On cosmology in nonlinear multidimensional gravity with multiple factor spaces

Mar 13, 2018
7 pages
Published in:
  • Grav.Cosmol. 24 (2018) 2, 154-160
  • Published: Jun 6, 2018
e-Print:

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Abstract: (Springer)
Within the scope of multidimensional Kaluza–Klein gravity with nonlinear curvature terms and two spherical extra spaces of dimensions m and n, we study the properties of an effective action for the scale factors of extra dimensions. Dimensional reduction leads to an effective 4D multiscalar-tensor theory. Based on qualitative estimates of the Casimir energy contribution at a physically reasonable length scale, we demonstrate the existence of such sets of the initial parameters of the theory in the case m = n that provide a minimum of the effective potential at this scale which yields a fine-tuned value of the effective 4D cosmological constant The corresponding size of extra dimensions depends of which conformal frame is interpreted as the observational one: it is about three orders of magnitude larger than the standard Planck length if we adhere to the Einstein frame, but it is n-dependent in the Jordan frame, and its invisibility requirement restricts the total dimension to values D = 4 + 2n ≤ 20.
Note:
  • 8 pages, 2 figures
  • gravitation: higher-dimensional
  • energy: Casimir
  • gravitation: nonlinear
  • dimensional reduction
  • cosmological constant
  • effective potential
  • cosmological model
  • effective action
  • curvature
  • transformation: conformal