Black hole shadows in accelerating Kerr–Newman–Taub–NUT and Braneworld spacetimes

Abstract

We investigate the null geodesic structure and corresponding black hole shadows in the accelerating Kerr–Newman–Taub–NUT (AKNTN) spacetime-a highly generalized solution that incorporates rotation, electric charge, acceleration, and NUT charge. By deriving a separable Hamilton–Jacobi equation for null test particles, we demonstrate that the additional parameters enable equatorial circular photon orbits, a feature absent in generic accelerating spacetimes. Building on this framework, we analyze the influence of acceleration, spin, electric (or tidal) charge, and NUT parameters on the shadow observables, such as the shadow radius and distortion. Furthermore, we extend our study to include tidal charged black holes in the RS-II braneworld scenario by replacing the electric charge parameter with a tidal charge, \(\mathcal {Q}\), which may assume either sign. Our numerical results reveal that increasing the acceleration parameter compresses the photon capture region and reduces the shadow size, while a negative tidal charge deepens the gravitational potential, enlarging the shadow. These findings offer new insights into the interplay between extra-dimensional effects and classical gravitational parameters, with potential implications for future astrophysical observations.