A note on inflationary scenario with non-minimal coupling
  We consider first order perturbation theory for a non-minimally coupled
inflaton field without assuming an adiabatic equation of state. In general
perturbations in non-minimally coupled theory may be non-adiabatic. However
under the slow-roll assumptions the perturbation theory may look like adiabatic
one. We show in the frame-work of perturbation theory, that our results of
spectral index and bound on no-minimal coupling parameter agree with the
results obtained using the adiabatic equation of state by the earlier authors.
