Aspects of cosmological expansion in F(R) gravity models

Understand

We study cosmological expansion in F(R) gravity using the trace of the field equations.

• High frequency oscillations in the Ricci scalar, whose amplitude increase as one evolves backward in time, have been predicted in recent works.
• We show that the approximations used to derive this result very quickly breakdown in any realistic model due to the non-linear nature of the underlying problem.
• Using a combination of numerical and semi-analytic techniques, we study a range of models which are otherwise devoid of known pathologies.