Recent content by torsten

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    A Physical meaning of "exotic smoothness" in (and only in) 4D

    No special relativity is not effected. This local splitting is equivalent to the existence of a Lorentz structure at a manifold (a globally non-vanishing vector field). But more is true in the exotic context: exotic smoothness admit locally hyperbolic structures and the isometry of the 3D...
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    A Physical meaning of "exotic smoothness" in (and only in) 4D

    Now I found some rest to answer this question: how does this space looks like? For simplicity I will concentrate on exotic versions of S3×ℝ. For the exotic space, there is no splitting into space and time globally. Therefore, there is no global, smooth S3 for a fixed time. If one wants to...
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    A Physical meaning of "exotic smoothness" in (and only in) 4D

    I will start only with a little overview what was done in the last 6 or 7 years. The informations above are a little bit outdated... But at first let me state that nearly all 4-dimensional manifolds admit exotic differential structures. For compact 4-manifolds there are countable infinite many...
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    Papers that combine LQG with twistor theory

    In my opinion, twisted geometries will give a better semi-classical limit. The problem is viewable in perturbative quantum gravity. Every graviton gives only a (in principle) beglectable contribution and you need uncountable infinite many gravitons to get measurable contribution. Regge calculus...
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    Papers that combine LQG with twistor theory

    I agree with marcus: I can only describe my own view. A real evaluation is not possible, even experimental verifications are missed. But back to twisted geometries: I want to compare it with the two approaches to geometry: Riemann or Cartan. The discrete version of Riemannian geometry is Regge...
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    Papers that combine LQG with twistor theory

    As far as I know the motivations are different: Witten found twistor-like relations between string amplitudes. With the help of these ideas, some people were able to express loop amplitudes in some QFT (mostly supersymmetric) by tree amplitudes. As I explained above, the LQG use of twistor...
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    Papers that combine LQG with twistor theory

    Twistor theory was originally designed to obtain an effective spinor representation of the conformal group SO(4,2) of the Minkowski space, i.e. the representation of SU(2,2). All constructions work only for the flat Minkowski space and Penrose (around 1976) tried to extend it to the curved...
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    Phase transition at high energies?

    Some theories (like causal triangulations) obtained a phase transition from 4D to 2D. Maybe you had this in mind?
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    String theory deviations from GR in strong field regime

    The usual process to generate gravitational waves is part of classical GRT. Currently there is no contribution of quantum gravity to this part. Therefore sring theory is also not able to produce any contribution to this topic. As far as I know scalar-tensor theories do not produce a different...
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    Can the universe become stable with a new electroweak vacuum

    Because of this article: http://physics.aps.org/articles/v8/108 it is for me more likely that the vacuum tends to the stable region. But one needs more data especially to determine the Higgs potential. See also http://arxiv.org/abs/1507.08833
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    Exploring Manifolds Beyond Spacetime: Unification Programs in Quantum Gravity

    One possible research program is the Causal set theory of Rafael Sorkin and co-workers. But it seems you look for another representation of quantum theory? In that case check out the approaches using model (or topos) theory especially forcing. Interesting for you is maybe also my own approach...
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    Loop-and-allied QG bibliography

    http://arxiv.org/abs/1601.06436 Smooth quantum gravity: Exotic smoothness and Quantum gravity Torsten Asselmeyer-Maluga (Submitted on 24 Jan 2016) Over the last two decades, many unexpected relations between exotic smoothness, e.g. exotic R4, and quantum field theory were found. Some of these...
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    Thoughts on Quantum Holonomy Theory?

    Because of this discussion, I had a chance to look into this paper. In principle, kodama above is right: it is a combination of NCG and LQG to get better control about the limit. But it is also much more. Originally, the work started with the construction of the spectral triple some years ago...
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    Is Space-Time a Continuum or a Physical Object?

    In principle I agree with: the discrete spektra is the most important point, see the smooth Schrödinger equation. I also agree that the point is not fundamental in GR. If I remember correctly, it is the famous hole argument of Einstein (see http://plato.stanford.edu/entries/spacetime-holearg/)...
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    Is Space-Time a Continuum or a Physical Object?

    For me, it is a dogma that the spacetime in quantum gravity has to be discrete. As far as I know, there is no experiment showing the discreteness. It is interesting that a smooth manifold has much to do with discrete structures. I will only mention a few one: (for more details, see my essay at...
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