Physica Scripta, vol.98, no.2, 2023 (SCI-Expanded)
© 2023 IOP Publishing Ltd.Our primary goal in this paper is to confirm new universal relations in black hole thermodynamics. We investigate the universal relations by selecting different black holes. First, we obtain the black holes thermodynamic relations assuming a new minor correction is added to the AdS part of the action. Then we confirm the universal relations by performing a series of direct calculations. It is noteworthy that according to each of the properties related to black holes, a new universal relation can be obtained according to this method. We confirm two different types of these universal relations for various black holes. Furthermore, we also consider black holes in AdS space surrounded by perfect fluid. We use a small correction to the action and obtain the modified thermodynamic quantities. We achieve two new universal relations which correspond to the parameters of perfect fluid and magnetic charge of the Bardeen AdS Black Hole. Finally, the new universal relation leads us to understand the charge-to-mass ratio, i.e., weak gravity conjecture like behavior. We also find that the weak gravity conjecture condition is satisfied for the black hole surrounded by perfect fluid.