Static AdS Black Holes Surrounded by Strings and Quintessence-like Field within Rastall Gravity Framework

Abstract: In this work, we tested the physical properties of Rastall black holes in the presence of string clouds and quintessence. The modified spacetime geometry arising from the Rastall framework is first established, providing the basis for analyzing the geodesic structure. We study null geodesics in detail, testing photon trajectories, the conditions for photon spheres, BH shadows, the associated effective radial force, and the topological features of photon rings. Also, the analysis is further tested to timelike geodesics, where we investigate the motion of massive particles and determine the innermost stable circular orbits. In this case, we discuss the thermodynamic behavior of the system, show the effects of Rastall gravity, strings, and quintessence on the BHs stability and thermal characteristics. In this context, our results improve and show of how modifications to general relativity and surrounding matter distributions influence both the dynamical and thermodynamical aspects of BHs.