Supersymmetric Superconducting Bag as a Core of Kerr Spinning Particle
  The problem of a regular matter source for the Kerr spinning particle is discussed. A class of minimal deformations of the Kerr-Newman solution is considered obeying the conditions of regularity and smoothness for the metric and its matter source.   It is shown that for charged source corresponding matter forms a rotating bag-like core having (A)dS interior and smooth domain wall boundary. Similarly, the requirement of regularity of the Kerr-Newman electromagnetic field leads to superconducting properties of the core.   We further consider the U(I) x U'(I) field model (which was used by Witten to describe cosmic superconducting strings), and we show that it can be adapted for description of superconducting bags having a long range external electromagnetic field and another gauge field confined inside the bag. Supersymmetric version of the Witten field model given by Morris is analyzed, and corresponding BPS domain wall solution interpolating between the outer and internal supersymmetric vacua is considered. The charged bag bounded by this BPS domain wall represents an `ultra-extreme' state with a total mass which is lower than BPS bound of the wall. It is also shown that supergravity suggests the AdS vacuum state inside the bag.   Peculiarities of this model for the rotating bag-like source of the Kerr-Newman geometry are discussed. 
Alexander Burinskii