On the exact solutions of the Bianchi IX cosmological model in the   proper time
  It has recently been argued that there might exist a four-parameter analytic solution to the Bianchi IX cosmological model, which would extend the three-parameter solution of Belinskii et al. to one more arbitrary constant. We perform the perturbative Painlev\'e test in the proper time variable, and confirm the possible existence of such an extension. 
J. Springael (VUB Brussels), R. Conte (CEA Saclay), M. Musette (VUB   Brussels)