  We investigate the massless $\lambda \phi^4$ theory in de~Sitter space. It is
unnatural to assume a minimally coupled interacting scalar field, since $\xi=0$
is not a fixed point of the renormalization group once interactions are
included. In fact, the only case where perturbation theory can be trusted is
when the field is non-minimally coupled at the minimum of the effective
potential. Thus, in perturbation theory, there is no infrared divergence
associated with this scalar field.
