In the first moments after the Big Bang, the universe breathed — not in the usual sense, but in the rhythm of expansion and contraction of the primordial plasma. The era of inflation (ultra-fast expansion) stretched tiny quantum fluctuations to cosmic scales, creating density waves. If superheavy particles existed at that time, they added a special rhythmic pattern to this ripple — like a stone thrown into water leaves expanding circles.
A team of astrophysicists recreated this process in a computer simulation. They traced how, under the influence of gravity, billions of particles of dark matter gather into giant clouds — halos (future cradles of galaxies). Then they measured the bias — how much more strongly halos cluster compared to ordinary matter. The result was surprising: the bias is not monotonic but oscillates — it strengthens and weakens with a certain rhythm. The frequency and phase of these oscillations depend on the mass and internal density of the halos: for more massive and compact ones, the peaks shift to different scales.
Such a signal is especially valuable because its periodicity makes it difficult to fake with instrumental noise. Now scientists plan to search for similar rhythmic oscillations in real galaxy catalogs. If the search succeeds, we will be able to peer into the inflation era and learn what the world was made of at its deepest foundation.
The cosmological collider isn't science fiction: it's the Universe itself at $10^{-32}$ seconds old. The temperature then reached $10^{29}$ kelvin, and collisions were 10 trillion times more energetic than at the Large Hadron Collider.
In Carl Sagan's 'Contact,' an extraterrestrial intelligence encodes information in a pulsar — here the Universe itself has left a 'message' in the distribution of galaxies, which we are only beginning to decode.