A case for kinetically dominated initial conditions for inflation

Understand

We make a case for setting initial conditions for inflation at the Planck epoch in the kinetically dominated regime.

• For inflationary potentials with a plateau or a hill, i.e.
• potentials that are bounded from above within a certain region of interest, we cannot claim complete ignorance of the energy distribution between kinetic and potential energy, and equipartition of energy at the Planck epoch becomes questionable.
• We analyse different classes of potentials in phase-space and quantify the fraction of the Planck surface that is kinetically dominated.