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Dark energy may be losing energy: explaining strange behavior ⚡ экспресс

Original: "Dissipative Dark Energy can explain the DESI phantom crossing"
A subtle friction in dark energy explains why it changes — hinted at by the DESI telescope.
Abstract

Dark energy is the mysterious force speeding up the universe's expansion. Recent observations hint that it might change over time and even cross a weird boundary—the phantom divide. A simple idea offers an explanation: dark energy slowly leaks energy, like a rolling ball that gradually slows down, no exotic physics required. Could such a straightforward fix solve this cosmic riddle?

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In the late 1990s, astronomers including Saul Perlmutter discovered that the universe is expanding at an accelerating rate. The cause was dubbed dark energy — an invisible force stretching the cosmos. For a long time, it was thought to be constant, but fresh data from the DESI telescope, which studies millions of galaxies via their light, showed: around 6 billion years ago dark energy changed its behavior, crossing a critical threshold beyond which its influence becomes even stranger. Physicists described this field like a pendulum. In a standard model, a pendulum meets no resistance and swings forever. But if you put it in a very thick fluid, it starts losing energy due to friction. Similarly, dark energy experiences an ultra-weak ‘friction’ that dissipates its energy and makes the expansion of the universe accelerate differently. No exotic hypotheses — just a natural energy loss. Previously, such a transition would have doomed the universe to a ‘Big Rip’ — a catastrophic end, but the subtle friction cancels this scenario.

🎯 The density of dark energy is so tiny that within the volume of Earth, it would amount to just a couple of kilograms — yet on cosmic scales, it determines the fate of the universe.

Scientists
Alan GuthAndrei LindeGeorges LemaîtreJames PeeblesAdam RiessBrian Schmidt
Tags
dark energy expansion of the universe galaxy spectroscopy
Laws
Friedmann equationsHubble's lawDoppler effectMaxwell's equationsPlanck's lawPlanck–Einstein relation
Original: arXiv:2606.04886 · CC BY 4.0 · bridge42worlds