A set of six square roots of homogeneouss in four variables, related to a binary system of black holes

A Calabi-Yau threefold coming from two black holes

We show that a set of six square roots of homogeneous polynomials in four variables, related to a binary system of black holesstudied by stefan weinzierl, is not rationalizable.We prove it by showing that the variety associated to the product of four of the six square roots is not unirational.In particular, we show that the smooth model of is a calabi-yau threefold.