Angular momentum at the black hole threshold

Near the black hole threshold in phase space, the black hole mass as a function of the initial data shows the "critical scaling" M \simeq C (p-p_*)^\gamma, where p labels a family of initial data, p_* is the value of p at the threshold, and the critical exponent \gamma is universal for a given matter model. The black hole charge Q obeys a similar law. To complete the picture, we include angular momentum as a perturbation. For the black hole angular momentum \vec L we find the oscillating behavior \vec L \simeq Re[ (\vec A + i \vec B) (p-p_*)^{\mu+i\omega} ]. The assumptions of the calculation hold for p = \rho / 3 perfect fluid matter, and we calculate \mu \simeq 0.799 and \omega \simeq 0.231.