A Solution to the Polonyi Problem in the Minimum SUSY-GUT
  We show that the Polonyi problem is solved in the minimum SUSY-GUT model in which a self-coupling strength for a heavy Higgs $\Sigma$, $\lambda\Sigma^{3}$, is very small $\lambda\sim 10^{-6}$. It is stressed that with this small $\lambda$ the mass of the physical $\Sigma$ becomes $m_{\Sigma} \sim 10^{12}\GEV$ and the unification scale is raised up to the gravitational one, $M\simeq 2\times 10^{18}\GEV$. A potential problem, however, is also pointed out in this GUT model. 
T. Moroi and T. Yanagida