Fiber inflation and reheating

We present constraints on the reheating era within the string fiber inflation scenario, in terms of the effective equation-of-state parameter of the reheating fluid, wreh. The results of the analysis, completely independent on the details of the inflaton physics around the vacuum, illustrate the behavior of the number of e-foldings during the reheating stage, Nreh, and of the final reheating temperature, Treh, as functions of the scalar spectral index, ns. We analyze our results with respect to the current bounds given by the Planck mission data and to upcoming cosmological experiments. We find that large values of the equation-of-state parameter (wreh > 1/3) are particularly favored as the scalar spectral index is of the order of ns ∼ 0.9680, with a σns ∼ 0.002 error. Moreover, we compare the behavior of the general reheating functions Nreh and Treh in the fiber inflation scenario with the one extracted by the class of the α-attractor models with α = 2. We find that the corresponding reheating curves are very similar in the two cases.