How is dark matter formed? How can there be so much dark matter in the universe?

If you know how it is formed, it is not called dark matter

Dark matter is non-luminous matter that is inferred from astronomical observations to exist in the universe. It is composed of non-luminous objects, halo matter, and non-baryonic neutral particles.

Historically, people have divided possible dark matter into three broad categories: cold dark matter, warm dark matter, and hot dark matter. This classification is not based on the true temperature of the particles, but on the rate at which they move.

Cold dark matter: Matter that moves at classical speeds.

Warm dark matter: particles move fast enough to produce relativistic effects.

Hot dark matter: The speed of particles is close to the speed of light.

Although there can be a fourth classification called mixed dark matter, this theory was abandoned in the 90s of the 20th century due to the discovery of dark energy.

Dark matter - detection experiments.

The detection of dark matter is a very popular research field in the field of contemporary particle physics and astrophysics. For massive weakly interacting particles, physicists may detect WIMP directly through detectors placed in underground laboratories with very low background noise, or indirectly through terrestrial or space telescopes for other particles produced by the annihilation of such particles at the center of galaxies, the center of the sun, or the center of the Earth.

To put it bluntly, dark matter is just a general term for the unknown matter in the universe, not a specific substance...

In fact, dark matter refers to substances that cannot be seen, touched, or seem to exist. Why is there so much dark matter, no one can, but you can think the other way around, why can we only feel so much matter? This may be related to the multidimensional universe and spatial overlap, and there are many hypotheses.

However, I think, my personal opinion, that, like genes, a lot of "matter" is used to make up space, a four-dimensional space. The direct manifestation of this space is gravity. Because gravity is not a force in three-dimensional space, it exists far beyond time, so I think that there is a space composed of unknown matter in more than four dimensions, and the reaction in the three-dimensional world is gravity.

How dark matter is formed......The jury is still out on this issue, because it is not even clear what dark matter really is.

In cosmology, dark matter refers to substances that do not emit electromagnetic radiation on their own or interact with electromagnetic waves. The existence of large amounts of dark matter in the universe is currently known only through the effects of gravity. Dark matter.

Scientists now can't explain how dark matter is formed.

I remember that the membrane theory has an explanation for this, our universe is a holographic membrane, and there are thousands of membrane worlds, between the membranes all material energy information can not pass through, except for gravity, the so-called dark matter is the manifestation of the gravitational penetration of the massive celestial bodies in the adjacent membrane world.

If only I could have asked this question, I might have won the Nobel Prize.

No one here will know ... This is a question that scientists cannot do with you at the moment ...

Isn't it the result of low-dimensionality?

Einstein added the cosmological constant because he believed that the universe should be constant. However, another scientist later discovered that the universe was indeed expanding at an accelerated rate, and that Einstein's initial gravitational equation was not wrong. Subsequent observations showed that the density of matter in the universe was 100 times smaller than the average density value obtained by Einstein, so he published the relevant **, invisible matter of the universe that does not emit light.

Zwicky observed the change in velocity of the comet cluster in space through spectral redshift observations, and the velocity dispersion of objects seen in this cluster was very high, and based on the observed mass of galaxies, the comet cluster at that time was actually a galaxy cluster, it was difficult to keep them in it, and even the visible mass of matter was only a small fraction of the galaxy cluster. Comets are most likely due to the presence of large amounts of dark matter, which are more than 90 times more massive than human galaxies today.

Dark matter particles have a relatively long lifespan. Dark matter still exists because the universe has evolved for 1.3 billion years. It can be inferred that dark matter, like protons, does not decay, or dark matter decays but at a very low rate, usually because it is cold, so it is slower and more massive.

Dark matter particles do not participate in electromagnetic interactions, gravitational interactions between them, and possibly weak interactions, both are weak.

Use the Large Hadron Collider to simulate the beginning of the Big ** and try to discover dark matter. Detect the collision signal between the dark matter sample and the normal sample, the possibility of a collision between the dark matter and the normal matter and send a signal is very small, but because the signal is too weak, it is necessary to block the influence rays of other cosmic matter. Dark matter particles can be annihilated or decayed, and cosmic rays emitted in the process can be detected by detectors launched into space.

Invisible dark matter, this is a special substance, so such dark matter is special and different.

Dark matter is discovered by some astronomers who have discovered the abnormal aggregation of rivers in the universe by observing the universe, and in order to explain this phenomenon that does not conform to gravity with gravitation.

Dark matter may be made up of a hitherto unidentified subatomic particle that is completely different from what scientists call baryons. Baryons are just ordinary matter, found everywhere around us, made up of ordinary atoms made up of protons and neutrons.

In 933, this is how the Swiss astronomer Zwicki estimated the mass of a galaxy cluster. He was surprised to find that the mass of some galaxy clusters "numbered" by luminous matter was much smaller than the mass "weighed" by the movement of galaxies, and the difference between the two was more than 10 times! This means that there are too few luminescent substances in the star cluster, and most of the substances may not emit light!

Zviki calls it "shortage quality" or "traceless quality", meaning that a part of the substance has disappeared without a trace.

At first, no one paid attention to the results of Zviki. Nearly 40 years later, as more and more similar cases occur, astronomers are beginning to understand that there may be non-luminous matter in the universe. They don't emit light, but they have a gravitational pull, so you can feel their presence.

Astronomers refer to this invisible, invisible, material collectively as "dark matter."

There is now more and more observational evidence, such as the morphology of galaxy clusters, the rotation of galaxies, gravitational lensing, the X-rays emitted by galaxy clusters, and the anisotropy of cosmic microwave background radiation, all of which indicate that there may be a large amount of dark matter in the universe.

There are two possible compositions of dark matter:

One is ordinary matter, which is the so-called baryonic matter, such as brown dwarfs, black dwarfs, neutron stars, black holes and other faintly luminous objects. They can participate in electromagnetic interactions, i.e., they can emit light or absorb light. But it is too small, too cold, or too far away to be detected by current telescopes.

However, according to theoretical research, it is not possible for baryonic matter to account for such a high proportion.

So the vast majority of dark matter is probably another substance – non-baryonic matter. Non-baryonic matter does not participate in electromagnetic interactions, does not emit light, and does not absorb light. According to the speed of motion, it is divided into hot dark matter and cold dark matter.

However, the large-scale structure of the universe suggests that there is not so much hot dark matter, so dark matter should be mostly cold dark matter. The most likely candidates for cold dark matter are neutrons, axons, gravitational neutrinos, etc. Neutrons are particles predicted by supersymmetry theory, which are so heavy that they can reach 1,000 times the mass of protons.

However, it is very sparsely distributed in the universe. The axon is also the particle predicted by theory, and its mass is very small, only one part of a hundred trillion protons, but the density is very large. At present, the detection of dark matter particles is still ongoing, and there are no conclusive results.

Dark matter was discovered 100 years ago while observing the movement of galaxies. In terms of gravitational calculations, it seems that the mass of galaxies is not the result of our observations, and it is not explained by error measurements, because the values vary a lot. So, astronomers refer to these invisible substances as dark matter.

Dark matter is so massive that it is about one or two times the mass of stars in galaxies.

At the beginning, some people suspected that dark matter was a material that was not easy to observe in ordinary matter, such as interstellar dust and wandering asteroids, but after thinking about it, they found that there was still a lot of difference. Dark matter is not a black hole, black holes are conventional matter, and black holes are actually not difficult to observe in today's universe. Dark matter is also not neutrinos, which are imperceptible but have very small masses.

Dark matter is a type of matter that acts only by gravity and without electromagnetism. That is, it does not emit light at all, nor does it reflect light. Dark matter meets our regular matter without interfering with each other.

Now that we have seen the gravitational effect of dark matter, we can know its location, dispersion, and mass. Dark matter is extremely widely dispersed, but low in density. As far as the solar system is concerned, we have dark matter all around us, but we don't feel it completely.

Therefore, the astronomy of the solar system does not need to think about the influence of dark matter. Our solar system travels through dark matter. It's as if an airplane is passing through a cloud in the air.

If you look at the extent of the Milky Way, the impact of dark matter is considerable. For example, the galactic motion of stars such as the Sun around the galactic center of the Milky Way is calculated according to the mass and orbital radius, which is too fast to fly out of the Milky Way. Because of the mass of dark matter, stars like the Sun are gravitationally confined to the Milky Way.

If you look at the interaction between galaxies, the influence of dark matter is even greater. If you don't think about dark matter, the trajectory is wrong. The centroid of many galaxies does not coincide with the observed image centroid because of the presence of dark matter, and the centroid of dark matter does not diverge from the centroid of conventional matter.

Dark matter is everywhere and is more than average on a large scale, because it is very difficult to clump. But it's not completely flat. When the group of galaxies and supergroups of galaxies is observed, the main interaction used to be the protagonist of dark matter, and the supergroup of galaxies was involved with dark energy at the beginning, and the value of conventional matter was once insignificant.

It is an invisible substance, which is the main component of the universe, and it is through the interaction of mass matter, so that the universe will expand and produce other particles.

Dark matter in the universe can be understood as being made up of baryonic matter or non-baryonic matter; It is a substance that brings together elements in the universe to form it.

Some substances that humans do not understand, the specific composition of these substances is not clear, and there is no way to observe and determine.