Gravitational waves and large field inflation
  According to the famous Lyth bound, one can confirm large field inflation by
finding tensor modes with sufficiently large tensor-to-scalar ratio $r$. Here
we will try to answer two related questions: Is it possible to rule out all
large field inflationary models by not finding tensor modes with $r$ above some
critical value, and what can we say about the scale of inflation by measuring
$r$? However, in order to answer these questions one should distinguish between
two different definitions of the large field inflation and three different
definitions of the scale of inflation. We will examine these issues using the
theory of cosmological $\alpha$-attractors as a convenient testing ground.
