DESI Survey Hints Dark Energy Weakened After 9 Billion Years
Updated
Updated · spacedaily.com · Jul 17
DESI Survey Hints Dark Energy Weakened After 9 Billion Years
3 articles · Updated · spacedaily.com · Jul 17
Summary
DESI’s 2025 analysis of 13.1 million galaxies suggests dark energy strengthened through the universe’s first 9 billion years, then began weakening about 4 to 5 billion years ago.
The result comes from tracing cosmic expansion with a fixed galaxy-separation “ruler,” but the changing-dark-energy signal appears only when DESI data are combined with cosmic microwave background and supernova measurements.
Combined analyses favor evolving dark energy at roughly 2.8 to 4.2 sigma, below physics’ 5-sigma discovery threshold, and the strength of the signal shifts with different supernova calibrations.
If confirmed, the finding would challenge the cosmological constant at the core of standard cosmology and reopen questions about whether cosmic expansion will accelerate forever or eventually slow.
Dark energy weakening or strengthening? How will new 2027 data finally settle the universe’s ultimate fate?
Is dark energy a cosmic illusion? New math suggests the universe can accelerate without this mysterious force.
With dueling studies clashing, is our entire standard model of cosmology now on the verge of collapse?
DESI’s 0.52% Precision Reveals Strongest Evidence Yet for Evolving Dark Energy, Challenging the Standard Cosmological Model
Overview
In March 2025, the DESI collaboration announced the strongest evidence yet that dark energy evolves over time. By building a detailed 3D map of the Universe, DESI tracks how matter is distributed and uses ancient Baryon Acoustic Oscillation patterns as a 'standard ruler.' This allows researchers to precisely measure the Universe’s expansion at different distances and directly observe changes in dark energy’s strength across cosmic history. These findings challenge the idea that dark energy is constant, opening new directions for understanding the Universe’s evolution and its mysterious accelerated expansion.