 

Posts: 1595
Joined: Oct. 15 2019
 

RE: Black Hole eats sun (in reply to Arash

Everytime I read the title of this thread, 2 things come to my mind. This song Black hole sun and pac man eating dots.





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Say No to Fuera de Compás!!!
  REPORT THIS POST AS INAPPROPRIATE |  Date Feb. 21 2023 18:08:22
 
Ricardo

Posts: 14794
Joined: Dec. 14 2004
From: Washington DC

RE: Black Hole eats sun (in reply to kitarist

quote:

with constraints from massive compact halo objects. We thus propose that stellar remnant black holes are the astrophysical origin of dark energy, explaining the onset of accelerating expansion at z ∼ 0.7."


Got it. Macho constraints (these were dark matter candidates too, though too few based on transit data). So there then is the “kick start” that appears in the historical Super Nova data, and I guess, because this contribution is so minuscule, (stellar mass black holes being so small compared to the Super Massive ones), the cosmo constant insanely weird tiny value (10 to the -120 smaller than Planck or something ridiculously tiny), it would make sense the contribution is from a small source creating the negative pressure observed.

We still need the mechanism (why not that they feed on the invisible dark matter then?).

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  REPORT THIS POST AS INAPPROPRIATE |  Date Feb. 22 2023 13:12:46
 
Fawkes

 

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Joined: Feb. 11 2015
 

RE: Black Hole eats sun (in reply to kitarist

  REPORT THIS POST AS INAPPROPRIATE |  Date Feb. 22 2023 17:25:32
 
Ricardo

Posts: 14794
Joined: Dec. 14 2004
From: Washington DC

RE: Black Hole eats sun (in reply to Fawkes

Right. But as I said, and she is ignoring, the einstein equation implies that the constant is balancing the books. But what the super nova data showed, which was surprising to everyone and still on the table, that after inflation stops, everything is expanding as normal, but suddenly there is a “kick start” and the acceleration begins. The new paper has found precise correlation between the kick start epoc onwards, accounted for by the stellar mass black holes (that did not exist before, but form due to stellar evolution), and the very precise yet tiny increase in expansion. Sabine thinks the correlation is “too good do be true” so to speak. And of course there is no mechanism understood yet that would explain how the growth and expansion are directly related.

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  REPORT THIS POST AS INAPPROPRIATE |  Date Feb. 23 2023 17:52:07
 
kitarist

Posts: 1715
Joined: Dec. 4 2012
 

RE: Black Hole eats sun (in reply to Fawkes

I don't know what she is on about; they have a whole section - 3.2 - and Appendices and Figure 2 working out whether the described black holes with non-singular vacuum-energy interiors can account for all the 'dark energy' and conclude that they can.

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Konstantin
  REPORT THIS POST AS INAPPROPRIATE |  Date Feb. 23 2023 19:24:50
 
Ricardo

Posts: 14794
Joined: Dec. 14 2004
From: Washington DC

RE: Black Hole eats sun (in reply to kitarist

quote:

ORIGINAL: kitarist

I don't know what she is on about; they have a whole section - 3.2 - and Appendices and Figure 2 working out whether the described black holes with non-singular vacuum-energy interiors can account for all the 'dark energy' and conclude that they can.


Actually this lady knows more about it as an expert on Super massive black hole growth. 31:50



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  REPORT THIS POST AS INAPPROPRIATE |  Date Feb. 25 2023 16:50:55
 
kitarist

Posts: 1715
Joined: Dec. 4 2012
 

RE: Black Hole eats sun (in reply to Ricardo

quote:

Actually this lady knows more about it as an expert on Super massive black hole growth. 31:50


Her main counter-argument seems to be in fact confirming that Farrah et al.'s finding is significant.

While, once formed, elliptical galaxies ( EGs) are "passive", making them great candidates for this kind of research, she says that Farrah et al. did not consider, in the construction of their "time sequence" made of observed EGs at various ages by redshift, that EGs formed in the early universe would essentially grow less before forming as an EG compared to more recently formed EGs because the young universe was structured differently:

"in the early Universe those galaxies are probably going to be a lot smaller very chaotic whereas it later on in the universe they've probably settled down into disc galaxies with spiral arms that can funnel material along them and grow the black hole before they merge together with something else and eventually form the elliptical galaxy"

She is saying this in arguing that the apparent result in Farrah (growth in mass relative to stellar mass by a factor of 8 to 20 with EG age) may be due to a difference in how EGs are formed depending on whether they were formed long time ago (early universe) versus later on.

But the ones formed in the early universe would be the ones that now would have the largest redshift i.e. be the oldest ones in the Farrah sequence, and vice versa. And yet, it is these older ones (formed in the younger universe) that show the biggest mass gain, factor of 20, compared to the younger ones (which should grow more according to her) that show a factor of 8.

So, I don't understand how the differential growth histories before forming as an elliptical galaxy are supposed to be an alternative explanation of the Farrah findings - the effect of that would be running the other way in terms of mass growth factor, so Farrah should not have found an increase from 8 to 20 with age; and yet they did.

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Konstantin
  REPORT THIS POST AS INAPPROPRIATE |  Date Feb. 27 2023 18:57:29
 
Ricardo

Posts: 14794
Joined: Dec. 14 2004
From: Washington DC

RE: Black Hole eats sun (in reply to kitarist

quote:

But the ones formed in the early universe would be the ones that now would have the largest redshift i.e. be the oldest ones in the Farrah sequence, and vice versa. And yet, it is these older ones (formed in the younger universe) that show the biggest mass gain, factor of 20, compared to the younger ones (which should grow more according to her) that show a factor of 8.


So, hmm. I think that is backwards…time does not run backwards. That would imply a DECREASE in mass as time moves forward anyway. Looking back means “long ago” or “old now”, but the things we see there are evolutionarily “young” compared to things we see nearby. The idea is that YOUNGER FROM OUR PERSPECTIVE high red shift ellipticals show lower masses than low red shift galaxies (nearby evolved OLD GALAXIES), assuming the ellipticals at ANY POINT IN TIME, don’t have material around them to evolve more, so consider/assume each one an evolutionary cul-de-sac. Since they are not mapping the literal time evolution, but infer that all other formational aspects were equal, they see GROWTH over time, not the opposite, so the younger ones will have grown more mass BY NOW, but that info has not reached us yet…it is inferred by the study. (If I have this wrong then I understand absolutely NOTHING )

She is saying that the assumption that the closer (older and more evolved) black holes that show growth via a mechanism OTHER than merger (elipticals don’t’ exist or evolve alone, they are ALL after-merger constructions), is ALREADY WELL KNOWN, but these mechanisms are NUMEROUS, and not clearly understood, and Farrah’s findings are just more of this non-merger growth on the huge pile.

Anyway, a lot of this is beside the point that it is the STELLAR MASS black holes appearance in the evolution of star formation that triggers the acceleration, i.e., more recently in history. At least that is THE important correlation the explains observations known since 1998. But as you know “correlation does not equal causation”.

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  REPORT THIS POST AS INAPPROPRIATE |  Date Mar. 3 2023 14:16:33
 
kitarist

Posts: 1715
Joined: Dec. 4 2012
 

RE: Black Hole eats sun (in reply to Ricardo

Oh I see, calling EGs formed in the early universe 'old' was confusing.

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Konstantin
  REPORT THIS POST AS INAPPROPRIATE |  Date Mar. 3 2023 20:14:59
 
Ricardo

Posts: 14794
Joined: Dec. 14 2004
From: Washington DC

RE: Black Hole eats sun (in reply to kitarist

quote:

ORIGINAL: kitarist

Oh I see, calling EGs formed in the early universe 'old' was confusing.


Perhaps not ironically, a few days ago, James Webb found 6 EG’s too massive to be allowed to exist THAT EARLY in the Universe. In other words, they imply that actually….they are the equivalent of “OLD” EGs after all. First thoughts are that the universe is quite a bit older than 13.8 billion, in order for the amount of time needed to pass for galaxy merger and evolution on that scale to occur. However, as Hossenfelder points out, this is actually a PREDICTION of the alternative solution to Dark Matter Wimps/Machos, called MOND (Modified Newtonian dynamics). I believe if this theory ends up having legs after all, then “red shift” studies like the blackholes over time thing, might also need updating.

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  REPORT THIS POST AS INAPPROPRIATE |  Date Mar. 4 2023 16:24:05
 
Ricardo

Posts: 14794
Joined: Dec. 14 2004
From: Washington DC

RE: Black Hole eats sun (in reply to kitarist

This guy says the 98% confidence regarding the coupling is actually a red flag. He traces the concepts through some other papers not mentioned earlier.



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  REPORT THIS POST AS INAPPROPRIATE |  Date Mar. 23 2023 11:31:05
 
Ricardo

Posts: 14794
Joined: Dec. 14 2004
From: Washington DC

RE: Black Hole eats sun (in reply to kitarist

A bit of a sharper image of M87 using algorithms based on assumptions (bias).



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  REPORT THIS POST AS INAPPROPRIATE |  Date Apr. 28 2023 11:59:12
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