  We discuss the dynamics of a (neutral) test particle in Topological Star
spacetime undergoing scattering processes by a superposed test radiation field,
a situation that in a 4D black hole spacetime is known as relativistic
Poynting-Robertson effect, paving the way for future studies involving
radiation-reaction effects. Furthermore, we study self-force-driven evolution
of a scalar field, perturbing the Top-Star spacetime with a scalar charge
current. The latter for simplicity is taken to be circular, equatorial and
geodetic. To perform this study, besides solving all the self-force related
problem (regularization of all divergences due to the self-field, mode sum
regularization, etc.), we had to adapt the 4D Mano-Suzuki-Takasugi formalism to
the present 5D situation. Finally, we have compared this formalism with the
(quantum) Seiberg-Witten formalism, both related to the solutions of a Heun
Confluent Equation, but appearing in different contexts in the literature,
black hole perturbation theory the first, quantum curves in super-Yang-Mills
theories the second.
