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Can torsion avoid the big bang singularity

  1. Jan 15, 2013 #1
    Interesting theory for consideration:

    Cosmology with torsion: An alternative to cosmic inflation

    http://arxiv.org/abs/1007.0587


    Nikodem J. Poplawski
    (Submitted on 4 Jul 2010 (v1), last revised 2 Nov 2010 (this version, v2))


    In this work, we considered the ECKS theory of gravity which is the closest theory with torsion to general relativity. We used the spin density of matter as the source of torsion, which has a natural physical interpretation in the context of the Poincar´e group and does not introduce additional fields or coupling constants....

    Wikipedia:

    [the Einstein–Cartan theory, also known as the Einstein–Cartan–Sciama–Kibble theory or the Cartan–Sciama–Kibble theory is a classical theory of gravitation similar togeneral relativity but relaxing the assumption that the metric be torsion-free. Introducing torsion allows greater freedom to couple classical spin angular momentum to the metric.]

    Avoidance of singularities

    http://en.wikipedia.org/wiki/Einstein-Cartan_theory#Avoidance_of_singularities


    Does string theory offer any additional insights as to how particle spin and space-time geometry interact?

    edit: somewhere I read that including torsion makes the stress energy momentum tensor non symmetric.....Including torsion is what appears to be the source of the high density repulsion.
     
    Last edited: Jan 15, 2013
  2. jcsd
  3. Jan 15, 2013 #2
    Interesting article it seems to imply there is a universe inside every black hole. I've seen various articles posted on the web to that effect. Nice to see the supporting mathematics.

    Can't help you with spin my understanding of spin is limitted.

    edit: Besides me helping answer your questions after reading many of your posts would be like a Kindergarden student trying to teach a math professor how to add 2+2
     
    Last edited: Jan 15, 2013
  4. Jan 16, 2013 #3
    I wonder if this paper was inspired by Smolins idea of Cosmic Natural Selection. I get that its slightly different but the main idea seems the same.
    http://arxiv.org/abs/gr-qc/0205119
     
  5. Jan 16, 2013 #4
    Here are some related discussions on torsion.

    Turns out, it seems to me, torsion and curvature are more closely related than I realized.

    Mentioned in one of these is a description by Roger Penrose and I read that section in his Road to Reality....Apparently the amount of torsion affects the closing of a parallelogram of geodesic edges about a point. He says going in two opposite directions around the parallelogram yields two different points of closure resulting from the presence of torsion.



    Spin Density and Non-symmetric Stress-Energy Tensor
    https://www.physicsforums.com/showthread.php?t=615574&highlight=torsion

    [Interestingly, Stevendaryl answers one of my uncertainties. It turns out the paper I posted here seems to offer one perspective regarding his question. ]

    Stevendaryl:
    Ben Niehoff: [On Wikipedia Einstein-Cartan theory]


    Does torsion make parallel transport direction dependent?
    https://www.physicsforums.com/showthread.php?t=652327&highlight=torsion

    Is frame dragging the same as torsion?
    https://www.physicsforums.com/showthread.php?t=644506&highlight=torsion

    Tom.Stoer:
     
  6. Jan 16, 2013 #5
    Marcus makes the following point in this thread, which seems to address one of my questions....

    https://www.physicsforums.com/showthread.php?p=4230463#post4230463



     
  7. Jan 16, 2013 #6
    The main problem I have with the multiverse blackhole models.
    Is that blackholes are more violent when they are feeding. That change in feeding rates would reflect in variations. Stronger during feeding times slower when the BH is not feeding. I'd have to look at what can get by the event horizon to name those variations. The electromagnetic readings would certainly reflect the BH feeding rates. Hence I cannot see us being in an event horizon.

    The work on spin association is however useful so still a good paper.
     
  8. Jan 17, 2013 #7
    Mordred,
    I was more interested in the inflation rather than the black hole aspect of the paper. I did not read details in the paper about a collapsing black hole spawning new universes; however, that seems to happen in general when our side of the horizon is cold,black and empty...at least in the vicinity of the BH.

    [I was hoping someone would offer comments about the robustness of the math underlying the gravitational torsion repulsion at high density eliminating the big bang singularity.]

    But I have seen simulations regarding black holes combining or absorbing matter.

    One is here, http://en.wikipedia.org/wiki/Black_hole

    but there is another around in which black holes are shown to oscillate when combining...and the oscillations dampen after combination.
     
    Last edited: Jan 17, 2013
  9. Jan 17, 2013 #8
    A massive star, that is causally connected, collapses gravitationally to a black
    hole and an event horizon forms. Inside the horizon, spacetime is nonstationary and matter contracts to an extremely
    dense, but because of torsion, finite-density state. In the frame locally moving with matter, this contraction looks
    like the contraction of a closed universe [22, 35]. Such a universe is initially causally connected and anisotropic.
    Extremely large tidal forces cause an intense pair production which generates the observed amount of mass and
    increases the energy density, resulting in isotropization of this universe [32–34]. Additional terms in the Lagrangian
    density containing torsion could also generate massive vectors [36].

    The article is full of references to the multiverse BH model. As I stated prior there would be fluctuations in Radiation/energy levels derived from the feeding rates of the BH. As its feeding there would be higher levels compared to when its matter/energy source is further away form its gravity well.
    There was an article written several years ago that described a BH forming a spacetime bubble that as it expanded formed a long tunnel sperating the BH from the bulge. This tunnel eventually squeezed of seperating the created spacetime with the BH. That scenario could create a universe with constant inherent spin/torsion from a BH.

    I can't help you on the mathematical side, I do enjoy the article as it shows how one can apply spin to general relativity, it is definetely useful in those terms. For those reasons its definetely worth examining. I too had hoped more ppl were interested in comenting on the paper.
     
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