It turns out that there are a few astronomers who believe that the Universe is not expanding at an accelerating pace and that there is no dark energy that is facilitating this accelerated expansion.
Researchers at Oxford University’s Department of Physics have cast doubt on the Noble Prize winning discovery that our Universe is expanding rapidly stating that one of the key pillars of the standard cosmological model is rather shaky. Researchers agree that their results can’t be etched in stone, but they have managed to demonstrate that investigation is needed into this area and that the previous beliefs need reexamination.
Back in 1990 a team of astronomers put forward the claims that Universe is expanding at an accelerated pace based on observations of Type Ia supernovae – the spectacular thermonuclear explosion of dying stars – that was picked up by the Hubble space telescope and large ground-based telescopes. Nobel Prize in Physics for 2011 was awarded to three astronomers for their discovery. This particular study also led physicists to initiate massive studies in dark energy – a mysterious substance that they believed is causing this accelerating expansion of the Universe.
However, a team led by Professor Subir Sarkar of Oxford University has published a paper in the Nature journal Scientific Reports wherein they have challenged this expansion theory. For their study researchers used a vast data set that includes a catalogue of 740 Type Ia supernovae – more than ten times the original sample size – to find that there is flimsy evidence of accelerated expansion of Universe and instead they say that the Universe is expanding at a constant rate.
Back when the original study that proposed accelerated expansion of Universe was carried out there was a limited data set to analyse. However, now the data set has expanded and this will enable a much more rigorous and detailed statistical analyses and that’s what the scientists at Oxford did.
Researchers analysed the latest catalogue of 740 Type Ia supernovae and found that the evidence for accelerated expansion is, at most, what physicists call “3 sigma”. This is far short of the “5 sigma” standard required to claim a discovery of fundamental significance.
The researchers hope that their study will motivate better analyses of cosmological data, as well as inspire theorists to investigate more nuanced cosmological models.