Is Dark Matter Composed of Low-Mass Particles?

In summary, the diffused distribution of dark matter as halos over galaxies does not necessarily imply that dark matter is made up of low-mass particles. While there are some constraints on the mass of dark matter particles, particularly in scenarios where they are "thermal freeze out," there is no strong evidence to suggest that dark matter is exclusively made up of particles within a specific mass range. In fact, dark matter candidate papers have proposed a range of masses, from 10-26 GeV to asteroid size and beyond.
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Does the diffused distribution of dark matter as halos over galaxies imply dark matter is made up of low-mass particles?
 
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No.

Assuming, that dark matter particles are "collisionless" there is very little constraint regarding particle mass.

For a "thermal freeze out" sub-type of dark matter there is a viral relationship between mass and mean-velocity of dark matter, this puts a lower and upper bound on dark matter mass from the extent of large scale structure in this scenario. But, there is no likelihood that dark matter is "thermal freeze out" dark matter.

But, in the general case there are not strong limits. Dark matter candidate papers range from candidates with 10-26 GeV and up to at least asteroid mass.
 
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FAQ: Is Dark Matter Composed of Low-Mass Particles?

What is dark matter and how does it affect the mass of galaxies?

Dark matter is a type of matter that does not emit or interact with light, making it invisible to telescopes. It is believed to make up about 85% of the total mass in the universe. Dark matter affects the mass of galaxies by exerting gravitational forces on visible matter, causing it to clump together and form structures such as galaxies and galaxy clusters.

How do scientists measure the mass of dark matter halos?

Scientists use a variety of techniques to measure the mass of dark matter halos, including gravitational lensing, galaxy rotation curves, and simulations. Gravitational lensing involves observing the bending of light from distant objects by the gravitational pull of dark matter. Galaxy rotation curves measure the speeds of stars and gas in galaxies, which can be used to calculate the mass of the dark matter halo. Simulations use computer models to simulate the behavior of dark matter and its effects on visible matter.

How do dark matter halos form?

Dark matter halos are thought to have formed from the gravitational collapse of primordial gas and dark matter in the early universe. As the universe expanded, regions of higher density attracted more matter, leading to the formation of dark matter halos. Over time, these halos grew in size as more matter was drawn into them by gravity.

Can dark matter halos be detected directly?

No, dark matter halos cannot be detected directly because they do not emit or interact with light. However, scientists can indirectly detect the presence of dark matter through its gravitational effects on visible matter.

What is the current understanding of the distribution of dark matter halos in the universe?

The current understanding is that dark matter halos are distributed throughout the universe, with larger halos containing more mass and smaller halos containing less mass. These halos are thought to be interconnected, forming a cosmic web that spans the entire universe. The exact distribution and properties of dark matter halos are still being studied and refined by scientists.

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