  This paper studies the normalizability criterion for the one-loop wave
function of the universe in a de Sitter background, when various unified gauge
models are considered. It turns out that, in the absence of interaction between
inflaton field and other matter fields, the supersymmetric version of such
unified models is preferred. By contrast, the interaction of inflaton and
matter fields, jointly with the request of normalizability at one-loop order,
picks out non-supersymmetric versions of unified gauge models.
