Periodic Orbits Around Kerr Sen Black Holes*

Chang-Qing Liu,Chi-Kun Ding,Ji-Liang Jing

Fig. 2 (Color online) Effective potentials with different the charge parameter $b$ for the corresponding angular momentum $L=L_{\rm av}=({L_{\rm ISCO}+L_{\rm IBCO}})/{2}$ in the Kerr Sen black hole: in (a), parameter takes the value $b=0, 0.2, 0.4, 0.6, 0.8, 1$ from top to bottom; in (b),parameter takes the value $b=0.69, 0.6, 0.4, 0.2, 0$ from left to right. Here we set $M=1$.