Simple

Dark Energy: A Recipe with a Pinch of Salt ⚡ экспресс

Original: "Impact of a negative cosmological constant on the reconstruction of dark energy in light of DESI BAO data"
· Hao Wang, Yun-Song Piao
arXiv:2601.06656v1 · 2026-01-10 · CC BY · ⏱ 1 min · Cosmology
New research shows: dark energy may contain a tiny negative fraction, like salt in sweet dough.
Abstract

Scientists explored the idea that the Universe might be governed by two components at once: the familiar dark energy (which pushes things apart) and a negative cosmological constant (which pulls things together, like a spring). After crunching the observational data, they found that this model fits the facts a bit better. Could it be that the cosmos is trickier than we thought?

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The universe is expanding faster and faster, like yeast dough in the kitchen. This expansion is helped by dark energy — the cosmic sugar. Ever since astronomers like Adam Riess noticed the acceleration in the late 1990s, they've been searching for the cause. The simplest explanation: the sugar works with constant strength; physicists denote this strength with the number w, and if w = -1, the push is constant.

But data from the DESI instrument hint at a more refined recipe. It turned out that adding a tiny negative contribution — a cosmic pinch of salt — makes the picture of expansion even more elegant. This salt slightly reins in the runaway rise and, importantly, brings w back almost to -1, resolving long-standing tensions between different measurements.

And here's the surprise: such a pinch of salt turns an absolutely empty universe into a testing ground for quantum gravity — a mathematical arena where theories linking quanta and gravity are tested.

🎯 A pinch of negative energy turns empty space into an arena for quantum gravity — theorists use this geometry to test ideas that unite quanta and gravity.

w = -1
the number w describes the pressure of dark energy; w = -1 means a constant push, like the simplest version of dark energy
Scientists
Alan GuthAndrei LindeGeorges LemaîtreJames PeeblesAdam RiessBrian Schmidt
Tags
dark energy expansion of the universe spacetime curvature
Laws
Friedmann equationsHubble's lawequivalence principleLense–Thirring effectUnruh effectAdS/CFT correspondence
Original: arXiv:2601.06656v1 · CC BY · bridge42worlds