Galaxy Rotation in Voids Tests Inflation ⚡ экспресс
Scientists have found a new way to measure the "running" of the spectral index — a quantity describing how density fluctuations changed in the early Universe. The rotation of galaxies in cosmic voids turned out to be sensitive to this parameter: the redshift asymmetry on opposite sides of the rotation axis changes if the "running" is not zero. A model built on simulations is universal for many cosmologies, but breaks down precisely when "running" is non-zero. This means that by observing void asymmetry, we can independently test inflation theories.
In the nearly empty regions of space, galaxies spin in unison, like dancers in the same troupe. This dance creates a difference in light from opposite sides: on one side stretching, on the other compression. This optical shift has become a probe of the first moments after the Big Bang.
Amazingly, the dance depends almost neither on the expansion of the Universe nor on the fickle dark energy. It is disrupted only if the 'clumpiness' of the primordial ripples changed with size — that is, during non-uniform inflation. This subtle characteristic, the running of the spectral index, can be measured directly by observing thousands of voids.
Such a method can confirm the hypothesis of Alan Guth and, within the standard model, fill the gaps. The void holds the key to the beginning — you just need to read the dance of galaxies.
🎯 The most studied void in the constellation Boötes stretches 330 million light-years, but only 60 galaxies have been found in it — and they all spin in unison.
🎬 Science fiction writers populate cosmic voids with ghosts of dead civilizations, but reality turned out to be more interesting: it is in these 'dead zones' that the key to the birth of the Universe is hidden.