Primordial gravitational waves and the collapse of the wave function
  "The self-induced collapse hypothesis" was introduced by D. Sudarsky and
collaborators to explain the origin of cosmic structure from a perfect
isotropic and homogeneous universe during the inflationary regime. In this
paper, we calculate the power spectrum for the tensor modes, within the
semiclassical gravity approximation, with the additional hypothesis of a
generic self-induced collapse of the inflaton's wave function; we also compute
an estimate for the tensor-to-scalar ratio. Based on this calculation, we show
that the considered proposal exhibits a strong suppression of the tensor modes
amplitude; nevertheless, the corresponding amplitude is still consistent with
the joint BICEP/KECK and Planck Collaboration's limit on the tensor-to-scalar
ratio.
