fermionic dark matter

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.

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.

At the center of a galaxy sits a supermassive black hole, surrounded by a vast, tenuous cloud of dark matter. It doesn't shine or heat, but its gravity warps space and changes the rules of the game for everything orbiting nearby.

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.

A neutron star is a city the size of Manhattan that weighs as much as half a million Earths. A teaspoon of its material would outweigh Mount Everest. Now, into this superdense sphere, something invisible and elusive has been mixed — dark matter particles. That's exactly what physicists did in a new study.

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.

Dark matter is invisible to telescopes, but its gravity was revealed half a century ago by Vera Rubin. Since then, physicists have explored dozens of hypotheses, and one of the most elegant is primordial black holes, formed in the first moments after the Big Bang.

Dark matter remains the inaudible bass line of the cosmic symphony — it emits no light, but its gravitational pull shapes galaxies. Vera Rubin first caught this rhythm in the 1970s by observing the rotation of stars.

For a long time, the event horizon behaved like a cosmic dictator: everything that crossed its boundary vanished irretrievably from our Universe. But quantum mechanics, like a dissident's voice, whispered: information cannot simply disappear.

The early universe was a restless place. Space trembled with gravitational waves — ripples in the very fabric of reality. In this churning cauldron, dark matter is thought to have been born. But the newborn particles had no mass: it had to come from somewhere. Usually, the Higgs field is responsible for mass.

Spacetime is not empty: it shivers. After the Big Bang, the universe was filled with a hum of gravitational waves, like the low rumble of a giant bell. In this ripple, as it turns out, particles of dark matter, the invisible substance that holds galaxies together, can be born. But the previous idea had a snag.

Imagine a translator working in a noisy hall. The hum of voices, the clatter of dishes, fragments of other people’s conversations: it seems they should constantly make mistakes. But by the end of the day, their notes match perfectly with what they would have written in the quiet of an office. This is roughly how the quantum rule known as the axial anomaly behaves.

A lump of dark matter drifts through the void — invisible, almost intangible. No one knows what it's made of, but a new study suggests viewing it as a drop of quantum liquid. Two kinds of fermion particles — call them "heavy" (ψ) and "light" (χ)—exchange signals via a third mediator particle (φ), like floats tied to a single line.

Deep underground in Japan, a huge tank of ultrapure water waits for rare visitors — neutrinos arriving from distant stellar explosions. Such guests are few and far between: over years of observation, Super-Kamiokande registers only a handful of events.

Dark matter is the invisible scaffolding that keeps galaxies from falling apart. Back in the 1970s, Vera Rubin showed that without it, stars on the outskirts would fly away like a carousel without its bolts. Ever since, scientists have been hunting for the particles that make up dark matter.

In a dark room, a glass bead the size of a dust grain hangs on a laser beam. Beneath it are two mirrors: one aluminum, one silver. If axions (light, invisible particles that could make up the mysterious dark matter) whiz by, they exchange with the mirror atoms, and the bead shifts ever so slightly.

In the world of elementary particles, there's a long-standing puzzle: why are the masses of the electron, muon, and tau particle so vastly different? And why are quarks, the building blocks of protons and neutrons, also split into three generations with sharp jumps in mass?

The end of the Universe is not just the fading of light. If dark energy, the mysterious substance accelerating cosmic expansion, tears it apart in a Big Rip scenario, or if expansion reverses into a contraction that pulls everything back to a point like a big bang in reverse, a…

If you squeeze a handful of sand in your fist, it first compacts, but then starts to resist — the grains have nowhere left to go. In the depths of a neutron star, something similar happens, except instead of sand grains, you have elementary particles, and instead of your hand, you have monstrous gravity.

A flat crystal of charged atoms suspended in an electromagnetic trap behaves like a perfectly calm pond. The slightest breeze, and ripples spread across its surface. This 'pond' catches the splashes from dark matter particles and the ripples of spacetime — high-frequency gravitational waves.

In the crystal Rb1-xV2Te2O, the spins of vanadium atoms arrange in a checkerboard pattern: each spin is surrounded by opposite spins. This pattern is called G-type antiferromagnetism. Neutrons passing through the sample scatter off this pattern and reveal its geometry, like light from a flashlight shining through blinds casting stripes on a wall.

A black hole is not just a void but a massive object that warps the space around it. If it finds itself in a cloud of invisible dark matter, matter that emits no light but makes itself known through gravity, its behavior changes.

Physicists trapped a cloud of lithium atoms between mirrors. Light bounces inside, like in an echo chamber, forcing the atoms to emit synchronously — resulting in superradiance, akin to a choir where voices merge into a single thunder. Like a stadium chanting in unison: each whisper turns into a deafening rhythm. The secret is density.

Although invisible, dark matter’s gravity governs the motion of stars and galaxies. It was first proposed by Fritz Zwicky in the 1930s, and later confirmed by Vera Rubin. Scientists have long suspected it accumulates around black holes, but direct proof was lacking.

The cosmos is filled with invisible dark matter, which betrays itself only through gravity. Its existence was suspected by Fritz Zwicky and confirmed by Vera Rubin.

Dark matter is five times more massive than ordinary matter, yet it emits no light. Its nature remains unknown. One candidate is the ultra-light axion particle. Axions could pierce right through the planet, barely noticing atoms.

The enigma of dark matter was already studied by Fritz Zwicky and Vera Rubin. For decades, it was depicted as a cold, listless skeleton that only draws galaxies together.

The law discovered by Wolfgang Pauli forbids identical particles from occupying the same spot. Hence, in cold matter, a Fermi sea is born: particles, like water, fill energy levels from bottom to top. The shape of the sea's surface — including 'islands' of emptiness — dictates the properties of the whole system.

Dark matter is the invisible scaffold of the cosmos, its existence betrayed by whirls of galaxies to Fritz Zwicky and Vera Rubin. What it is made of remained a mystery for half a century. A new hypothesis paints an unusual picture.

In general relativity, a black hole has long been regarded as a perfect mirror: no matter what fields fall onto it, it does not deform. The tidal Love numbers, which measure how a body deforms under an external tidal field, turned out to be zero for scalar, electromagnetic, and gravitational perturbations.

Two actors on the same stage. One is a fermion, finicky and demanding, hard to make follow the rules of a quantum simulator. The other is a boson, easygoing and undemanding, ready to take any role. The director hopes the audience won't notice the substitution.