New Vector Theory of Gravity challenges GR

Discussion in 'Physics & Math' started by Q-reeus, Jun 9, 2018.

  1. Q-reeus Valued Senior Member

    Messages:
    3,052
    Previously I had dropped tentative support for Carver Mead's G4v vector gravity theory. Partly on the basis of the apparently definitive positive finding for GR-type tensor gravity GW's, and against vector gravity GW's, as mentioned under 'VIII. CONCLUSION' in the jointly authored article https://arxiv.org/abs/1709.09660 linked to here: http://www.sciforums.com/posts/3484693/

    That and a similar negative finding here: https://arxiv.org/abs/1710.03794 is now strongly challenged by A. Svidzinsky with his reanalysis that evidently dramatically turns the tables in favour of his Vector Theory of Gravity:
    https://arxiv.org/abs/1712.07181
    https://arxiv.org/abs/1804.03520

    The theory itself:
    https://arxiv.org/abs/1511.07058
    http://iopscience.iop.org/article/10.1088/1402-4896/aa93a8/meta
    http://iopscience.iop.org/article/10.1088/1402-4896/aa93a8/pdf

    With an interesting Editorial piece that probably should be read first:
    http://iopscience.iop.org/article/10.1088/1402-4896/aa93a9

    Some novel features - gravitons are not fundamental but composite objects formed of massless fermion/anti-fermion pairs. Similar proposal for photons.
    Has the imo absolutely essential feature that for a spherically symmetric mass the metric has exponential form just as in Yilmaz theory. No horizons thus no BH's.
    And just as Stan Robertson showed for Yilmaz theory, the current theory automatically predicts accelerated expansion for universe of the correct magnitude - without requiring any free parameter.

    The one thing not to my liking is it assumes a prior background Euclidean/Minkowski metric.
    The final arbiter though will hinge on whether his finding that LIGO/Virgo etc. GW signatures actually rules out GR-type GW's and rules in vector GW's continues to hold up. There is certain to be savage criticism from GR community, at least for quite some time.
    Will be very interesting to follow developments.
     
    Last edited: Jun 9, 2018
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Q-reeus Valued Senior Member

    Messages:
    3,052
    Wow - such interest here - not.
    Despite the impression of theory freshness given in that Physica Scripta Editorial, it turns out his theory is not that new at all: https://arxiv.org/abs/0904.3155
    Evidently what got it over the line recently re publishing, is the refinements especially specific predictions that have deeply impressed enough GR buffs.
    I intend to update pending further results especially newer combined detector GW analyses. And of course the long awaited EHT results.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Xelasnave.1947 Valued Senior Member

    Messages:
    4,886
    Hi Q-reeus
    I am most interested and thank you for taking your time to present a very interesting post.

    Unfortunately I am not able to comment but I follow your comments with high interest.

    I expect there will be others like me who are interested but unable to comment.

    Please dont lose your enthusiasm.

    Alex
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Q-reeus Valued Senior Member

    Messages:
    3,052
    Thanks Alex. Exciting times are at hand me thinks. I initially held little regard for claims GW 'astronomy' would yield anything really new. That outlook has now changed with a vengeance!
     
  8. Hayden Registered Senior Member

    Messages:
    110
    What is the new vector theory?
     
  9. Q-reeus Valued Senior Member

    Messages:
    3,052
    Please read #1 where relevant links are provided for your convenience!
     
  10. Hayden Registered Senior Member

    Messages:
    110
    Please summarise in brief how it is superior to GR or how it challenges GR.
     
  11. Q-reeus Valued Senior Member

    Messages:
    3,052
    It naturally predicts the correct value for accelerated Hubble 'constant', or equivalently 'DE' fraction = 2/3, without any ad hoc free parameter involved, unlike GR's Lambda.
    It passes all the current observational tests as per Clifford Will's PPN framework (mentioned in both Editorial and main theory paper).
    According to Svidzinsky's detailed reanalysis of a previous finding re LIGO/Virgo GW data, the table are turned - only his vector theory is consistent with the data. Not GR.
    IF that is further confirmed, GR is dead.
    There are no singularities or horizons - thus no conundrums like 'information paradox' or 'firewalls' etc. to fret over, since there is no Hawking radiation in the first place.

    I suggest reading at least the Editorial article linked to, after reading just the intro to the second linked article re reanalysis of LIGO/Virgo GW data. Then if you have some specific criticisms of Svidzinsky's theory, let's have it.
     
    Last edited: Jun 17, 2018
  12. Hayden Registered Senior Member

    Messages:
    110
    Thanks, nice.
    As you say it has potential to kill GR. Only GR or big bang also?
    If big bang also then prediction of correct accelerated Hubble constant seems odd, means where does expansion come from if no big bang type origin.
     
  13. Q-reeus Valued Senior Member

    Messages:
    3,052
    And nice in turn to get some positive response. This place is typically a flaming playground.
    It also has a very interesting explanation for BB that avoids need for hypothetical 'inflaton' field. However it rests on a model for both graviton and photon where both are composite entities formed from massless fermion-antifermion pairs. Obviously different pairs respectively. The intricacies are way over my head but you will find discussion of it in e.g. part 10 here: https://arxiv.org/abs/1511.07058
    I have to rely on the opinion of expert reviewers as to it's tentative correctness. As you may have read in Editorial piece, it got a thumbs-up from some at least.
     
  14. Hayden Registered Senior Member

    Messages:
    110
    The problem is adhocism does not end in astrophysics. This vector theory may solve something but then unwittingly gets into standard model graviton photon fermion anti fermion. And you know at least graviton has no observational evidence, it is sticky physics. What I like most about present models is that all alternative seekers are trying some changes here and there, none is coming up with something different from scratch. They close the leak at point A but then the point B becomes leaky, kind of back to square one.
     
  15. Q-reeus Valued Senior Member

    Messages:
    3,052
    Well the Editorial article reviewers cited there acknowledge that it tentatively solves all such issues from a first-principles basis. No ad hoc Lambda or inflaton has to be tacked on. The quantization aspect yes is required to deal with BB inflationary phase 'naturally', but accelerated expansion post inflationary stage is entirely a classical aspect, as discussed in that article. The 'longitudinal gravitational field' component that is not quantized in Svidzinsky's theory. If it really interests, I suggest studying all that article in detail.
     
  16. Hayden Registered Senior Member

    Messages:
    110
    Precisely, the longitudinal gravitational field component is not quantized, and thus the difference in probable explanations for GW. I am of the opinion that the gravity as such does not have any inherent transverse component, this could be due to spin of the object only, kind of frame dragging effect.
     
  17. Q-reeus Valued Senior Member

    Messages:
    3,052
    OK to consider such a situation, but note that Svidzinsky's theory, built from first principle postulates, does require quantized transverse components that allow GW's, and explains BB inflationary phase. Again, his reanalysis of LIGO/Virgo GW data looks set to confirm his vector theory. Always, we must let confirmed observation/experiment be the ultimate arbiter. As per my #1 post. I'm a fan of Mach's principle which on a natural reading allows no fixed background. However, it may still survive in a modified form even if his theory is finally confirmed correct. Time will tell.
     
  18. Hayden Registered Senior Member

    Messages:
    110
    Just a question. Suppose there is no singularity, which is highly unrealistic and non intuitive, in that scenario would the Gravitational Wave maths change? From the GR perspective pl.

    The black hole represents weird spacetime in GR, under such eventuality what exactly do we mean by black hole merging?
     
  19. Q-reeus Valued Senior Member

    Messages:
    3,052
    Not sure exactly what you mean by singularity re standard GR BH's. Any supposed singularity at r = 0 is wrt outside universe an event that in classical (no Hawking radiation etc.) GR only exists in the infinite future. In fact initially infalling matter just getting to the EH takes infinite time wrt external observers. I laugh at GR expert standard responses when such problems are posed. Which is that there is no problem because only the proper time of an infaller matters, and sans tidal destruction, such infaller sails past EH and on to 'singularity' in perfectly finite proper time. That the rest of the universe is infinitely old in just getting to the EH is side-stepped as merely an 'optical illusion' linked to extreme redshift.

    Anyway re GW's, in GR merger scenario 'singularities' play no part but merging of EH's does. It's all done using numerical methods given any realistic binary BH merger will have typically high individual BH spins at arbitrary initial relative orientations. Fierce maths with no hope of analytical solutions. LIGO site iirc will list papers going into the gory details. It has to be said that using such heavy number crunching based on GR, quite good agreement between theory and observation is had. At least if their 'template' system used for matching particular scenarios with detected events hasn't introduced biases that wrongly exclude alternate theories.
    A you know, Svidzinsky claims his theory has one big advantage wrt GR - much better fit to GW polarizations. This is still to be settled.
    The difficulties in justifying and explaining merger of two GR BH's, in a simplified non-spinning, non-orbiting, direct head-on merger, is set out here:
    http://www.mathpages.com/rr/s7-02/7-02.htm
    I don't buy it but it may satisfy you.

    Please Register or Log in to view the hidden image!

     
  20. Hayden Registered Senior Member

    Messages:
    110
    Contd from your links/comments in that infinity thread.

    With whatever I know of GR and metric theories, one thing is for sure that Einstein could associate the gravity with some kind of spacetime metric.

    People are free to inject their own ideas and fiddle with metric, would that not be an exercise in futile or at the best mathematical jugglery.

    By definition a suitable exponential function will not enter into infinities while a simple 1/r based function would, and maths can be created such that both the functions provide similar maths in limiting scenario; what does it mean? May be the common sense desire to pick the one which does not get into infinities! But dear sir, what is the meaning of a space or spacetime following exponential metric? Can you relate this with reality of the universe? What are you modelling with exponential metric and what reality it represents?
     
  21. Q-reeus Valued Senior Member

    Messages:
    3,052
    Stop right there. Are you saying that e.g. Yilmaz gravity or Svidzinsky vector gravity are nothing more than the result of folks 'fiddling with metric' with pure motivation to avoid infinities? Then you are making an unwarranted supposition. Why not go to the original source articles and find out how the theories were actually motivated and formed?
    Even if 'avoiding infinities' were a prime motivator, what matters is does the resulting theory cohere internally and agree with observation. Agreed?
    Understand I have no theory of my own. Merely looked for theories that were internally consistent and, as a welcome consequence, infinities never appear in such self-consistent theories. And btw did you actually study the material I linked to in both this thread and that other one? Because your response above here suggests not. If you have a deep commitment to GR as The Truth, just say so.
     
  22. Hayden Registered Senior Member

    Messages:
    110
    No, I do not have any deep commitment to GR, like many I may have some fondness to Newtonian, nothing more.

    My curiosity on this arose when you responded on that reality of infinity thread. What I am earnestly asking is to what this exponential metric relate to in reality. Exponential metric or for that matter any metric cannot be anything more than a mathematical abstraction, unless it is associated with some physical reality (or entity), and what is that reality? I am not hinting that it's your proposition, just asking since you appear to understand this better.
     
  23. Q-reeus Valued Senior Member

    Messages:
    3,052
    OK fine.
    GR's Schwarzschild metric: https://en.wikipedia.org/wiki/Schwarzschild_metric#Singularities_and_black_holes
    It unequivocally predicts an EH at perfectly finite r > 0 where time 'comes to a full stop' wrt outside observers. That's the GR time component of metric in action.
    For corresponding exponential metric, the exponential form guarantees time never stops wrt outside for any finite r > 0. No fundamental temporal divide that separates an exterior from an interior region.

    Apart from radial lengths going to zero wrt outside in Schwarzschild metric at EH where r > 0, vs finite values for all spatial components in exponential metric for all r > 0, the spatial metric components Schwarzschild vs e.g. Yilmaz metric, have a more subtle distinction that can be shown for a thin spherical mass shell. Basically, the former calls for an unphysical jump in the radial metric component in passing from outside to just inside the shell. Some think that issue can be avoided via a coordinate transformation but it can't. No such unphysical jump occurs for the exponential metric. Everything is smooth and reasonable. There is a further inconsistency re Schwarzschild metric in shell scenario that I won't expand on here.
    See above. The basic premise is that matter effects clocks and rulers as encapsulated in the notion of gravity as spacetime curvature. But not necessarily just spacetime curvature.
     
    Last edited: Jun 27, 2018

Share This Page