On the geometry of the Hawking Turok instanton
  We discuss the coordinate complexification necessary to obtain a spatially homogeneous open universe in the singular instantonic solution recently suggested by Hawking and Turok (hep-th/9802030), concluding that only the time coordinate $\sigma$ of the spatially inhomogeneous De Sitter-like Lorentzian solution and its scale factor should be rotated in order to continue into a Lorentzian open universe. 
Pedro F. Gonzalez-Diaz (IMAFF, CSIC)