• Source: World crystal

      • The world crystal is a theoretical model in cosmology which provides an alternative understanding of gravity proposed by Hagen Kleinert in line with induced gravity.


      Overview


      Theoretical models of the universe are valid only at large distances. The properties of spacetime at ultrashort distances of the order of the Planck length are completely unknown since they have not been explored by any experiment. At present, there are various approaches that try to predict what happens at these distances, such as Quantum Gravity.
      The World Crystal model is an alternative which exploits the fact that crystals with defects have the same non-Euclidean geometry as spaces with curvature and torsion. Thus the world crystal represents a model for emergent or induced gravity in an Einstein–Cartan theory of gravitation (which embraces Einstein's theory of General Relativity). The model illustrates that the world may have, at Planck distances, quite different properties from those predicted by string theorists. In this model, matter creates defects in spacetime which generate curvature and all the effects of general relativity.
      The existence of a shortest length at the Planck level has interesting consequences for quantum physics at ultrahigh energies. For example, the uncertainty relation
      will be modified. The World Crystal implies specific modifications.


      See also


      Quantum cosmology
      String cosmology
      Brane cosmology
      Loop quantum cosmology
      Top-down cosmology
      Non-standard cosmology


      References




      Literature


      Kleinert, H. (2008). Multivalued Fields in Condensed Matter, Electrodynamics, and Gravitation (PDF). World Scientific. pp. 338ff. ISBN 978-981-279-170-2.
      Danielewski, M. (2005). "Defects and Diffusion in the Planck-Kleinert Crystal: The Matter, Gravity, and Electromagnetism" (PDF). Proceedings of the 1st International Conference on Diffusion in Solids and Liquids.
      Kleinert, H.; Zaanen, J. (2004). "World Nematic Crystal Model of Gravity Explaining the Absence of Torsion". Physics Letters A. 324 (5–6): 361–365. arXiv:gr-qc/0307033. Bibcode:2004PhLA..324..361K. doi:10.1016/j.physleta.2004.03.048.
      t' Hooft, G. (2008). "Crystalline Gravity" (PDF). Erice Lectures 2008.

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