The very first moments of the Universe's life resemble tuning a complex musical instrument. Quantum fluctuations, stretched by rapid inflation, became the 'notes' from which galaxies later formed. In the new work, physicists considered an unusual opening chord — a superoscillating state. In this state, a set of simple waves with a limited frequency range creates, through interference, a region with much faster phase oscillations. The birth of the Universe in such a model begins not with a smooth hum, but with a quiet, yet very winding whisper.

This whisper leaves a trace — a narrow spike in the spectrum of primordial perturbations, like a sharp peak on a flat line. The peak's parameters, its position and height, are rigidly set by the initial quantum construction, not tuned to experimental data. However, when this signal reaches us through the cosmic microwave background (CMB), the same thing happens to it as to a complex pattern projected onto an uneven screen: fine details get smeared. Calculations using the CAMB code showed that projection onto the celestial sphere weakens the oscillatory part of the signal by about a factor of three compared to a naive estimate.

Analysis of Planck satellite data has already imposed a constraint: the strength of such an effect does not exceed a few percent of the main signal. But the key conclusion of the work lies elsewhere: it points to where to look next. Future galaxy surveys, such as Euclid, will either detect this quantum pattern or convincingly show that the initial conditions were much simpler.