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In the first half-billion years after the Big Bang, galaxies grew like crazy. Gas fell in rapidly and collapsed into stars without any resistance. This period is called 'unimpeded star formation.' It's like frying pancakes on a scorching skillet without a lid: splatters fly, but nothing holds them back.

When you blow up a balloon too quickly, its surface starts to quiver. Something similar happened to space in the first moments after the Big Bang: the universe expanded rapidly, and the very fabric of space began to ripple.

The universe is a vast, dark ocean. We see only the glowing foam on its surface — stars and galaxies. But hidden in the depths are two invisible forces: dark matter, which with its gravity keeps galaxies from flying apart, and dark energy, which, on the contrary, pushes space itself apart, making the universe expand faster and faster.

295 000 meters per second. Not even particles in solar coronal ejecta move that fast. But at the center of the galaxy cluster H1821+643, hot gas does exactly that. The quasar at its heart takes a breath, and its breath stirs everything around for 60 thousand light-years.

Cosmic ripples begin with tiny clumps. 380,000 years after the Big Bang, the universe was nearly homogeneous — density fluctuations were only one part in 100,000. But gravity turned these weak ripples into galaxies, clusters, and giant voids.

The heart of many galaxies is a supermassive black hole. It doesn't just sit at the center; it occasionally flares brightly as it swallows surrounding gas.

The origin of the hot Big Bang is one of the greatest mysteries. The familiar picture: after inflation, the inflaton field transfers energy to ordinary particles, reheating the Universe. Yet dark matter and dark energy hint that nature has hidden sectors.

Dark matter is the invisible scaffold of the universe. It doesn't shine, but its gravity holds stars in galaxies. In some models, dark matter particles can collide and exchange energy, like molecules in warm air.

A blacksmith forges a sword. With each hammer blow, the red-hot metal flattens, but the hammer, the anvil, and the surrounding air all warm up slightly. Part of the impact energy is irreversibly lost as heat — a trade-off familiar to anyone who has ever driven a nail, and it turns out to be the key to the biggest mysteries of the cosmos.

A pond with ripples spreading from a fallen stone. So it is on cosmic scales: a sudden burst of energy in the dark sector, an invisible substance that emits no light, creates ripples in the fabric of space. These ripples alter the path of light particles traveling to us from the very birth of the cosmos. The authors of the new study built a mathematical framework to describe these distortions.

Drop a stone into a pond — ripples spread across the water. The most visible ripple comes from the strongest splash. That's roughly how physicists picture the growth of perturbations around a black hole: if a system has an instability, its 'loudest' component, the one that grows fastest, should show up first.

In the mid-20th century, astronomer Vera Rubin discovered that stars on the outskirts of galaxies were moving too fast — held by an invisible mass. Thus the mystery of dark matter was born. It doesn’t emit light but reveals itself through gravity. The big question: why is there exactly as much as we see?

At the center of galaxy VV 340a lies a supermassive black hole — an object with gravity so strong that even light cannot escape it. It emits a relativistic jet: a narrow stream of matter accelerated to near-light speeds.

The James Webb Space Telescope has spotted a scattering of compact objects in the early universe, nicknamed 'little red dots.' They are too red and too dim to be ordinary quasars, and astrophysicists are scratching their heads over what powers them.