Circular geodesics in tidal-charged black hole

Abstract

We study the existence and stability criteria for circular geodesics of spherically symmetric tidal-charged black hole (BH). We investigate in details the equatorial causal geodesics of the tidal-charged BH in comparison with spherically symmetric Reissner–Nordström BH spacetime. We particularly focused on both the null circular geodesics and time-like circular geodesics. Using the effective potential diagram, we have compared the geodesic structure between two spacetimes. We have derived the ISCO (innermost stable circular orbit), MBCO (marginally bound circular orbit) and CPO (circular photon orbit) for both the spacetimes. Moreover, we have derived the quasi-normal modes[Formula: see text]QNMs[Formula: see text] frequency in the eikonal limit for both the spacetimes via Lyapunov exponent. In the appendix section, we have shown that a spherically symmetric tidal-charged BH can act as particle accelerators with ultra-high center-of-mass (CM) energy in the limiting case of maximal BH tidal-charge[Formula: see text] and it is possible when two neutral particles are colliding near the horizon.