De Sitter Cosmic Strings and Supersymmetry
  We study massive spinor fields in the geometry of a straight cosmic string in a de Sitter background. We find a hidden N=2 supersymmetry in the fermionic solutions of the equations of motion. We connect the zero mode solutions to the heat-kernel regularized Witten index of the supersymmetric algebra. 
V. K. Oikonomou
hep-th gr-qc math-ph math.MP