Mathematica codes
You need package files to run Mathematica codes below.
package files : Gravity.m Gravity2.m GravityPt.m
Mathematica codes for each section or appendix.
Tensor perturbations in sec. 3 and app. A: TensorPt.nb TensorPt2.nb
Numerical plots in sec. 4 : TensorPt3.nb
Effective action for tensor perturbations in app. B : TensorPtAct.nb