A team of physicists and astronomers at the University of Canterbury in Christchurch, New Zealand, has challenged the long-held theory of dark energy, which is thought to drive the accelerating expansion of the universe. According to their analysis published in the journal Monthly Notices of the Royal Astronomical Society Letters, the cosmos may not be expanding uniformly in all directions as previously assumed.
The researchers used improved analysis of supernovae light curves to show that the universe’s expansion is more varied and “lumpy” than initially thought. This new evidence supports the “timescape” model of cosmic expansion, which suggests that differences in stretching light are due to variations in time and distance calibration rather than dark energy.
The timescape model takes into account the effect of gravity on time, which slows it down near massive objects like galaxies. This means that clocks in distant galaxy clusters would be slower than those at higher cosmic voids, leading to more expansion space over billions of years. According to Professor David Wiltshire, who led the study, this resolves the issue of dark energy as a misidentification of variations in the kinetic energy of expansion.
The new findings provide “very strong evidence” for the timescape model and may resolve some key questions about cosmic expansion. Further observations from satellites like Euclid and Nancy Grace Roman Space Telescope are needed to confirm the results, but the researchers believe that by the end of the decade, the universe’s biggest mystery could be settled.
The challenge to dark energy theory comes as new data from the Cosmic Microwave Background and Dark Energy Spectroscopic Instrument have raised questions about the standard Lambda Cold Dark Matter model. The findings highlight the need for more accurate cosmic expansion laws that can account for complex structures in the universe.
Source: https://phys.org/news/2024-12-dark-energy-doesnt-lumpy-universe.html