A solution to the Baer splitting problem
  Let R be a commutative domain. We prove that an R-module B is projective if and only if Ext^1(B,T)=0 for any torsion module T. This answers in the affirmative a question raised by Kaplansky in 1962. 
Lidia Angeleri H\"ugel (Universit\`a dell' Insubria) Silvana Bazzoni   (Universit\`a di Padova) Dolors Herbera (Universitat ...