New research challenges the long-held idea that dark energy is driving the accelerating expansion of the universe. According to scientists, this mysterious energy source might be an artifact of our current understanding of space and time.
The Lambda Cold Dark Matter (ΛCDM) model, which has been the standard cosmological model for nearly a quarter century, relies on the existence of dark energy to explain the observed acceleration in the expansion rate of the universe. However, recent observations have sparked controversy.
Studies of the cosmic microwave background radiation, known as the afterglow of the Big Bang, have revealed an anomaly known as the Hubble tension, where the expansion rate of the early universe seems to be at odds with current measurements. Additionally, high-precision data from the Dark Energy Spectroscopic Instrument (DESI) suggest that dark energy is not a constant force, but rather evolves over time.
These findings are difficult to reconcile using the simplified 100-year-old cosmic expansion law known as Friedmann’s equation, which assumes uniform expansion. However, researchers believe that this model may not accurately capture the complex structure of the universe, with galaxy clusters and voids that affect the expansion rate.
The new evidence supports the timescape model of cosmic expansion, which suggests that dark energy is an illusion created by our current understanding of time and distance. According to this model, differences in stretching light are due to variations in gravitational time dilation, rather than an accelerating universe.
This breakthrough could resolve some of the key questions surrounding the quirks of the expanding cosmos, with one scientist predicting that new data from the ESA’s Euclid satellite could answer these questions by the end of the decade. With 1,000 independent supernovae observations, the researchers hope to distinguish between the Friedmann equation and the timescape alternative.
Source: https://www.sci.news/astronomy/dark-energy-13531.html