The discussion revolves around the nature of dark matter, specifically addressing the concept of dark matter annihilation and its implications. Participants explore theoretical models, the potential for dark matter to produce light, and the differences between annihilation and decay processes.
Participants express differing views on whether dark matter annihilates or decays, with no consensus reached on the mechanisms or implications of these processes. Multiple competing models and hypotheses are presented, reflecting ongoing debate.
Participants note the complexity of dark matter interactions and the various models that exist, including Majorana fermions and asymmetric dark matter, which influence the understanding of annihilation and decay.
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.