Universe not dominated by dark energy

The Universe is expanding at a constant rate, and is not dominated by “dark energy”, according to a new study led by an Indian-origin researcher, which casts doubt on the Nobel Prize winning discovery stating that the cosmos is undergoing accelerating expansion.

Five years ago, the Nobel Prize in Physics was awarded to three astronomers for their discovery that the Universe is expanding at an accelerating pace. Their conclusions were based on analysis of Type Ia supernovae — the spectacular thermonuclear explosion of dying stars — picked up by the Hubble space telescope and large ground-based telescopes.

It led to the widespread acceptance of the idea that the Universe is dominated by a mysterious substance named “dark energy” that drives this accelerating expansion.

Scientists led by Subir Sarkar of Oxford University in the UK have cast doubt on this standard cosmological concept. Making use of a vastly increased data set, a catalogue of 740 Type Ia supernovae, more than ten times the original sample size — the researchers have found that the evidence for acceleration may be flimsier than previously thought, with the data being consistent with a constant rate of expansion.

“The discovery of the accelerating expansion of the Universe won the Nobel Prize, the Gruber Cosmology Prize, and the Breakthrough Prize in Fundamental Physics,” said Sarkar, who also holds a position at the Niels Bohr Institute in Copenhagen.