Thermodynamic curvature and ensemble nonequivalence

Understand

In this work we consider thermodynamic geometries defined as Hessians of different potentials and derive some useful formulae that show their complementary role in the description of thermodynamic systems with two degrees of freedom that show ensemble nonequivalence.

• From the expressions derived for the metrics, we can obtain the curvature scalars in a very simple and compact form.
• We explain here the reason why each curvature scalar diverges over the line of divergence of one of the specific heats.
• This application is of special interest in the study of changes of stability in black holes as defined by Davies.