Dark Energy: How a New Survey Changes the Picture ⚡ экспресс
Using baryon acoustic oscillations from DESI DR2 data, combined with Type Ia supernova catalogs (Pantheon+, DES-Dovekie, Union3) and a compressed CMB likelihood, scenarios of evolving dark energy were tested. Considered parameterizations: logarithmic, exponential, CPL, BA, JBP, Thawing, Mirage, and GEDE. When analyzing only DESI DR2, evidence for dynamical dark energy arises mainly from LRG1-2 tracers, which yield w₀ > −1, but the limited observables make the conclusion statistically shaky. All models fall into the quadrant w₀ > −1, wₐ < 0, typical of Quintom-B-type scenarios. The logarithmic Bayes factor singles out the Mirage model with inconclusive or moderate evidence across all dataset combinations. Statistical significance remains modest: Nσ ~ 1.1–2.3; no model shows a confident preference for dynamical dark energy based solely on late-time data. The evolution of w(z) shows a phantom crossing near z ~ 0.5, and fDE(z) converges to fDE(0) = 1 in all models.
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.