Strong lensing as a probe of braneworld

For the first time, we use the Event Horizon Telescope (EHT) data to constrain the parameters of braneworld black holes which constrain $\epsilon=0.0285^{+0.0888+0.1456}_{-0.0895-0.1475}$ for the anisotropic black hole and $q=-0.0305^{+0.1034+0.1953}_{-0.0895-0.1470}$ for the tidal Reissner-Nordstr$\ddot{o}$m (RN) black hole. Based on the fitted data and physical requirement, we calculate the photon deflection, the angular separation and time delay between different relativistic images of the anisotropic black hole and the tidal RN black hole in the ranges $-0.1190<\epsilon<0$ and $-0.1775 <q<0$. And furthermore, we study the quasinormal modes (QNMs) for the braneworld black holes. The results shed light on existence of extra dimension.