http://www.sciencealert.com/no-the-universe-is-not-expanding-at-an-accelerated-rate-say-physicists
Interesting.
Back in 2011, three astronomers were awarded the Nobel Prize in Physics for their discovery that the Universe wasn’t just expanding - it was expanding at an accelerating rate.
The discovery led to the widespread acceptance of the idea that our Universe is dominated by a mysterious force called dark energy, and altered the standard model of cosmology forever. But now physicists say this discovery might have been false, and they have a much larger dataset to back them up....
...But now an international team of physicists from institutions say don't worry about it, because it probably doesn't even exist, and they've got a much bigger database of Type 1a supernovae to back them up.
By applying a different analytical model to the 740 Type Ia supernovae that have been identified so far, the team says they've been able to account for the subtle differences between them like never before.
They say the statistical techniques used by the original team were too simplistic, and were based on a model devised in the 1930s, which can't reliability be applied to the growing supernova dataset.
They also mention that the cosmic microwave background isn't directly affected by dark matter, so only serves as an "indirect" type of evidence.
"We analysed the latest catalogue of 740 Type Ia supernovae - over 10 times bigger than the original samples on which the discovery claim was based - and found that the evidence for accelerated expansion is, at most, what physicists call '3 sigma'," reports lead researcher, Subir Sarkar, from the University of Oxford....
Interesting.