Revisiting f(R) gravity's rainbow: Inflation and primordial fluctuations

Abstract

Abstract We study inflation and the generation of primordial fluctuations in f(R) gravity's rainbow. We calculate the cosmological perturbations and then the scalar and tensor primordial power spectrum. We contrast the predictions of the model with the current observational data from PLANCK and BICEP/Keck. Particularly, we found new results for the scalar spectral index ns and the tensor-to-scalar ratio r along with new observational constraints on the rainbow functions.