Document Type : Regular article

Authors

• Saheb Soroushfar ¹
• Sayyed Mehrab Ramezani ²

¹ Department of Physics, College of Sciences, Yasouj University, 75918-74934 Yasouj, Iran

² Department of Mathematics, Yasouj University,‎ Yasouj, Iran‎.

Abstract

We investigate the Joule Thomson expansion of a symmergent black hole within an extended phase-space formalism in which the thermodynamic pressure is introduced as an independent variable. The symmergent entropy contains the parameter \(\hat{\alpha}\), which modifies the enthalpy and thermodynamic volume relative to their standard forms. We show that the Joule Thomson coefficient depends only on the combination \(8\pi P r_{+}^{2}\), leading to an inversion curve \(P_{\mathrm{i}} = \frac{\pi}{2} T_{\mathrm{i}}^{2}\) that is independent of \(\hat{\alpha}\). The isenthalpic curves, however, retain a parametric dependence on \(\hat{\alpha}\), indicating that the symmergent sector affects the thermodynamic trajectories but not the inversion boundary itself. The inversion pressure and temperature are derived explicitly, and the cooling regime \(P < P_{\mathrm{i}}\) is distinguished from the heating regime \(P > P_{\mathrm{i}}\).‏‎
Since the effective geometry is asymptotically AdS-like for positive pressure, the results also admit a holographic reading, in which the Joule Thomson expansion corresponds to an isenthalpic process in the dual field theory.
The results provide a consistent thermodynamic framework for symmergent black holes and clarify the role of the symmergent parameters in the Joule Thomson process.

Keywords

• Symmergent gravity
• Black hole thermodynamics
• ‎Joule ‎Thomson expansion
• Extended phase space
• Inversion curve
• Isenthalpic process‎

Main Subjects

• Physics