Could Dark Matter Be A Property of Space?

  1. Ok, we have all read that space is expanding, especially in low mass areas between galaxies, as described by GR.
    And that mass bends space, like seen in gravitational lensing.
    My question is whether on larger scales and masses, like on the size of galaxies, space itself is warped?
    The properties of space are warped to such an extent, that we perceive it as gravitational effects of missing dark matter.
    The flat rotational curves of galaxies are a direct result of the perceived gravitational well.
    There isn't a halo of dark matter, with a mass four to seven times the observed matter, composed of some unknown heavy
    WIMP particle, but rather the properties of space are warped on such large scales by mass.
    Even more so in galactic clusters.
     
  2. jcsd
  3. It would be even more interesting if dark matter and dark energy, are related by the same property of space. Mass changing the properties of space in a way we observed as dark matter, and space outside of matter interactions, observed as an accelerating universe, we label as dark energy.
     
  4. Space itself doesn't have a property. Space itself is simply geometric volume. That volume is filled with the contents of the universe. That being said the largest contributors to whats referred to as the space geometry is as you noted dark energy and dark matter. The energy-density relations between the two with radiation and matter included. Determine the geometry and expansion history. However the two are otherwise unrelated.

    As far as space on large scales being as you said warped. A significant curvature would affect how light travels. Angles of a triangle would not add up to 180 degrees. We use points on the CMB to measure how light paths is influenced. The WMAP and PLANCK data sets show that the geometry of the universe extremely close to flat.

    this article as well as others on my website covers the geometry relations
    http://cosmology101.wikidot.com/universe-geometry

    see my signature for further articles
     
  5. Bobbywhy

    Bobbywhy 1,908
    Gold Member

    Jkarpin2, you ask a question and then immediately answer it with your personal theory. Regardless of how interesting or plausible your idea(s)may be, I think that posting personal theories is not allowed here. You may want to check our rules of membership.
    Cheers, Bobbywhy
     
  6. Well, not sure with your answer. If space between galaxies can expand outside the influence of matter, can it not contract or warp in the presence of matter. Isn't that what a gravitational field is compared to, a warping of space-time.
    Most physicist's believe space is not empty, but a foaming brew of virtual particles.
    So I'm thinking why not talk in terms of the properties of space.
    In the Einstein field equations, mass tells space-time how to curve, and curved space-time tells mass how to move.
    In galactic rotational curves and galactic clusters, curved space-time appears to be causing galaxies and stars to move faster than what the observed mass could produce. Thus the search for dark matter. MOND has had some success with rotational curves, but seems to fail with clusters and gravitational lensing. Dark matter fits our simulations of cosmology and galaxy formation, but all attempts to find WIMPs have to date been unsuccessful.
    Some physicists seem to hint, they are just not there, especially those thought to exist within super symmetry theories.
    So why not take a step back and attach a property to the definition of space-time that accounts for dark matter in the presence of mass on galactic scales, and accounts for dark energy and the expansion of space, as well as it's newly discovered acceleration, within the voids.
     
  7. We have located forms of WIMP's, Neutrinos. MOND also uses dark matter, though their form is different (dipole dark matter). WIMP's are hard to detect by there simple nature.
     
  8. Well, neutrinos fall into the category of hot dark matter. Their relativistic speeds and mass characteristics do not fit the models of cold dark matter. With cosmology defining the percentages of hydrogen, helium, and other trace metals at the Big Bang, and all other nuclear reactions within stellar interiors and supernovas, including the requirement of neutrinos in those reactions, producing all other elements, as understood within the standard model, it's hard to see where dark matter fits in.
    Other than gravitational effects.
    Massive dark matter halos are required to keep spiral galaxies stable.
    Otherwise they would tear apart.
    The same is said for galactic clusters.
    Well my challenge is to assume dark matter does not exist.
    Construct a set of field equations that accounts for galaxy rotation curves, galactic clusters, and gravitational lensing.
    Include a property of space that appears as dark matter when applied to mass concentrations on galactic scales,
    and appears as the expansion / acceleration of space within the voids.
     
  9. Bobbywhy,

    I did not find any restrictions in the forums guidelines in regards to the type of questions I was asking.
    If my posting is inappropriate to the forum, I apologize.
    I was looking for a lively dialog on the subject, with those who have a deeper understanding of GR, given the current results to detect dark matter at the LHC and at deep mine shaft detectors.
    Again if this topic is not within scope, please remove it from any further conversations.
     
  10. No neutrinos do not fall into the category of hot dark matter, neutrinos is its own particle species. Hot dark matter was one possible forms of dark matter, however the dark matter today is cold dark matter. MOND as you said tried to remove the dark matter component, however it failed to do so as it requires dipole dark matter in certain distribution curves.

    by the way there is new evidence that supports dark matter as possibly being sterile neutrinos. With possible observational evidence. However its still under debate

    http://arxiv.org/abs/1402.4119 and http://arxiv.org/abs/1402.2301

    by the way dark matter took quite a long time to be accepted, more scientists than you can imagine have tried to replace the dark matter component. This site however does not support the development of personal theories. Discussion of theories are restricted to peer reviewed theories with peer reviewed support. So MOND is acceptable to discuss for example.
     
    Last edited: May 16, 2014
  11. Bobbywhy

    Bobbywhy 1,908
    Gold Member


    Jkarpin, Thank you for your considerate response. I have no control over what posts appear here. My suggestion was based on this entry under "SITE INFO" at the top of each page:

    "Discussion Guidelines

    Generally, in the forums we do not allow the following:

    Personal theories or speculations that go beyond or counter to generally-accepted science"

    Since Dark Matter is now generally-accepted science, and since you have not posted any peer-reviewed reference(s) which buttress your claims or that discuss your challenge, I have requested our Monitor to look into this for all of us. Only he or she has the authority to close this thread, if deemed inappropriate.

    By the way, I share your idea about the great challenge it is to explain/identify Dark Matter. I'd personally like to see it go away, but of course we don't do science with emotions.

    Cheers, Bobbywhy
     
  12. Matterwave

    Matterwave 3,853
    Science Advisor
    Gold Member

    A neutrino is not a WIMP (weakly interacting massive particle). Although they are only weakly interacting, they are certainly by no means massive (in fact, they are so light, one usually treats them cosmologically like radiation). The neutrino background is certainly taken into account already and it is many orders of magnitude too small to be a real candidate for dark matter.

    What COULD be a WIMP would be a massive sterile neutrino (4th flavor from the 3 known flavors). These we have certainly NOT detected yet.

    As for the OP's inquiry. I have not seen the calculation done myself, but I have every confidence that the astrophysicists who study galactic motion have taken into account General Relativistic effects. I don't think they are so incompetent as to let such an already available "answer" elude them.

    However, even without doing any calculations, we know that galaxies are not very dense objects (a star every few light years or so does not make it dense!). Therefore, although the "total curvature" over the entire galaxy is appreciable (galaxies make for good gravitational lenses, for example), the intra-galactic dynamics should not be affected much by general relativity (I expect metric deviations from the Newtonian case to be small).
     
  13. D H

    Staff: Mentor

    Discussions of personal theories are not allowed at this site.

    Thread closed.
     
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