Internal structure of non-Abelian black holes and nature of singularity

Abstract

Recent results concerning the internal structure of static spherically-symmetric non-Abelian black holes in the Einstein-Yang-Mills (EYM) theory and its generalizations including scalar fields are reviewed and discussed with an emphasis on the problem of a generic singularity in black holes. It is argued that in the theories admitting a violation of the naive no-hair conjecture the structure of singularity is essentially affected by the "hair roots". This invalidates an image of a non-Abelian black hole as a Schwarzschild black hole sitting inside the soliton. We give an analytic description of the generic oscillatory approach to the singularity in the pure EYM theory in terms of a divergent discrete sequence and show that the mass function is exponentially growing "in average". The second type of a generic approach to the singularity in hairy black holes is a "power-law mass inflation" which is realized in the theories including scalar fields. Both singularities are spacelike and no Cauchy horizons are met in the full interior region in conformity with the Strong Cosmic Censorship conjecture. Black holes violating this conjecture exist only for certain discrete values of the event horizon radius thus forming a subset of zero measure.