Confronting Kähler moduli inflation with CMB data

In models of inflation obtained from string compactification, moduli vacuum misalignment leads to an epoch in the postinflationary history of the Universe when the energy density is dominated by cold moduli particles. This effect leads to a modification in the number of e -foldings (N_pivot) between the horizon exit of the CMB modes and the end of inflation. Taking Kähler moduli inflation as a prototype, the shift in e -foldings turns out to be a function of the model parameters which also determines the inflationary observables. We analyze this scenario numerically using publicly available ModeChord and CosmoMC with the latest Planck+BICEP2/Keck array data to constrain the model parameters and N_pivot. In light of the present and future precision data, the results show the importance of the careful consideration of any postinflationary nonstandard epoch, as well as the effects of reheating.