For years physicists have tried to explain observations that the universe's expansion is speeding up in all directions with the concept of "dark energy".
Dark energy is a proposed form of energy that affects the universe on the largest scales and drives galaxies, stars and planets apart.
Now a team of New Zealand physicists led by UC Professor David Wiltshire analysed light curves from the Pantheon+ supernovae to show the universe was expanding in a "lumpier" way.
The new study - published in the Monthly Notices of the Royal Astronomical Society - shows the idea of "dark energy" is not needed at all.
Instead, the team proposed a different model - called timescape cosmology - to understand the evolution of the universe.
The scientists said the findings - together with new data - implied "profound consequences" for cosmology and astrophysics and may help resolve the universe's biggest mystery within five years.
On the UC website, Wiltshire says dark energy "may in fact be a misidentification of 'quasi-local gravitational energy', an aspect of Einstein’s theory that we have yet to fully understand".
"My team and I are testing its properties. In future we aim to more deeply understand the nature of gravitational energy by rigorously construct a modified statistical geometry for the universe.
"The aim is to understand 'dark energy' and possibly also 'dark matter' as a modified geometrical theory of gravity rather than new exotic 'stuff'."
The research was supported by the Marsden Fund, which earlier this year announced changes to its terms of reference that have been roundly criticised by the science community.
