Deformations of elliptic Calabi--Yau manifolds
  The aim of this note is to investigate characterizations and deformations of elliptic Calabi--Yau manifolds, building on earlier works of Wilson and Oguiso. Version 2: References updated and small changes. Version 3: Smoothness conditions removed from several theorems, plus some reorganization. Version 4: Several references added. 
J\'anos Koll\'ar (Princeton Univ)
math.AG hep-th