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Could Dark Energy be concentrated inside galactic bubbles?

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  1. Apr 12, 2013 #1
    Bubble regions devoid of galaxies are seen giving structure to the universe; this is coincident with the observed filament structure of super-cluster complexes of galaxies.

    Similar filamentation is seen in the concentration of fluid boundaries when a (soapy) foam is filled with pressurized bubbles (of air). Note, it is the internal pressure of those bubbles that maintains the bubble boundaries. Further, three or more mutual bubbles will see an accumulation of fuild along the common linear boundary (ie: a filament develops).

    Could it be possible that the bubble regions between the galactic filaments are filled with localized concentration of dark energy?

    As such, the dark energy would push matter (visible and dark) out of the enclosed bubble regions. Collectively the amalgam of bubbles would lead to the accelerating expansion of the the universe.

    What this conjecture may serve is to explain the curious mechanism for the formation of the galactic filaments.
     
    Last edited: Apr 12, 2013
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  3. Apr 13, 2013 #2

    cepheid

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    Hi skeleton,

    Maybe just semantics, but I wouldn't say that the great voids and walls in the distribution of galaxies "give" structure so much as they ARE the structure. In other words, the term structure here refers to inhomogeneity: matter overdensities and underdensities.

    Ok, interesting, but beware of assuming that things that share some qualitative similarities are governed by the same physics.

    In the standard cosmological model, dark energy is considered to be uniform (i.e. the same density everywhere). So I don't think that there are really "clumps" of dark energy.

    The existence of the filaments (or, more precisely, the nature of the large scale structure of the universe) can be explained perfectly well within the framework of lambda-CDM cosmology, without the need to invoke localized "concentrations" of dark energy. See, for instance, something like the Millennium Simulation.
     
  4. Apr 13, 2013 #3
    Thanks for your comments.

    I thought one accepted proposal was that dark energy could be inhomogeneous:
    http://en.wikipedia.org/wiki/Dark_energy

    I could imagine, in regard to my conjecture, that dark energy (concentrated inside a galactic bubble) might be a vector field that is related to the surrounding galactic filaments of visible and dark matter. The more matter aggregates along the filaments, the more dark energy (field) occurs within the coincident bubble regions.

    If the dark energy (field) can act on the matter, then the matter can influence (counter reaction) the energy field. Such influence could be that the filaments of matter are, in-turn, confining the energy field into the void bubble regions. This develops a self-perpetuating mechanism that foster the evolution of larger bubble regions and large galactic filament structures.


    Thanks for the tip on the Millennium Simulation. So, if I understand correctly now, that: galactic filaments can naturally form from an initial homogenous early universe (Big Bang) that had uniformly distributed matter and energy.
     
    Last edited: Apr 13, 2013
  5. Apr 14, 2013 #4

    cepheid

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    Maybe. I don't know much about this.



    Yes, simulations like this show that the growth of large scale structure that is quantitatively very similar to what we observe at the present day can be explained within the framework of the Lambda CDM model (a model in which dark energy takes the simplest form of a cosmological constant). Structures like this can arise in a universe that began in a state very close to homogeneous, but with tiny fluctuations to the spacetime metric that were seeded by Inflation (or caused by something else, although Inflation is a leading theory for how they arose). Inflation took quantum fluctuations and expanded them to macroscopic size. Some of these perturbations to the metric corresponded to variations in the matter density that grew under self-gravitation with time, leading to the growth of structure.
     
    Last edited: Apr 14, 2013
  6. Apr 14, 2013 #5

    Chronos

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    The concept of dark energy as a form of 'energy' [e.g., such as EM radiation or kinetic energy] is disfavored by most cosmologists, who prefer the term cosmological constant. The cosmological constant is a geometric property of spacetime itself and often referred to as 'curvature' to capture the geometric flavor of the idea. This is not dissimilar to the GR picture of gravity, which is the geometry, or curvature, of spacetime in the vicinity of a massive object.
     
  7. Apr 14, 2013 #6

    cristo

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    I don't think most cosmologists disfavour the idea of a dynamical dark energy as opposed to a cosmological constant, mainly due to the fact that predictions of the constant's value from fundamental physics is many, many orders of magnitude higher than that observed in the universe. A lot of future observational power will be put in determining the equation of state of dark energy, and testing for a deviation from w=-1.
     
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