Maham MuzaffarFA23-RMT-018Dr. Abdul JawadLHR TP 97652026-01-062025https://repository.cuilahore.edu.pk/handle/123456789/240In this thesis, we study the thermodynamics and stability of five-dimensional Schwarzschild AdS black hole by using the modified entropy. We analyze the stability and phase tran sitions with the help of modified entropy and calculate thermodynamic quantities such as mass, temperature, Gibbs free energy, chemical potential, and heat capacities. As modified entropy, we use a three parameter entropy which straightforwardly meets all the conditions like the monotonically increasing function, the generalized third law, and Bekenstein-Hawking limit. Using this three parameter entropy along with five-dimensional Schwarzschild AdS black hole, we examine the thermodynamical geometries like Wein hold, Ruppineir and Quevedo geometries through their curvature scalars. Finally, we also f ind the sparsity index to check the unusual nature of Hawking radiation emission from black holes.enDr. Abdul JawadMATHEMATICSBlack Hole ThermodynamicsThesis