Accretion onto topological dyonic dilaton black hole.

The process by which a massive object accumulates matter, known as accretion, is a key mechanism for understanding the energetic dynamics of dark compact objects, such as BHs. Gravitational energy is transformed into radiation as material falls inward, making accretion a vital process. In this paper, we delve into the motion of test particles around a topological dyonic dilaton BH, focusing on the innermost stable circular orbit (ISCO) and its dependency on the dilaton field and BH topology. Additionally, we investigate the accretion of a perfect fluid onto a spherically symmetric black hole, providing detailed analytical expressions for the four-velocity and proper energy density of the accreting fluid. Our findings reveal that both the dilaton field and the BHs topology exert substantial influence on the motion of test particles, directly impacting the accretion process. Notably, we observe that as the dilaton field and topological parameters increase, the ISCO radius expands, while the energy flux decreases. Moreover, the energy density and radial component of the four-velocity of the infalling fluid diminish near the central source. These results provide deeper insights into the role of BH topology and dilaton fields in shaping accretion dynamics, offering new pathways for exploring modified gravity theories. [ABSTRACT FROM AUTHOR]