Vacuum axisymmetric gravitational collapse revisited: preliminary investigation

Abstract: Validating the results of [A.M. Abrahams and C.R. Evans, Phys. Rev. Lett. 70, 2980] poses a numerical challenge and has been inspiring a lot of research. We join these efforts and present our first steps to achieve this goal: we discuss a formulation of Einstein equations for a vacuum axisymmetric spacetime with vanishing twist in spherical-polar coordinates, its linearised approximation, and identify some problems in achieving numerically stable evolution at the threshold of a black hole formation.