Transplanckian inflation as gravity echoes
  In this work, we show that, in the presence of non-minimal coupling to
gravity, it is possible to generate sizeable tensor modes in single-field
models without transplanckian field values. These transplanckian field values
apparently needed in Einstein gravity to accommodate the experimental results
may only be due to our insistence of imposing a minimal coupling of the
inflaton field to gravity in a model with non-minimal couplings. We present
three simple single-field models that prove that it is possible accommodate a
large tensor-to-scalar ratio without requiring transplanckian field values
within the slow-roll regime.
