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Dark Energy Is Not Constant: A New Look at the Universe's Acceleration ⚡ экспресс

Original: "Evidence of dynamical dark energy found via the DESI DR2 Lyman$$\alpha$$ forest"
arXiv:2510.21976 · 2025-10-24 · CC BY · ⏱ 1 min · Cosmology General Relativity HEP Theory
Data from the DESI survey suggests that the mysterious force speeding up the cosmos may not be eternal or constant.
Abstract

Scientists used data from a new telescope to study dark energy—the mysterious force accelerating the expansion of the Universe. They found hints that dark energy might change over time, like a wind that strengthens and weakens, rather than staying constant. Is the fate of the Universe written in wavering shadows, or is it just a trick of the light?

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The Universe is a grand highway where galaxies, like cars, are moving apart faster and faster. The gas pedal is controlled by mysterious dark energy. In 1998, Saul Perlmutter, Brian Schmidt, and Adam Riess discovered this acceleration using supernovae, but they thought the pedal was pressed evenly. The new DESI survey, covering 11 billion years of cosmic history, challenges the model of uniform expansion. Scientists measured the recession of galaxies and also studied the light of quasars passing through clouds of hydrogen. These clouds act like road signs: dark lines in the spectrum shift more the faster space stretches. Adding the afterglow of the Big Bang, the team compared models. It turned out that the version with dark energy that 'revs' unevenly—barely touching the pedal in the first few billion years and now flooring it—fits the data slightly better than the constant-speed model. As of now, the statistical significance is below the discovery threshold, but if the trend is confirmed, our understanding of the cosmic 'engine' will change.

🎯 Quasar light leaves a 'road track' of hundreds of dark bands on the spectrum. Each band marks a hydrogen cloud, and its shift reveals the expansion rate at the moment the light passed it. It works like a cosmic speedometer from billions of years ago.

🎬 Science fiction writers eagerly imagine universes with changing physics. In Greg Bear's novel *Eon*, the variability of fundamental forces leads to disasters.

Scientists
Alan GuthAndrei LindeGeorges LemaîtreJames PeeblesAdam RiessBrian Schmidt
Tags
dark energy expansion of the universe supernova hydrogen big bang
Laws
Friedmann equationsHubble's lawCoulomb's lawEinstein field equationsPlanck's lawRydberg formula
Original: arXiv:2510.21976 · CC BY · bridge42worlds