Stability of Palatini-f(R) cosmology

Understand

The evolution of linear cosmological perturbations in modified theories of gravity is investigated assuming the Palatini formalism.

• It has been discussed about the stability problem in this model based on the equivalence between f(R) gravity and the scalar tensor theory.
• However, we study this problem in the physical frame where the matter is minimally coupled.
• In general, the stability of the superhorizon metric evolution depends on models.