Dark Energy: How a New Survey Changes the Picture ⚡ экспресс
Analysis of DESI DR2 data (a spectroscopic survey) combined with Type Ia supernovae and the cosmic microwave background has put the idea of an evolving dark energy to the test. Different models were tested, where dark energy density is described by parameters w₀ and wₐ. The trail of clues pointing to evolution was led mainly by LRG1-2 tracer galaxies, but the verdict remains fuzzy and statistically weak (significance 1.1–2.3 σ). Curiously, most models predict a 'phantom crossing' at a redshift of ~0.5 — as if dark energy switched gears halfway through. But it's still too early to claim a discovery.
For almost a hundred years, astronomers have known that galaxies are flying apart. But in the 1990s, observations of supernova explosions revealed: this is happening faster and faster. The cause was dubbed dark energy — an invisible force inflating space. The discovery earned the Nobel Prize for Солу Перлмуттеру, Адаму Риссу, and Брайану Шмидту. Since then, scientists have been trying to figure out whether this cosmic 'gas pedal' is constant.
The new DESI survey mapped millions of галактик and tracked their motion via imprints of density waves from the Big Bang era. Combined with data on сверхновых, this indicated: тёмная энергия may be neither eternal nor uniform. It sometimes weakens, sometimes strengthens — like an engine that changes its own revs. A model called Mirage gave the clearest signals, but what's more surprising: if this trend holds true, the Universe is destined not for eternal расширение but for a rip — when space itself starts tearing apart galaxies and atoms.
The statistical significance is still low — 2 sigma, like flipping seven heads in a row. We're far from a reliable 5 sigma. Yet each new sky map brings the answer closer: either dark energy is an unchanging property of the vacuum, or a living, evolving entity. And on this hinges whether the cosmos freezes in eternal cold or vanishes in a fiery flash.
🎯 Dark energy makes up about 70% of the Universe's mass-energy. If it isn't constant, the cosmos may end in a rip, not a freeze.