Local gravity test of unified models of inflation and dark energy in \(f(R)\) gravity

We consider \(f(R)\) gravity theories which unify \(R^n\) inflation and dark energy models. First, from the final Planck data of the cosmic microwave background, we obtain a condition, \(1.977 < n < 2.003\). Next, under this constraint, we investigate local-gravity tests for three models. We find that the \(R^n\) term can dominate over the dark energy term even at the Earth's curvature scale, contrary to intuition; however, the \(R^n\) term does not relax or tighten the constraints on the three models.