Final Data from Atacama Telescope Challenges Cosmology Models

The final data released from the Atacama Cosmology Telescope, known as ACT, has significant implications for cosmological models, particularly regarding the Hubble tension. According to Live Science, the ACT's findings matched previous results from the Planck satellite, confirming a discrepancy in the universe's expansion rate as measured by early-universe probes compared to nearby measurements.

ACT tested around 30 extended cosmological models proposed to explain the Hubble tension, and all of them failed, suggesting that existing theories about the universe's expansion may need to be reevaluated.

This comprehensive dataset was published in November 2022 in the Journal of Cosmology and Astroparticle Physics, marking the end of a multi-decade mission designed to study the cosmic microwave background, or CMB, which offers insights into the early universe.

The ACT's high-resolution observations of the CMB's polarization could help refine measurements and potentially reshape our understanding of dark matter and dark energy. Furthermore, the data supports the notion that the universe is expanding at a slower rate than previously estimated, thus deepening the mystery surrounding the Hubble tension, which remains one of the greatest unsolved problems in modern cosmology.