UNIVERSALITY IN AXISYMMETRICAL VACUUM COLLAPSE

Evidence of universality is observed in the critical behavior of axisy mmetric vacuum gravitational collapse. The threshold of black hole for mation in the future development of time-antisymmetric initial data is found numerically and compared to previous results based on ingoing p ulses of gravitational waves. The power-law behavior of the black hole mass is again found near the critical point and the critical exponent value beta congruent-to 0.36 is consistent with our previous determin ation despite stark differences in the two sets of initial data. Simil ar evidence of universality is exhibited by the scaling factor DELTA o f the echoes in the gravitational field produced in the central region of collapse.