primordial black hole

Far away in the constellation Cancer, 3.5 billion light-years from Earth, a pendulum clock is ticking. The pendulum is a secondary black hole orbiting a much more massive primary.

A stroboscope in a dark room picks out fleeting shadows from the crowd, shadows the eye cannot catch. A primordial black hole the size of a virus, passing in front of a distant star, briefly magnifies its light for a few seconds, like a magnifying glass held over a bulb.

At the heart of nearly every large galaxy sits a supermassive black hole. Usually it behaves quietly, but sometimes, like a waking volcano, it spits out narrow plasma jets. These jets glow in the radio band, making the galaxy 'radio-loud.' Astronomers have long known this happens, but they couldn't catch the very moment of switching on.

In the first moments after the Big Bang, matter and antimatter should have been created in equal amounts. But today, everything around us is ordinary matter, and antimatter is almost nowhere to be found. Where did it all go? The standard answer: a tiny imbalance in favor of matter wiped out almost all antimatter.

In the first moments after the Big Bang, matter and antimatter should have been created in equal amounts. But today, everything around us is ordinary matter, and antimatter is almost nowhere to be found. Where did it all go? The standard answer: a tiny imbalance in favor of matter wiped out almost all antimatter.

A campfire that doesn't go out all at once but smolders for hours because the wood inside still holds the heat of the past flame. That's roughly how the memory effect works for black holes. Normally, a tiny black hole with the mass of a mountain should evaporate in fractions of a second, scattering particles like sparks.

A campfire that doesn't go out all at once but smolders for hours because the wood inside still holds the heat of the past flame. That's roughly how the memory effect works for black holes. Normally, a tiny black hole with the mass of a mountain should evaporate in fractions of a second, scattering particles like sparks.

A spinning top whirls so fast that the air around it starts to rotate in unison. A black hole behaves in much the same way: if it spins, it can transfer its energy to particles that happen to be nearby. This process is called superradiance: it's like an echo in the mountains, but instead of sound, new particles are born.

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.

A black hole is not an eternal vacuum cleaner. It slowly loses mass by emitting particles, much like a heated stone cooling as it radiates heat. This process, discovered by Stephen Hawking, is barely noticeable for large holes, but for tiny ones, with masses comparable to a mountain, it becomes a violent evaporation.

A black hole's shadow isn't just a black circle. Usually, we see a dark void surrounded by a glowing ring of hot gas. But if a black hole wasn't born from a dying star but has existed forever, its shadow might hide a surprise. An eternal black hole is a solution to Einstein's equations with no past and no collapse.

Cosmologists are facing a curious situation: two reliable tools draw slightly different maps of the same universe. One tool is the map of ancient light (the cosmic microwave background), and the other is the map of galaxy distribution. They broadly agree, but in details they diverge.

Two black holes circle in a cosmic dance, spiraling closer together. In the end, they merge into one, and that moment unleashes a powerful burst of gravitational waves, ripples in spacetime itself. But what remains after the merger?

A black hole is not just an abyss. It is a seething cauldron whose temperature rises as it evaporates. The authors of the study found that when the heat reaches a critical threshold, the hole seems to boil. It emits superheavy particles — the very ones that exist on a scale where any theory of gravity collapses.

When two black holes merge, the newborn object rings like a bell. This ring, gravitational waves of a special kind, astronomers call quasinormal modes (particular damped oscillations). They decay quickly but still reveal the black hole's mass and spin. The question is where in space this ringing begins.

A black hole is not an absolutely black bag. In 1974, Stephen Hawking showed that it glows — faintly, but continuously. This radiation is born not inside, but outside, right at the boundary from which even light cannot escape. A new study sharpens the picture.

In the first moments after the Big Bang, the universe underwent a rapid expansion — inflation. Space stretched faster than light, and quantum jitters of the vacuum turned into real particles. This is how dark matter, the invisible substance that holds galaxies together, could have been born.

In the first moments after the Big Bang, the universe was a searing 'soup' of particles. As it cooled, phase transitions occurred — much like water turning to ice. At one such moment, magnetic monopoles of dark matter could have been born: tiny clumps of field with a single magnetic pole.

In the first moments after the Big Bang, the universe expanded at an incredible rate — a phase known as inflation. Even the vacuum was restless back then: quantum jitters shook the fields like wind rustling through a wheat field.

Imagine a factory capable of producing a million parts per hour, yet it only makes a hundred. That's roughly how our Universe behaves when viewed through the lens of entropy — a measure of disorder that, according to physics, must only increase. The main "machines" of this factory are supermassive black holes.

A black hole doesn't just spin: it's surrounded by bristles of an extra field (the Kalb–Ramond field). This paper explores how a massive field (waves with mass) behaves near such a black hole when it's almost spinning at its maximum rate. The Klein–Gordon–Fock equation for this field was separated into two independent parts — radial and angular.

A black hole is not a perfect vacuum cleaner. It is surrounded by a swarm of particles and fields, and this swarm alters its fate. In a new study, astrophysicists examined how a massive vector field, a hypothetical form of dark matter, behaves near a rotating black hole.

At the centers of many galaxies lurk giant black holes. They are surrounded by dense clouds of hot plasma that emit a powerful X-ray glow.

A black hole is a gargantuan cosmic whirlpool that drags in everything nearby. But beyond visible matter, an invisible mist can hover in its vicinity — dark matter. Physicists have studied its behavior. Unlike ordinary matter, the field doesn’t necessarily fall through the horizon.

A marathon lasting 13 billion years started with different weights. A hundred solar masses — lighter than some gas clouds. A hundred thousand — gravitational dominance, comparable to an elephant among kittens. That's what black hole seeds looked like, ones that by our time should have turned into supermassive giants.

Forty reddish sparks frozen in the images from JWST. The telescope spotted them in the depths of space, at distances where the Universe was less than two billion years old. These objects are active galactic nuclei — very compact and unusually red. Their color earned them the nickname 'little red dots' (LRDs).

For a whole year, LIGO, Virgo, and KAGRA listened to the trembling of spacetime. Thousands of mergers of black holes and neutron stars left clear signatures. But hidden among them was another signal — a barely audible whisper.

Layer by layer, artifact by artifact — an archaeologist reconstructs the history of an ancient settlement. Similarly, astrophysicists sifting through 259 records from LIGO–Virgo–KAGRA saw a clear layered structure among merging black holes.

A black hole is a place from which nothing can escape. But some theories allow that deep inside, at the quantum level, it might bounce and turn into its opposite — a white hole, which only spews out matter and light. A group of physicists built a computer model of such a transformation.

Eight hundred million years after the Big Bang, and at the heart of a young galaxy a monstrous engine is already throbbing. A black hole with a mass of ten billion suns devours matter so greedily that its radiation should outshine everything around it. But outside, silence.

At the center of a distant galaxy, where a supermassive black hole weighing a hundred million suns spins, space is threaded with magnetic fields. They coil into tight vortices, like a drain in a sink, but instead of water, there's plasma whipped up to near-light speeds.

In the early universe, just a few hundred million years after the Big Bang, astronomers see strange objects — little red dots. They are compact, red, and in their spectra, broad Balmer lines scream the presence of supermassive black holes. But how did the hole manage to accumulate millions of solar masses in such a short time?

The spiral of water draining into a sink spins faster and faster toward the center. In an ordinary black hole, that funnel ends in an infinitely sharp point — a singularity where the laws of physics break down. But this new work considers a different picture: the funnel doesn't taper to a needle but ends in a smooth, swelling bubble.

A campfire burns steadily and long. But when the wind blows, the flame flickers out, leaving only embers. A similar story plays out with the gravastar — a hypothetical object that was supposed to replace the black hole. An ordinary black hole hides a singularity — a point where the laws of physics break down.

A black hole's horizon is not a wall but rather a one-way membrane. Anything that crosses it disappears forever. Stephen Hawking showed that this boundary should glow faintly, emitting particles. But catching such radiation from a real black hole is impossible: it's too far and too dim. Physicists have found a workaround: build a "toy" black hole out of magnetic atoms.

Space is full of invisible waves — ripples in the fabric of spacetime left behind by cataclysms like black hole mergers. An ordinary black hole swallows everything without a trace. But there are hypothetical exotic objects — ultradense clumps of matter without an event horizon (a surface from which not even light can escape).

A swarm of tiny invisible particles, like a cloud of pollen, drifts through space. A black hole sits in its path. Some particles fall in and vanish forever; others swing around the trap and fly away. The physicists built a map showing exactly how much matter gets swallowed and how much survives.

Boiling water in a pot is a good place to start. Bubbles of steam rise, pop, and the surface settles down. Something similar might have happened in the first moments of the universe's life with a special field filling space: bubbles of a new phase inflated and collided, like islands of steam in liquid.

Ten billion years ago, the universe was speckled with strange crimson sparks. The JWST spotted them in images at distant redshifts — compact sources blazing like entire galaxies yet no larger than a tiny central region. Astronomers nicknamed them “little red dots.” Their nature long defied explanation.

At the centers of many galaxies, not only supermassive black holes lurk, but also vast clouds of invisible matter. If this matter consists of ultralight particles, it can gather into dense clumps — a kind of 'star' made of dark matter.