Dark Energy: A Recipe with a Pinch of Salt ⚡ экспресс
Recent DESI data hint at the presence of an anti-de Sitter vacuum, i.e., a negative cosmological constant (NCC), alongside evolving dark energy at low redshifts. Two reconstruction techniques—redshift binning and Gaussian processes—were used to analyze how the NCC affects the dark energy equation of state w(z). Both methods slightly favor the NCC model at up to ~1σ. A degeneracy between parameters reduces the accuracy of w(z) recovery, but as a result, the phantom divide value w=-1 fits more comfortably within the 1σ posterior interval.
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.