A Scale at 10 MeV, Gravitational Topological Vacuum, and Large Extra Dimensions

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UNIVERSE, vol.4, no.7, 2018 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 4 Issue: 7
  • Publication Date: 2018
  • Doi Number: 10.3390/universe4070080
  • Journal Name: UNIVERSE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: MacDowell-Mansouri formalism, Bjorken-Zeldovich scale, Gauss-Bonnet term, Einstein-Cartan formalism, Big Bang nucleosynthesis, cosmological constant, Kodama wavefunctions, COSMOLOGICAL CONSTANT, E(+)E(-) PAIRS, FIELD-THEORY, TRANSITION, MASS, SUPERCONNECTIONS, MILLIMETER, GRAVITY, RANGE, FORCE
  • Middle East Technical University Affiliated: No


We discuss a possible scale of gravitational origin at around 10 MeV, or 10 12 cm, which arises in theMacDowell-Mansouri formalism of gravity due to the topological Gauss-Bonnet term in the action, as pointed out by Bjorken several years ago. A length scale of the same size emerges also in the Kodama solution in gravity, which is known to be closely related to theMacDowell-Mansouri formulation. We particularly draw attention to the intriguing incident that the existence of six compact extra dimensions originated from TeV-scale quantum gravity as well points to a length scale of 10 12 cm, as the compactification scale. The presence of six such extra dimensions is also in remarkable consistency with theMacDowell-Mansouri formalism; it provides a possible explanation for the factor of similar to 10120 multiplying the Gauss-Bonnet term in the action. We also comment on the relevant implications of such a scale regarding the thermal history of the universe motivated by the fact that it is considerably close to 1-2MeV below which the weak interactions freeze out, leading to Big Bang Nucleosynthesis.