[Continuation] Why James Webb Telescope rewrites/doesn't the laws of Physics/Redshifts (2)

[catsmate]

You can, of course convert the units of the Hubble parameter into any units which have dimensions of inverse time. For example furlongs per fortnight per micron. But the convention is to quote it in units of km s^-1 Mpc^-1 because it is expressing an expansion speed per unit distance.

Hertz or baud perhaps?

 

[hecd2]

Hertz or baud perhaps?

If you like...about 2 attoHz.

 

[Mike Helland]

We know.

Between WDClinger's fabrication* to hecd's contradictions**, and your taking things out of context, it felt best to step away.

WDClinger: He's been claiming H times distance is redshift

hecd2: The scale factor is dimensionless so H has dimensions and units of s^-1 as defined.

also hecd2: Mike is confusing dimensions with units. The dimensions of the Hubble parameter is inverse time. The units of the Hubble parameter are km s^-1 Mpc^-1 - speed per unit distance.

What I've read since then also casts doubts on your coordinate system claims.


http://www.bourbaphy.fr/moschella.pdf

The de Sitter geometry finds its most important physical applications in cosmology. In cosmology one usually “breaks” the general relativistic covariance and singles out a special coordinate system: there is a natural choice of “cosmic time” that makes the universe appear spatially homo-geneous and isotropic at large scales. This property is mathematically encoded in the Friedmann-Robertson-Walker line element:

http://latex.codecogs.com/gif.latex?ds^2 = dt^2 − a(t)^2dl^2​

The spatial distance dl2 describes the geometry of a homogeneous and isotropic space manifold: either S3, R3 or H3.

In this respect the de Sitter geometry is rather special: due to the maximal symmetry and the topology of the de Sitter manifold, all three possible FRW cosmologies can be realized on de Sitter by suitable choices of the cosmic time coordinate (see Figure 6).

(click thumbnail to read the caption)

Ok. Well about this "cosmic time". Do we need it?

https://en.wikipedia.org/wiki/Cosmic_time

Why can't you just use the measured coordinates of the observer? Since they exhibit time dilation, you can remove the effects of time dilation with the equation:

http://latex.codecogs.com/gif.latex?\tau = \frac{1}{H_0} (e^{H_0t} - 1)​

This doesn't need any kind of "cosmic time", but I think the http://latex.codecogs.com/gif.latex?\tau could be regarded as some kind of "conformal time" because it makes all the right angles and straight lines and stuff? I dunno.

Ok, as for choosing time coordinates, the "de Sitter tour" goes on:

Another possible choice of time is http://latex.codecogs.com/gif.latex?x_0 + x_4 (see Figure 8). The time parameter is introduced by the relation http://latex.codecogs.com/gif.latex?x_0 + x_4 = = Re^{\frac{t}{R}}; with this coordinate only one half of the manifold is covered.

...

It is interesting to note that the first coordinate system used by de Sitter himself was a static coordinate system with closed spatial sections. De Sitter was following Einstein’s cosmological idea of a static closed universe, the idea that led to the introduction of the cosmological term in Einstein’s equations.

(click thumbnail to read the caption)

A couple other sources say similar things:

As originally shown by de Sitter (1917, MNRAS, 78, 2), there are actually two effects at work in his metric. The first effect is that time seems to run slower at large r, causing distant objects to appear redshifted. However, this effect is only meaningful for objects at fixed coordinate distance, which are not on geodesics, and more importantly, the relation is quadratic between velocity and distance.

https://astro.uchicago.edu/~kent/fnal/effect.html

This is a static universe (not just 'more or less'). We see that at r=α the metric has a cosmological horizon. The region r<α

contains the operationally meaningful portion of the de Sitter space, which can be probed by a single observer located at origin.

The factor at dt² could indeed be interpreted as defining position-dependent time dilation. An object held at a fixed distance from the observer appears redshifted. If released, such object will be accelerating toward the horizon, so your description is accurate in this respect.

https://physics.stackexchange.com/q...bble-redshift-be-interpreted-as-time-dilation

And here's de Sitter's 1917 paper:

https://watermark.silverchair.com/m...YGVsI-3TFN1DQp8WGO7l9nKbLMlMk96TBjdXyz4RsGetm

So I guess as far as the map territory stuff goes, choosing how to make your time coordinate seems like a normal thing to do.

And de Sitter's original version, seems to give a time dilated past, when the appropriate part of the manifold is covered, which in this case should be less than or equal to zero but greater than -1. This represents the present and the past.

 

[Mike Helland]

Saw this today:

"Theoretical and observational challenges to standard cosmology such as the cosmological constant problem and tensions between cosmological model parameters inferred from different observations motivate the development and search of new physics. A less radical approach to venturing beyond the standard model is the simple mathematical reformulation of our theoretical frameworks underlying it. While leaving physical measurements unaffected, this can offer a reinterpretation and even solutions of these problems. In this spirit, metric transformations are performed here that cast our Universe into different geometries. Of particular interest thereby is the formulation of cosmology in Minkowski space. Rather than an expansion of space, spatial curvature, and small-scale inhomogeneities and anisotropies, this frame exhibits a variation of mass, length and time scales across spacetime. Alternatively, this may be interpreted as an evolution of fundamental constants. As applications of this reframed cosmological picture, the naturalness of the cosmological constant is reinspected and promising candidates of geometric origin are explored for dark matter, dark energy, inflation and baryogenesis. An immediate observation thereby is the apparent absence of the cosmological constant problem in the Minkowski frame. The formalism is also applied to identify new observable signatures of conformal inhomogeneities, which have been proposed as simultaneous solution of the observational tensions in the Hubble constant, the amplitude of matter fluctuations, and the gravitational lensing amplitude of cosmic microwave background anisotropies. These are found to enhance redshifts to distant galaxy clusters and introduce a mass bias with cluster masses inferred from gravitational lensing exceeding those inferred kinematically or dynamically."

https://iopscience.iop.org/article/10.1088/1361-6382/acdb41

Found it from this article:

https://www.livescience.com/physics...ld-be-a-mirage-new-theoretical-study-suggests

 

[Darat]

And how does that relate to your ideas and claims in this thread?

 

[Mike Helland]

And how does that relate to your ideas and claims in this thread?

"Theoretical and observational challenges to standard cosmology such as the cosmological constant problem and tensions between cosmological model parameters inferred from different observations motivate the development and search of new physics. ... Rather than an expansion of space, spatial curvature, and small-scale inhomogeneities and anisotropies, this frame exhibits a variation of mass, length and time scales across spacetime."

Their approach is a bit different:

Importantly, as shown in the following, despite the static geometry of the Universe in Sec. 3.1.1, cosmological observations are still redshifted. However, rather than due to the expanding space, redshift is caused here by evolving particle masses [21, 22] (also see Ref. [23]). Thus, a photon emitted in the past as the result of some atomic line transition will be redshifted with respect to the measured emission of the same transition in our local, present laboratories. Photons still follow null geodesics in the conformally transformed frame [22] and our detectors measure them at their emission frequencies.

 

[Darat]

That doesn’t provide an answer.

 

[Mike Helland]

That doesn’t provide an answer.

Really?

They say the past is heavier.

Or lighter.

Can't really tell.

But they also do it in Minkowski spacetime.

Either way, they're looking for an alternative explanation of redshift to the expansion of space, because the current theory has too many problems.

The problem that jumps out at me with their explanation is the time dilation of supernovae seems to be missing. Unless that's supposed to be explained by the different masses of particles at different epochs. They don't mention time dilation by name at all in the paper.

 

[Ziggurat]

Either way, they're looking for an alternative explanation of redshift to the expansion of space, because the current theory has too many problems.

And? What's that got to do with your alternative explanation? Theirs is different than yours.

 

[Mike Helland]

And? What's that got to do with your alternative explanation? Theirs is different than yours.

Theirs is a "mass dilated" past.

Mine is a time dilated past.

Both are proposed as alternatives to the expansion of space.

The issues facing the standard model of cosmology are making people seriously consider alternatives to the expansion interpretation of redshifts. That's been denied up and down here, but that's what's up.

It seems to me that the kg is likely now related to some kind of time measurement. At least that was the plan the last I heard. So a time dilated past might also imply what they're talking about.

In any case, my model is better (just ask me, I'll tell ya!).

Mine points out that a time dilated electromagnetic wave is a redshifted wave, so it reduces the time dilation of supernovae and redshifts to a single phenomenon.

That idea came about through a discussion with you.

Other ideas have been brought up. And I've also been posting articles for and against rewriting the physics of redshifts based on new observations, mainly JWST stuff.

I think you're somehow trying to paint it as "wrong" to post about physicists dealing with the new observational reality by exploring non-expanding models.

Frankly, if I were to have posted this in a separate thread, you'd think that was "wrong" too. No?

 

[Ziggurat]

Theirs is a "mass dilated" past.

Mine is a time dilated past.

And? These aren't equivalent.

Both are proposed as alternatives to the expansion of space.

Firing people out of cannons in a giant shell was a proposed method of getting people to the moon. It's not on par with rockets.

The issues facing the standard model of cosmology are making people seriously consider alternatives to the expansion interpretation of redshifts. That's been denied up and down here, but that's what's up.

No, it hasn't been denied. What's been denied is that any of these proposed alternatives are better than the current model. And so far they aren't.

Maybe one of them will be at some point, and it's worthwhile for actual physicists who know what they're doing to examine such possibilities and work through them to see what's possible. And that's happening, and nobody here objects to it happening. But you don't know what you're doing, your alternative has already failed, you can't even comprehend its failures because you don't actually know enough physics or math to be able to evaluate what you're doing, and you're wasting everyone's time including your own.

In any case, my model is better (just ask me, I'll tell ya!).

No, it isn't. It really isn't.

I think you're somehow trying to paint it as "wrong" to post about physicists dealing with the new observational reality by exploring non-expanding models.

Not at all. Rather, these alternatives proposed by actual physicists don't validate your own nonsensical ramblings, which I know is the actual reason you're posting them.

Frankly, if I were to have posted this in a separate thread, you'd think that was "wrong" too. No?

Wrong to post it? Nope. The theory itself is probably wrong, because most proposed theories are wrong. That's always going to be the case, it's unavoidable.

It can still be worth examining alternative theories even if they're probably wrong because 1) occasionally they will turn out to be right, and 2) you can still learn in the process of figuring out why the wrong ones are wrong. But your theory is so bad that we already know it's wrong, and it's so obviously wrong that nobody is learning anything from it. Even you would learn more if you simply studied physics from the start, but that's one thing you refuse to do.

 

[hecd2]

Between WDClinger's fabrication* to hecd's contradictions**, and your taking things out of context, it felt best to step away.

WDClinger: He's been claiming H times distance is redshift

hecd2: The scale factor is dimensionless so H has dimensions and units of s^-1 as defined.

also hecd2: Mike is confusing dimensions with units. The dimensions of the Hubble parameter is inverse time. The units of the Hubble parameter are km s^-1 Mpc^-1 - speed per unit distance.

There was no contradiction. You have been claiming that the dimensions and the units of the Hubble parameter are definitively s^-1. That’s not so. The dimensions of the Hubble parameter are always T^-1 but the units can be anything you like provided those units also have dimensions of T^-1. If you change the units then the value will also change.

My first statement was in the context of the definition which relates H to the scale factor - H equals the first time derivative of the scale factor divided by the scale factor, and since the scale factor is dimensionless then H, in this context has dimensions of T^-1 and units of s^-1 in SI units. In this H = about 2.3 attohertz or 2.3 etaseconds ^-1 (something I mentioned in the post immediately prior to yours.]

However in cosmology, H is taken to be an expansion rate per unit distance and is stated in km s^-1 Mpc^-1, and has a value of about 70. Measurements of H do depend on the fact that it represents an expansion rate per unit distance.

So, no contradiction, just your general confusion about everything.

 

[Mike Helland]

There was no contradiction.

Riiiight.


ETA And this is circular:

"Measurements of H do depend on the fact that it represents an expansion rate per unit distance."

The expansion rate is the expansion rate per distance?

You seem to be unwilling or incapable of acknowledging a simple error.

 

[hecd2]

Riiiight.

Passive aggression, ignorance and arrogance all rolled up in an unsavoury package. The fact that you think there is a contradiction just shows that you haven’t the first clue about any of this stuff.

 

[Mike Helland]

Passive aggression, ignorance and arrogance all rolled up in an unsavoury package. The fact that you think there is a contradiction just shows that you haven’t the first clue about any of this stuff.

hecd2: The scale factor is dimensionless so H has dimensions and units of s-1 as defined.

hecd2: Mike is confusing dimensions with units. The dimensions of the Hubble parameter is inverse time. The units of the Hubble parameter are km s-1 Mpc-1 - speed per unit distance.

Anyone can see it.

 

[hecd2]

Riiiight.


ETA And this is circular:

No it’s not

The expansion rate is the expansion rate per distance?

Yes.

You seem to be unwilling or incapable of acknowledging a simple error.

No that’s you.

 

[hecd2]

hecd2: The scale factor is dimensionless so H has dimensions and units of s-1 as defined.

hecd2: Mike is confusing dimensions with units. The dimensions of the Hubble parameter is inverse time. The units of the Hubble parameter are km s-1 Mpc-1 - speed per unit distance.

Anyone can see it.

Yes. Anyone who has a clue about any of this stuff will see that those two statements are made in different contexts and are not contradictory. As I explained and you were unwilling to or incapable of understanding.

 

[Mike Helland]

No it’s not

Have a little dignity. The three of you now find it more important to find some way to disagree with me than to maintain your credibility.

 

[Mike Helland]

Yes. Anyone who has a clue about any of this stuff will see that those two statements are made in different contexts and are not contradictory. As I explained and you were unwilling to or incapable of understanding.

Here's the context:

I said they were in units A, you said No, they are in units B.

I said they were in units B, you said No, they are in units A.

You find it more important to stick to the argument that I'm always wrong, than actually being right. I'm moving past this.

 

[Ziggurat]

hecd2: The scale factor is dimensionless so H has dimensions and units of s-1 as defined.

s^-1 is a unit, not a dimension. It has a dimension, but it is not a dimension.

hecd2: Mike is confusing dimensions with units.

That is correct. Time is a dimension, it is not a unit. A second is a unit of time, it has dimensions of time, but it is not a dimension, it is a unit. A year is a unit of time as well. Years and seconds have the same dimension but are different units. H has dimensions of inverse time. It can have any units that satisfy that dimension, including inverse seconds, various units of velocity divided by distance, etc.

Anyone can see it.

Indeed we can. But for some reason, you cannot.

 

[hecd2]

s^-1 is a unit, not a dimension. It has a dimension, but it is not a dimension.

.

That’s right. My original statement was sloppy but I corrected it seven or eight posts above.

 

[hecd2]

Have a little dignity. The three of you now find it more important to find some way to disagree with me than to maintain your credibility.

We disagree with you because you know absolutely no physics or maths and every statement you make is wrong. Every one.

Expansion rate (in km/s) per unit distance (in Mpc) is not circular and is exactly how the Hubble constant is understood. Surely you know this.

 

[theprestige]

Have a little dignity. The three of you now find it more important to find some way to disagree with me than to maintain your credibility.

The easiest way for them to undermine their credibility as rational thinkers would be to start agreeing with you.

 

[Mike Helland]

What's been denied is that any of these proposed alternatives are better than the current model. And so far they aren't.

What objective criteria is used to determine that?

 

[Ziggurat]

What objective criteria is used to determine that?

How well they fit the data. All the data. Which includes a lot more than red shifts.

As a very easy example we've already covered at length, none of your ideas have ever fit the CMB at all.

 

[SteveAitch]

As a very easy example we've already covered at length, none of your ideas have ever fit the CMB at all.

Maybe Mike's working on the Hitchhiker's Guide principle:

"The Guide is definitive. Reality is frequently inaccurate."

 

[Mike Helland]

How well they fit the data. All the data. Which includes a lot more than red shifts.

As a very easy example we've already covered at length, none of your ideas have ever fit the CMB at all.

Objectively, the standard model doesn't fit all the evidence either.

The CMB was predicted to be a consequence of an expanding universe.

Besides the original prediction, is there any other piece of evidence that ties the CMB to an expanding universe?

If one made a theory that tied an earthquake in Turkey 120 years ago to the US economy in the 1980's, it would probably be the best the theory there is that fits both pieces of evidence.

But what if the two pieces of data aren't related? That means the best theory for the data, is still a bad theory.

So, has there ever been any independent confirmation that the CMB is related to the redshifts?

Were LCDM to have successfully predicted the expansion rate we measure, I suppose that would count. But obviously, it isn't successful. That's just one of its significant flaws:

Eight Significant Shortcomings of the Standard Model of Cosmology

Problem 1: The observed spectral amplitude of the CMB is below the predicted value

Problem 2: No satisfactory explanation of the quantum-to-classical transition between inflation and the hot Big Bang

Problem 3: Why is the Higgs vacuum expectation value the same everywhere?

Problem 4: Lithium fails to match the predictions of Big Bang nucleosynthesis

Problem 5: The low-entropy configuration as required by ΛCDM is extremely unlikely

Problem 6: Observations show fully-formed galaxies while ΛCDM predicts stars only for the same epoch

Problem 7: Discrepancy between independent measurements of the Hubble constant

Problem 8: ΛCDM is inconsistent with Einstein’s equivalence principle

https://new-ground.com/en/articles/...dard-model-of-cosmology/new-ground.2023.77033

Problem's 1, 5, and 7 due to the CMB.

The CMB also has three significant anomalies: a cold spot, asymmetric hemisphere temperatures, and the correlation with our solar system, aka, axis of evil.

This list doesn't include the S8 tension, also due to the CMB data.

How can we be sure the microwave radiation in question is even cosmological in nature?

It's original predicted temperature isn't right, it's the source of several major "cracks" in the standard model of cosmology, and it contains anomalies.

At what point do we permit some skepticism as to origin?

 

[Ziggurat]

Objectively, the standard model doesn't fit all the evidence either.

It fits the data better than any other model proposed so far. Yours isn't even in the running.

The CMB was predicted to be a consequence of an expanding universe.

Besides the original prediction, is there any other piece of evidence that ties the CMB to an expanding universe?

What the hell are you on about? The theory predicts a CMB. We measure a CMB. You don't need some other piece of evidence.

If one made a theory that tied an earthquake in Turkey 120 years ago to the US economy in the 1980's, it would probably be the best the theory there is that fits both pieces of evidence.

Well, no. Plate tectonic theory says nothing about economics, and economic theories say nothing about earthquakes. You're correct that it's OK to have two different theories to cover two unconnected things.

But here's the fundamental problem which you can't grasp because you don't understand physics. Alternative cosmologies predict that there shouldn't be a CMB, or if there is one it shouldn't be a perfect black body spectrum. They aren't actually silent on the topic, they're wrong.

How can we be sure the microwave radiation in question is even cosmological in nature?

Because it's behind everything else we see. We've been over this before.

It's original predicted temperature isn't right

Not relevant.

At what point do we permit some skepticism as to origin?

You're permitted all the skepticism you want. You're not permitted to substitute an objectively worse theory on the basis of that skepticism.

 

[Mike Helland]

It fits the data better than any other model proposed so far.

That's the prevailing belief.

It kind of looks like de Sitter's 1917 model with closed static spatial coordinates might have been a better fit all along.

What the hell are you on about? The theory predicts a CMB. We measure a CMB. You don't need some other piece of evidence.

How scientific.

You're permitted all the skepticism you want. You're not permitted to substitute an objectively worse theory on the basis of that skepticism.

If the time dilated past was a worse fit for the data, you'd have a point.

Right now your argument, or rather than prevailing argument, which is fair and reasonable, by the way, hinges on the assumption that the CMB data and the redshift data are actually related.

We assume they are.

How can we know that's true beyond the shadow the of a doubt?

 

[Ziggurat]

That's the prevailing belief.

It's not a belief. It's objectively true. The fit to data isn't perfect, but it's better than any alternative.

It kind of looks like de Sitter's 1917 model with closed static spatial coordinates might have been a better fit all along.

That model has the glaring flaw of not having any matter in it. So... a very bad fit to the data.

If the time dilated past was a worse fit for the data, you'd have a point.

It is a worse fit for the data. Your time dilated past theory has no CMB. If your theory was right, the CMB should not exist.

Right now your argument, or rather than prevailing argument, which is fair and reasonable, by the way, hinges on the assumption that the CMB data and the redshift data are actually related. How can we know that's true beyond the shadow the of a doubt?

We can't know that for 100% sure. What we do know is that the CMB exists. The standard model accounts for its existence. None of the non-expansion alternatives do in any way, shape, or form. Under all the non-expansion alternatives including yours, the CMB should not exist. But it does.

 

[Mike Helland]

It is a worse fit for the data. Your time dilated past theory has no CMB. If your theory was right, the CMB should not exist.

The microwave radiation exists.

Is it the signature of an ancient fireball?

It could just be waste heat of the solar system or something much more mundane.

One idea describes the beginning and evolution of the universe itself.

The other is kind of boring. But it too was predicted (and more accurately temperature wise).

In any case, we seem to agree that the only thing connecting the "temperature of space" to redshifts is Gamow's prediction of it.

We know that if we place something out in space, the CMB will keep it from falling to a temperature of less than 2.7 K. So whether it is cosmic background, or something else, "temperature of space" seems to be a neutral enough description of it.

We can't know that for 100% sure.

You'd think someone would have proposed and confirmed another line of evidence connecting the two by now.

 

[steenkh]

The microwave radiation exists.

Is it the signature of an ancient fireball?

It could just be waste heat of the solar system or something much more mundane.

Nope. It has a blackbody spectrum, thus no fireball or waste heat.

 

[hecd2]

The microwave radiation exists.

Is it the signature of an ancient fireball?

It could just be waste heat of the solar system or something much more mundane.

One idea describes the beginning and evolution of the universe itself.

The other is kind of boring. But it too was predicted (and more accurately temperature wise).

But it fails utterly and miserably to predict the actual characteristics of the CMB, its spectrum and its anisotropies.

At this stage you are just parroting know-nothing crackpots. No-one has ever been able to make a convincing case for the origin of the CMB as waste heat or anything else “mundane”. And you won’t be able to either. As I said, every statement you make is wrong, every single one.

 

[Mike Helland]

Nope. It has a blackbody spectrum, thus no fireball or waste heat.

The CMB's standard interpretation is as the remnants of a primordial fireball.

 

[steenkh]

The CMB's standard interpretation is as the remnants of a primordial fireball.

Not the last time I checked. You haven’t really tried to understand what is meant by the Big Bang theory, have you?

Hint: the BB is not an explosion.

 

[Ziggurat]

It could just be waste heat of the solar system or something much more mundane.

No, it could not. The fact that you believe it could is yet another indication of your profound ignorance. That you still believe this even after it's been explained to you multiple times indicates that this ignorance is willful.

One idea describes the beginning and evolution of the universe itself.

The other is kind of boring. But it too was predicted (and more accurately temperature wise).

The temperature isn't the significant part of the CMB.

 

[hecd2]

The CMB's standard interpretation is as the remnants of a primordial fireball.

An extremely peculiar fireball, being the same in every direction we look, so all around us, arising from a source at a single temperature described by the Saha equation and lacking any emission or absorption spectral lines. So, not a fireball at all in the conventional sense.

 

[Mike Helland]

No-one has ever been able to make a convincing case for the origin of the CMB as waste heat or anything else “mundane”. And you won’t be able to either.

In de Sitter's closed coordinates there is a cosmological horizon.

(ETA: In other contexts, cosmological horizons have a temperature. such as: )

https://physics.stackexchange.com/q...-to-the-cosmological-horizon-during-inflation

During inflation, the de Sitter space has a cosmological event horizon. This horizon exists because farther than the horizon distance the expansion carries light away from the observer faster than the light can travel. This cosmological horizon emits Hawking radiation.

It seems there is a "de Sitter temperature" (or "Gibbons-Hawking temperature"?), is "T=H/2pi".

Not sure how the units work on that... but a time dilated past with a cosmological horizon seems to predict a temperature.

 

[Mike Helland]

Not the last time I checked. You haven’t really tried to understand what is meant by the Big Bang theory, have you?

Hint: the BB is not an explosion.

The CMB is leftover radiation from when the universe was filled was hot plasma. Specifically from when it cooled to certain a point.

"In the Big Bang cosmological models, during the earliest periods, the universe was filled with an opaque fog of dense, hot plasma of sub-atomic particles. As the universe expanded, this plasma cooled to the point where protons and electrons combined to form neutral atoms of mostly hydrogen. Unlike the plasma, these atoms could not scatter thermal radiation by Thomson scattering, and so the universe became transparent.[4] Known as the recombination epoch, this decoupling event released photons to travel freely through space – sometimes referred to as relic radiation."

https://en.wikipedia.org/wiki/Cosmic_microwave_background

Gamow called it a primordial fireball, if I recall correctly. Whatever you want to call it, that's fine with me.

 

[Mike Helland]

The temperature isn't the significant part of the CMB.

Well, if we say that the light from beyond c/H₀ can't reach us, that creates a cosmological horizon.

Would Hawking radiation happen there?

https://en.wikipedia.org/wiki/Hawking_radiation

"Hawking radiation is the theoretical thermal black body radiation released outside a black hole's event horizon."

That would have the necessary spectrum.