Nonzero Spatial Curvature in Symmetric Teleparallel Cosmology

Understand

We consider the symmetric teleparallel $f\left( Q\right) $-gravity in Friedmann--Lema\^{\i}tre--Robertson--Walker cosmology with nonzero spatial curvature.

• For a nonlinear $f\left( Q\right) $ model there exist always the limit of General\ Relativity with or without the cosmological constant term.
• The de Sitter solution is always provided by the theory and for the specific models $f_{A}\left( Q\right) \simeq Q^{\frac{\alpha}{\alpha-1}}% ~,~f_{B}\left( Q\right) \simeq Q+f_{1}Q^{\frac{\alpha}{\alpha-1}}$ and $f_{C}\left( Q\right) \simeq Q+f_{1}Q\ln Q$ it was found to be the unique attractor.
• Consequently small deviations from STGR can solve the flatness problem and lead to a de Sitter expansion without introduce a cosmological constant term.