The expansion of the universe may not be acelerated

[kunok]

http://www.ox.ac.uk/news/science-blog/universe-expanding-accelerating-rate-–-or-it

They made an analisys of the latest cataloge of 740 supernova Ia and it only gives a 3 sigma signal.

It doesn't seem a strong indication tho, IIRC the supernovas aren't the most important proof of the aceleration.

Edited October 25, 2016 by kunok

[Mikki]

-'So it is quite possible that we are being misled and that the apparent manifestation of dark energy is a consequence of analysing the data in an oversimplified theoretical model – one that was in fact constructed in the 1930s, long before there was any real data. -

Einsteins foolery.  

[Steel]

8 hours ago, kunok said:

http://www.ox.ac.uk/news/science-blog/universe-expanding-accelerating-rate-–-or-it

They made an analisys of the latest cataloge of 740 supernova Ia and it only gives a 3 sigma signal.

It doesn't seem a strong indication tho, IIRC the supernovas aren't the most important proof of the aceleration.

I would say it's a fairly significant result. If this sort of thing can be applied and held true across past and future supernova measurements it could very well mean changing or superceding the ΛCDM model, which is not necessarily bad thing. At the end of the day this is a model that currently requires inflation (or any of your other your favorite, similar mechanisms) and possibly a quintessence mechanism (still debatable) added into it to explain many observational phenomena.

While this definitely does not disprove acceleration, it may mean that our cosmology needs to be a little more nuanced which may bring about some exciting changes. On the other hand it could be statistics playing its wonderful games with us.

Edited October 24, 2016 by Steel
Spelling, grammar, you name it: I got it wrong...

[Jovus]

Also, 3 sigma (while outside the 'standard' of 'proof') is still pretty likely.

Assuming the distribution is correct.

[K^2]

We are still talking about something which has odds of being wrong a little better than one in a thousand from this experiment alone. Other experiments, while having lower sigmas on their own, confirm this one. Which brings up the total into 4-5 sigma range for the theory.

Sure, it's still not certainty, but the headline of the article is in the same category as "Evolution hasn't been proven."

[YNM]

(pre-published) Papers :

Discussed work  : https://arxiv.org/pdf/1506.01354v3.pdf

Previous work (original, or so) : https://arxiv.org/pdf/astro-ph/9805201v1.pdf

Interesting to see two similar plots here :

I'm not sure, but it looks like their data would put more confidence in instead...

 

EDIT : It sounds like the paper is actually talking about a slightly differentiated version of ΛCDM (or rather, that it's not really that accurate). Which, of course, have been in the works since computing power increased, and has been well-known that it's not the best model ever possible so far. So no big changes IMHO.

They're not talking that the Universe isn't expanding, they're talking that it might not be due to Ω_Λ.

Edited October 25, 2016 by YNM