Linear stability analysis of a rotating thin-shell wormhole

We cut and paste two Banados-Teitelboim-Zanelli (BTZ) spacetimes at a throat by the Darmois-Israel method to construct a rotating wormhole with a thin shell filled with a barotropic fluid. The thin shell at the throat and both sides of the throat corotate. We investigate the linear stability of the thin shell of the rotating wormhole against radial perturbations. We show that the wormhole becomes more and more stable the larger its angular momentum is until the angular momentum reaches a critical value and that the behavior of a condition for stability significantly changes when the angular momentum exceeds the critical value. We find that the overcritical rotating wormhole has the radius of the thin shell, which is stable regardless of the equation of state for the barotropic fluid.
Comment: 8 pages, 3 figures, title changed, minor correction, references added, accepted for publication in Physical Review D