Unified Gauge Models and One-Loop Quantum Cosmology
  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. 
Giampiero Esposito, Alexander Yu. Kamenshchik and Gennaro Miele