%0 Journal Article %T On almost holomorphic Lagrangian fibrations %A Daisuke Matsushita %J Mathematics %D 2012 %I arXiv %X We prove that the pull back of an ample line bundle by an almost holomorphic Lagrangian fibration is nef. As an application, we show birational semi rigidity of Lagrangian fibrations. %U http://arxiv.org/abs/1209.1194v1