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rmoh13
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Why do scientists think that dark matter annihilates just like antimatter? How is it that dark matter during annihilation can produce light when it cannot emit or absorb light itself?
This is backwards. It is much easier for dark matter to have significant annihilation when you collect large amounts of it than for it to have significant decay. Also, we do not know that it annihilates, but it is a feature of many popular dark matter models.newjerseyrunner said:They don't, in order for it to exist this long, it should not annihilate in any way. It might decay, but that's not the same.
Yes it does. Dark matter producing light in annihilations or decays are generally doing so in suppressed processes or by the secondary interactions of the annihilation or decay products.newjerseyrunner said:Just because something doesn't interact with light doesn't mean that it can't produce it.
You can easily take care of this by giving the produced particles more kinetic energy. There is no a priori need to emit additional photons. If the produced particles are charged, there is however a possibility that this occurs.newjerseyrunner said:All interactions in the universe must obey the law that energy can not be created or destroyed, so if you have a 10TeV particle decaying into 2 4.8TeV particles, the universe must use that extra .4TeV for something, if there is no stable particle at that size, it's emitted as one or two photons.
Dark matter is likely made up of nearly equal parts matter and anti-matter. The dark matter anti-particles would naturally annihilate with the particles, though obviously this effect has to happen quite slowly in order to allow so much dark matter to remain after billions of years.rmoh13 said:Why do scientists think that dark matter annihilates just like antimatter?
During annihilation (or decay), dark matter could emit charged particle/anti-particle pairs which do emit light.rmoh13 said:How is it that dark matter during annihilation can produce light when it cannot emit or absorb light itself?
This is not really true. In many models, dark matter is a Majorana fermion, meaning that it is its own antiparticle. If this is the case then there is no way of defining anti dark matter which is different - it is still going to annihilate though.Chalnoth said:Dark matter is likely made up of nearly equal parts matter and anti-matter.
Scientists believe that dark matter annihilates because it is the most plausible explanation for the observations of the universe. Dark matter is thought to make up about 85% of the matter in the universe, and its presence is inferred through its gravitational effects on visible matter. However, it does not interact with light, making it difficult to directly observe. The annihilation of dark matter particles would produce gamma rays, which can be detected and studied, providing evidence for its existence.
There are several lines of evidence that support the theory of dark matter annihilation. One of the strongest pieces of evidence is the observation of cosmic microwave background radiation, which shows an uneven distribution of matter in the universe. This distribution is consistent with the presence of dark matter. Additionally, observations of the rotation of galaxies and the gravitational lensing of light also support the existence of dark matter and its role in the structure of the universe.
Dark matter annihilation is different from regular matter annihilation in several ways. First, dark matter particles are thought to be much more massive than regular matter particles, meaning that when they collide, they produce much higher energy particles. Additionally, dark matter particles do not interact with each other, so they can only annihilate when they come into contact with regular matter particles. This makes the process much less frequent and more difficult to observe.
The potential implications of dark matter annihilation are still being explored by scientists. One possibility is that the annihilation of dark matter particles could produce excess gamma rays, which could help us to understand the nature of dark matter and its role in the universe. Additionally, if dark matter particles are found to be their own antiparticles, their annihilation could help explain the abundance of regular matter in the universe compared to antimatter.
Scientists are using a variety of methods to detect dark matter annihilation. One approach is to search for excess gamma rays in regions of the universe where dark matter is thought to be concentrated, such as the centers of galaxies. Another approach is to look for evidence of dark matter annihilation in the cosmic microwave background radiation. Scientists are also conducting experiments in underground facilities to directly detect dark matter particles and study their properties.