Trans-Planckian censorship and inflationary cosmology
Alek Bedroya, Robert Brandenberger, Marilena Loverde, Cumrun Vafa
Abstract
We study the implications of the recently proposed Trans-Planckian censorship conjecture (TCC) for early Universe cosmology and in particular inflationary cosmology. The TCC leads to the conclusion that if we want inflationary cosmology to provide a successful scenario for cosmological structure formation, the energy scale of inflation has to be lower than ${10}^{9}\text{ }\text{ }\mathrm{GeV}$. Demanding the correct amplitude of the cosmological perturbations then forces the generalized slow-roll parameter $\ensuremath{\epsilon}$ of the model to be very small ($<{10}^{\ensuremath{-}31}$). This leads to the prediction of a negligible amplitude of primordial gravitational waves. For slow-roll inflation models, it also leads to severe fine-tuning of initial conditions.