How dark energy could relieve 'Hubble tension' and galaxy headaches

This article is useless for explaining anything. But, it is a great example for how much the "standard" cosmological model simply invokes additional unexplained energy parameters to make it fit observations. At this point, there are really 3 different, unexplained, unconnected, "extra" energy concepts: the one that caused initial "inflation", the one that most recently causes accelerated expansion of the universe, and now this "early version" which supposedly:

"In principle, early dark energy should have been similar to the dark energy driving the expansion of the universe today. The difference, however, would be that, while modern dark energy began acting around 4 billion years ago, early dark energy would have appeared briefly in the early cosmos just thousands of years after the Big Bang. Then, it would have disappeared entirely. [emphasis added]

Nothing about why or how, so not an explanation.

And, further on, it states:

"It is unclear just how early dark energy could have led to the early formation of large galaxies in the infant universe — yet, the fact that this model could kill two cosmic birds with one stone means the team thinks it's worth pursuing."

So, they are already assuming that they can somehow find a way to claim that "early dark energy" can solve this problem, too, without even claiming to have done so , yet!!!

I guess that is a good assumption, considering that it is based on being able to imagine anything without having to explain it with physics that anybody actually understands.

But, to me, "explaining" an observation with an "explanation" that is simply putting another name on something that nobody understands is not an explanation at all.
 
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"In principle, early dark energy should have been similar to the dark energy driving the expansion of the universe today. The difference, however, would be that, while modern dark energy began acting around 4 billion years ago, early dark energy would have appeared briefly in the early cosmos just thousands of years after the Big Bang. Then, it would have disappeared entirely. [emphasis added]

Nothing about why or how, so not an explanation.
Agreed. Besides, what's special at about 2k years after t=0? Almost any extra DE imagined could be assumed prior to Recombination (375k yrs. after t=0).

If they offer no physics to support their acceleration bump, it will appear ad hoc.

But not all "fixes" to BBT are ad hoc. The key is whether or not a fix produces a confluence with other lines of evidence. I don't see this fix doing this.

It's still unclear to me why DE in general doesn't explain the tension. Lemaitre's 1927 paper showed acceleration because he wouldn't dismiss the logic and elegance of Einstein's cosmological constant, though Einstein dumped it.

"It is unclear just how early dark energy could have led to the early formation of large galaxies in the infant universe — yet, the fact that this model could kill two cosmic birds with one stone means the team thinks it's worth pursuing."
Ok. That would make it look a little more credible, I suppose.

So, they are already assuming that they can somehow find a way to claim that "early dark energy" can solve this problem, too, without even claiming to have done so , yet!!!
Well, even I've been saying DE should solve it for quite a while. As I've stated in the past, "What good is acceleration if you never go faster?" Having the same Hubble-Lemaitre expansion rate for then and today would be far more problematic than the rates found.

But, to me, "explaining" an observation with an "explanation" that is simply putting another name on something that nobody understands is not an explanation at all.
Perhaps it's more a suppositional explanation.
 
Helio, you seem to have misinterpreted my comment about their just assuming that they will solve "the problem" with "early dark energy".

I think we can agree that messing with dark energy assumptions can "explain" the apparent acceleration in the "Hubble tension".

But, the "problem" I was referring to that has not been solved, but is assumed to be solvable with "early dark energy", is the "early formation of large galaxies in the infant universe", The article explicitly says "It is unclear just how early dark energy could have led to the early formation of large galaxies in the infant universe - yet" and then goes on to say "the fact that this model could kill two cosmic birds with one stone means the team thinks it's worth pursuing."

So, it is only an assumption that this model can explain "the early formation of large galaxies in the infant universe".

But the title of this article is "How dark energy could relieve 'Hubble tension' and galaxy headaches" [emphasis added].

And it does not actually tell us "how". Or even claim that anybody has figured out "how".
 
Helio, you seem to have misinterpreted my comment about their just assuming that they will solve "the problem" with "early dark energy".
IMO, DE does solve the tension but it's seems so obvious, that, as I said, the real tension would be if the expansion rates never changed. Given the likelihood that DE is a real phenomena, then why wouldn't there be a difference? Acceleration always increases velocity.

So, for me it is an obvious solution. But to put a bump in DE at 2k years seems very odd.

But to your point, they don't seem to present how their ideas would help form galaxies a little earlier than expected.

So, it is only an assumption that this model can explain "the early formation of large galaxies in the infant universe".
Right. I don't see why a little extra DE in the recipe is needed to cause quicker galaxy formation. It would seem to have more of an opposite effect.
 

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