The evolutions of the innermost stable circular orbits in dynamical spacetimes

In this paper, we studied the evolutions of innermost stable circular orbits (ISCOs) in dynamical spacetimes. At first, reviewed method to obtain ISCO Schwarzschild spacetime by varying its conserved orbital angular momentum. Then, demonstrated is equivalent effective potential general static and stationary Unlike method, which depends on presence energy, requires existence momentum spacetime. So it can be easily generalized spacetimes where there exists From generalization, ISCOs Vaidya spacetime, Vaidya-AdS slow rotation limit Kerr-Vaidya The results given these examples are all reasonable compared with photon spheres