Joule–Thomson expansion of Hayward-AdS black hole surrounded by fluid of strings

In this work, we investigate the Joule–Thomson expansion of a regular Hayward-AdS black hole surrounded by a fluid of strings. We analyze the behavior of the Joule–Thomson coefficient ${\mu }_J$, the inversion temperature $T_i$, and isenthalpic curves to understand the impact of key parameters such as the Hayward parameter $\Theta$ and the fluid of string parameters $b,\beta$ on black hole thermodynamics. Our results reveal that the presence of the string fluid significantly modifies the black hole’s cooling-heating transition, shifting the inversion curves and altering the phase transition structure. The inversion temperature increases with higher values of $\beta$, indicating that the fluid of strings parameter enhances the cooling capacity of the black hole. Similarly, variations in $\Theta$ and $b$ affect the inversion pressure and temperature, showing that quantum gravity-inspired modifications introduce new thermodynamic properties absent in standard AdS black holes. The graphical analysis of the $T-P$ plane further illustrates the deviations in isenthalpic curves, demonstrating the influence of mass and external string interactions on black hole thermodynamics. These findings provide deeper insights into the thermodynamic behavior of regular black holes and their possible connections to quantum gravity. Our study contributes to the broader understanding of black hole phase transitions in modified gravity scenarios. It suggests potential avenues for future research on entropy corrections and the observational implications of these modified thermodynamic behaviors.