I Is There really a Hubble Tension?

[Arman777]

There has been a lot of Hubble Tension questions and I know its kind of boring ( maybe for some people) but this seems interesting.

I find this article

https://arxiv.org/pdf/1911.06456.pdf
It claims that

"The results are shown in Figure 1 which makes it evident that the derived value of $H_0$ varies by several $km s^{−1}Mpc^{−1}$ depending on which public SNe Ia catalogue is used. In particular the value obtained using the more recent Pantheon catalogue (Scolnic et al. 2018) is quite consistent with the CMB determination (Aghanim et al. 2018). A significant discrepancy cannot therefore be claimed "

Is this even possible ?

 

[Vanadium 50]

Is this even possible ?

Is what possible? That two different datasets give two different values? It's not only possible, it's a near certainty.

 

[kimbyd]

The claims in this paper were honestly the most likely outcome of this tension all along. I don't think there's yet enough evidence to say definitively that it was a red herring, but it's looking more and more likely.

 

[Arman777]

We have earlier reported that the redshifts of over 100 Type Ia supernovae (SNe Ia) which are in common between the SDSSII-SNLS3 Joint Lightcurve Analysis (JLA) catalogue (Betoule et al. 2014) and the subsequent Pantheon compilation (Scolnic et al. 2018) are discrepant

And then

Thus the systematic uncertainties that apparently still plague the distance ladder measurement of H0 undermine the significance of the discrepancy claimed by Riess et al. (2019).

Now the odd thing is that, the person who is working on correcting the discrepancies between two data sets (Scolnic), actually seems to be the writer (or contributor) of these articles.https://ui.adsabs.harvard.edu/abs/2016ApJ...826...56R/abstracthttps://iopscience.iop.org/article/10.3847/1538-4357/ab1422/pdfI mean, The guy who works on the discrepencies will somehow miss the whole point for 2 articles and not making any correction ...

I don't think we should trust every written article as well. Goes for all sides. Its like every week there's least 3 articles about Hubble tension.

 

[phyzguy]

One thing that you need to realize is that, especially for people writing articles for popular consumption, it's much more exciting to say, "There's a major discrepancy in our model of cosmology! We have to throw out everything we thought we knew and start over!" than it is to say, "After working for the last 10 years to measure the Hubble constant, we have reduced the error from 5% to 2%, and everything is in agreement with our standard model of cosmology."

 

[PAllen]

I just heard a talk by Adam Riess. He discussed his use of Pantheon. He still emphatically claims tension of 5 sigma between direct distance ladder Hubble (late universe) and CMB (early universe extrapolations).

 

[Arman777]

Is what possible? That two different datasets give two different values? It's not only possible, it's a near certainty.

I meant the Hubble Tension is being discussed in past 5 years( maybe more maybe less )and no one noticed this data difference ? Indeed in time our datas and their precision will get better.

 

[Arman777]

I just heard a talk by Adam Riess. He discussed his use of Pantheon. He still emphatically claims tension of 5 sigma between direct distance ladder Hubble (late universe) and CMB (early universe extrapolations).

So is he used the new data set or not ?

 

[PAllen]

So is used the new data set or not ?

Yes.

 

[kimbyd]

I just heard a talk by Adam Riess. He discussed his use of Pantheon. He still emphatically claims tension of 5 sigma between direct distance ladder Hubble (late universe) and CMB (early universe extrapolations).

It'll definitely be interesting to see how it pans out. More time and more data, I suppose.

No matter what, something interesting is going on.

 

[Vanadium 50]

The following just appeared on the arXiv: Calibration of the Tip Of The Red Giant Branch (TRGB).

This is a distance ladder that is completely independent from the Cepheid ladder. The results are in between the Cepheid-ladder measurements and CMB measurements (red):

I personally don't think either technique is "better" than the other. The fact that their widths are about the same indicates that the authors don't think so either. Indeed, the only measurement claiming to do substantially better than the others is Planck. If it weren't for that, we'd have a value of 71 or 72 +/- 3 and be OK with it.