Dark Matter Formation

  1. I'm by no means a astrophysicists but I love reading, talking and studying all I can on the subject. I have a question on the original formation of dark matter. Could it be plausible that the formation of dark matter be the end result of the antimatter/matter collision right after the Big Bang? Could it be the remnants of that explosion, seeing that supermassive stars collapse into black holes and smaller a stars produce massive nebulas could this explosive have produced something far stranger such as dark matter. Please correct me if I'm wrong but don't both antimatter and dark matter produce gamma rays as well as neutrinos. Are there any theories on this or is it not plausible?
     
  2. jcsd
  3. phinds

    phinds 9,371
    Gold Member

    Since WHAT dark matter is is unknown, your question cannot be definitively answers but I think not since matter/anti-matter collisions are understood and dark matter is not.

    The remnants of WHAT explosion? Have you been watching the History Channel pop-science shows?

    Since dark matter seems to have been around pretty much forever, it MUST be the result of some process during the early part of the universe, but WHAT is unknown.

    Dark matter can't possibly produce gamma rays since it does not interact with itself or with normal matter.
     
  4. Well that helps, the way I understood it that matter and antimatter were produced during the Big Bang of the same quantities and cancelled each other about leaving only a small amount of matter left. Not sure were I heard that dark matter emitted gamma rays or if I even did. Did antimatter and matter not collide after the Big Bang!
     
  5. phinds

    phinds 9,371
    Gold Member

    Yes, matter and anti matter collided after the big bang and almost totally obliterated each other as you said, resulting in gamma rays, neutrinos, and other stuff. WHY there was a mis-match between the amounts of matter and anti-matter is a Nobel Prize topic if you want to try to figure I out :smile:
     
  6. I will give it a crack... Refine my theory a little. Thanks
     
  7. phinds

    phinds 9,371
    Gold Member

    Just keep in mind that thinking outside the box is a good thing, but only after you know what's IN the box.
     
  8. That's excellent advise, I haven't heard it put that way. Thanks
     
  9. Is there any good reading material you can suggest in the area of cosmology, physics and astrophysical that are good for the lay person. I can comprehend some of the more complicated material but I really want to expand where I'm at now.
     
  10. What you describe is not too different from the standard thermal relic production that is assumed a lot of the time. Shortly after the big bang the universe was filled with a hot plasma, so there were violent particle collisions going on all the time, violent enough that a whole spectrum of exotic particles being created in them and then subsequently decaying

    The assumption is then that there was a thermal equilibrium in this plasma, so that there is a constant population of all the various particle types for any given plasma temperature T, depending on their production and annihilation/decay rates. As the plasma cooled this population changed, with the heavier exotic particles no longer being produced when the plasma got too cold. In the case of WIMP dark matter, these particles are stable, and so when the plasma expanded and cooled enough there was a so-called "freeze-out" that occurred, where the dark matter decoupled from the plasma and its population remained basically the same from then on, all the way until now (although the particles spread out the universe expands, i.e. the average density goes down).

    This stable population is what we call the dark matter thermal relic.

    I don't know what level of information you are looking for, but this review has some relatively basic discussion of these things around page 7 http://arxiv.org/abs/hep-ph/9710467
     
  11. Thank you for the information and the link
     
  12. Chronos

    Chronos 10,220
    Science Advisor
    Gold Member

  13. Perhaps the difference was that anti-matter and normal matter don't obliterate at the same rate. Maybe matter lasts just a tiny bit longer.
     
  14. phinds

    phinds 9,371
    Gold Member

    I don't see how that can make sense. The obliteration obliterates BOTH particles so the amounts of each are removed from the universe at the same rate.
     
  15. If matter lasted a little longer it might obliterate more than on particle of anti-matter. It's only a guess. I understand what you mean but is it possible that because of the heat and density after the Big Bang that the rates could be different? If matter didn't leave the universe at the same rate it might destroy a little bit more anti-matter over time and leave a universe consisting of matter.
     
  16. phinds

    phinds 9,371
    Gold Member

    I can only restate that the obliteration obliterates BOTH particles ... it doesn't leave one of them around to obliterate another particle.
     
  17. If most all antimatter was annihilated, there must have been much less of it to begin with. I'm not aware of any reason for an asymmetry in favor of matter. It's possible that vast amounts of antimatter exist elsewhere, but I like to ponder the possibility of else-when. Anti-matter has a negative time value, at least on paper. If the math isn't lying, it may have, from the moment it coalesced, set off in the other direction of time. (I'll speak no more of it).

    As for dark matter, I think topology is a much simpler explanation. We can observe some topological deformation, aka: gravity. We may be seeing other consequences of local topology as well, possibly red-****. I'd love to know how Casimir's experiment plays out in a void region. Humanity is notably egocentric. The cosmological principal is suspect. If it doesn't hold, things will be much more interesting.
     
  18. mfb

    Staff: Mentor

    @Stuart: Please give references for your claims. Speculations and personal opinions are not a valid basis for discussions here.
    CP violation has been shown in many analyses.
    There is no indication of that, and I am not aware of any serious model that would fit to this hypothesis.
    It does not.
    Then publish it, if you have an actual model.
     
  19. I said I'd speak no more about antimatter. I didn't mean to assert anything, just share an interesting idea. I can see that I did make a claim about negative time value, on paper, so with due respect, I'll back it. I hope it will suffice simply to refer to Wikipedia for this. http://en.wikipedia.org/wiki/Time_reversal_symmetry. Feynman diagrams also allow depict negative time. (Hope I don't need to cite that).
    Also, a completely unsubstantiated epistemic observation: Entropy doesn't preclude a negative time line from initial conditions.

    If you're aware of CP violation on scale sufficient to account for observed disparity, I'd love to know about it.

    As for dark matter, here are two topological models, as well as two alternates

    http://arxiv.org/abs/astro-ph/0702146

    http://arxiv-web3.library.cornell.ed...102.0825v2.pdf

    http://arxiv.org/pdf/1303.0065.pdf

    http://arxiv.org/pdf/1004.0745.pdf
     
  20. Chronos

    Chronos 10,220
    Science Advisor
    Gold Member

    Scale is irrelevant for CP violation. Particles are unaware of the universe at large.
     
  21. Why not keep this friendly? Scale is valid in that context, but awareness?

    Awareness is not necessarily cognition. The definition of awareness includes having or showing realization. The exclusion principal describes an exchange of information between every electron the universe through which each acquires a unique quantum state.

    If you're going to troll me I'll take you to task. Can you substantiate your claim that particles are unaware of the universe at large?
     
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