%0 Journal Article %T A representation formula for indefinite improper affine spheres %A Daisuke Nakajo %J Mathematics %D 2008 %I arXiv %X We construct a new representation formula for indefinite improper affine spheres in terms of two para-holomorphic functions and study singularities which appear in this representation formula. As a result, it follows that cuspidal cross caps never appear as the singularities on indefinite improper affine spheres and so on. Comparison with other representation formulae are also studied. %U http://arxiv.org/abs/0801.4832v1