Thermodynamic geometry for a non-extensive ideal gas

TL;DR

This paper introduces a generalized entropy for an ideal gas within superstatistics, analyzes its thermodynamic geometry, and finds that it induces effective interactions without phase transitions, relevant for small or confined systems.

Contribution

It derives a new generalized entropy for an ideal gas and explores its thermodynamic geometric properties, revealing effective interactions in non-extensive systems.

Findings

Generalized entropy induces effective interactions

No phase transition occurs with the new entropy

Potential applications in small or confined systems

Abstract

A generalized entropy arising in the context of superstatistics is obtained for an ideal gas. The curvature scalar associated to the thermodynamic space generated by this modified entropy is calculated using two formalisms of the geometric approach to thermodynamics. Using the curvature/interaction hypothesis of the geometric approach to thermodynamic geometry it is found that as a consequence of considering a generalized statistics, an effective interaction arises but the interaction is not enough to give a phase transition. This generalized entropy seems to be relevant in confinement or in systems with not so many degrees of freedom, so it could be interesting to use such entropies to characterize the thermodynamics of small systems.