Generating Entangled Inflationary Quantum States
  Entangled inflationary quantum states offer an interesting alternative to the
standard Bunch-Davies vacuum. While they can be viewed from the point of view
of a theory of effective initial states, it has been unclear exactly how such
states might be generated. Using a model involving two scalar fields
$\Phi,\Sigma$ we show that if {\em both} fields have non-zero time dependent
expectation values $\phi,\sigma$ respectively, and if the interaction potential
$V(\Phi,\Sigma)$ when evaluated at these expectation values has
$\partial_{\phi}\partial_{\sigma}V(\phi, \sigma)\neq 0$, this can serve as a
source term for the entanglement kernel describing the state within the
Gaussian approximation around the expectation values. We also show how cubic
interactions between the metric perturbation $\zeta$ and a scalar $\Sigma$ can
be used to generate a source term for entanglement.
