Brane inflation and trans-Planckian censorship conjecture

The constraint of trans-Planckian censorship conjecture on the brane inflation model is considered. The conjectures put an upper bound on the main parameter including temperature, inflation time, potential, and the tensor-to-scalar ratio parameter r. It is determined that the resulting constraint could be stronger than what we have for the standard inflationary models. The constraint, in general, depends on the brane tension and it is concluded that the conjecture also confined the value of brane tension to have consistency for the model. Confining the brane tension turns into a determining value for the five-dimensional Planck mass. The case of slowly varying Hubble parameter gives more interesting results for the epsilon and r, which indicates that the value of the tensor-to-scalar perturbation is not required to be extremely small.