No, the Universe is not expanding at an accelerated rate, say physicists

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.

Earlier this year, NASA and ESA scientists found that the Universe could be expanding around 8% faster than originally thought.
By all accounts, the discovery was a solid one (Nobel Prize solid) but it posed a very difficult question - if the collective gravity from all the matter expelled into the Universe by the Big Bang has been slowing everything down, how can it be accelerating?

Since scientists first proposed dark energy, no one's gotten any closer to figuring out what it could actually be.
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.

Instead of finding evidence to support the accelerated expansion of the Universe, Sarkar and his team say it looks like the Universe is expanding at a constant rate. If that's truly the case, it means we don't need dark energy to explain it.Source & further reading:http://www.sciencealert.com/no-the-universe-is-not-expanding-at-an-accelerated-rate-say-physicists?perpetual=yes&limitstart=1

Paper:http://www.nature.com/articles/srep35596