Geometric creation of quantum vorticity
  We consider superfluidity and quantum vorticity in rotating spacetimes. The system is described by a complex scalar satisfying a nonlinear Klein-Gordon equation. Rotation terms are identified and found to lead to the transfer of angular momentum of the spacetime to the scalar field. The scalar field responds by rotating, physically behaving as a superfluid, through the creation of quantized vortices. We demonstrate the vortex nucleation through numerical simulation. 
Michael R.R. Good, Chi Xiong, Alvin J.K. Chua, Kerson Huang
gr-qc astro-ph.HE hep-th