Inside a supercomputer, fifteen stable wave clumps — solitons — collide to form a halo of dark matter. These waves obey an equation that Erwin Schrödinger derived for electrons at the beginning of the 20th century, but now they paint a portrait of a giant galactic cocoon. The Fuzzy Dark Matter model — dark matter made of ultralight wave-like bosons — proposes that the invisible substance behaves not like a swarm of particles but like a field, and this field interferes with itself, like ripples on a sea surface. Each interference wave is a quantum superposition of countless bosonic particles, giving rise to fine-grained clumps and rarefactions of density (granularity). Astrophysicists have long wondered: does the ordinary gas floating in the same halo feel these fast ripples? Or does it sway only under the slow, averaged swell of gravity?

To find out, the CAFE-FDM code entered the scene, solving the full system: gravity is described by Poisson's equation, the quantum field by Schrödinger's equation, and the gas by Euler's equations. The gas was set across a wide temperature range — from near absolute zero to a thousand degrees — and the whole ensemble was allowed to "cool down" from its violent birth, reaching virialization (equilibrium after collapse). Then, like a garland of sensors, 16 virtual lines pierced the computational volume, recording density fluctuations of both dark matter and gas over time. These time series were processed with Spectral Analysis tools: autocorrelation — a measure of a signal's similarity to itself — and cross-correlation between components were computed.

The results revealed a clear hierarchy. FDM oscillations damped quickly, like ripples from a stone thrown into water; gas, on the contrary, remembered its motions ten times longer, like a deep swell rocking a large ship. But most telling was the cross-correlation portrait: the mutual link between ripples and swells was almost absent. Once the system settled down, the gas component stopped following the tiny shivers of dark matter. In other words, baryonic gas responds only to the global slope of the gravitational potential — to the averaged "mountain" of density, not to its micro-relief. This conclusion holds for all tested temperatures.

For dark matter hunters, this message has a bittersweet taste. On one hand, the hope of directly seeing quantum ripples in the motion of stars or gas dims: nature has installed an effective low-pass filter. On the other, the discovered time hierarchy itself becomes a fine diagnostic blade. Future simulations incorporating magnetic fields, gas cooling, and star formation may change the picture; perhaps secular accumulations of effects over billions of years will leave an imprint. Along the edge of the central Bose-Einstein condensate — the densest clump — fluctuations may be stronger, and they remain to be explored.

The ocean of dark matter continues to hide its nature. The ripples on its surface are too swift for the heavy waters of gas, and we see only the lazy swell. But this ocean fills the entire galaxy, and by learning to read the rhythms of the swell, astrophysicists may someday reconstruct the portrait of the invisible waves from their long-term whispers.