Stable exponential cosmological solutions with two factor spaces in the Einstein–Gauss–Bonnet model with a Λ -term

We study D-dimensional Einstein–Gauss–Bonnet gravitational model including the Gauss–Bonnet term and the cosmological term Λ. We find a class of solutions with exponential time dependence of two scale factors, governed by two Hubble-like parameters H> 0 and h, corresponding to factor spaces of dimensions m> 2 and l> 2 , respectively. These solutions contain a fine-tuned Λ = Λ (x, m, l, α) , which depends upon the ratio h/ H= x, dimensions of factor spaces m and l, and the ratio α= α2/ α1 of two constants (α2 and α1) of the model. The master equation Λ (x, m, l, α) = Λ is equivalent to a polynomial equation of either fourth or third order and may be solved in radicals. The explicit solution for m= l is presented in “Appendix”. Imposing certain restrictions on x, we prove the stability of the solutions in a class of cosmological solutions with diagonal metrics. We also consider a subclass of solutions with small enough variation of the effective gravitational constant G and show the stability of all solutions from this subclass. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Authors
Number of issue
10
Language
English
Status
Published
Number
119
Volume
50
Year
2018
Organizations
  • 1 Institute of Gravitation and Cosmology, Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St., Moscow, 117198, Russian Federation
  • 2 Center for Gravitation and Fundamental Metrology, VNIIMS, 46 Ozyornaya ul., Moscow, 119361, Russian Federation
  • 3 Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Troitsk, 142190, Russian Federation
Keywords
Cosmology; Gauss-Bonnet; Variation of G
Date of creation
19.10.2018
Date of change
19.10.2018
Short link
https://repository.rudn.ru/en/records/article/record/6404/