Galaxy Rotation in Voids Tests Inflation ⚡ экспресс
A new independent method for constraining the "running" of the scalar spectral index of primordial density fluctuations is proposed. The method is based on the analysis of coherent galaxy rotation in cosmic voids, which manifests as a redshift asymmetry on opposite sides of the projection of the void's rotation axis. Using numerical simulations from AbacusSummit, a non-parametric model of the redshift asymmetry distribution is constructed, which proves nearly universal for a wide class of cosmologies, including dynamical dark energy models and ΛCDM with different initial conditions. It is shown that the universality is broken only when the "running" of the spectral index deviates from zero: positive "running" leads to a decrease in asymmetry, negative to an increase. Given that non-standard inflation models predict a non-zero "running", and void asymmetry is an observable quantity, the method opens a new path to understanding the mechanism of inflation.
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.