Thermodynamic geometry of charged rotating black holes in Einsteinian cubic gravity.

We study the thermodynamic geometry of two types of asymptotically anti-de Sitter black holes in four-dimensional Einsteinian cubic gravity, including the uncharged rotating and charged non-rotating black holes, applying the Ruppeiner thermodynamic geometry method. The divergence of the scalar curvature of the Ruppeiner metric ( R R ) is found to be related to the vanishing of the heat capacity. The stability of the solutions is shown to be affected by the Einsteinian cubic gravity coupling constant λ. In the unstable phase of the rotating black hole, the R R appeared to possess additional diverging points, where the number of these points and the behavior of R R are controlled by the angular momentum parameter. Also, for the charged non-rotating black hole case, we show that depending on the values of λ , the solution may enjoy two types of phase transition and R R behaviors. The characteristic behavior of R R of these two types of black holes enabled us to recognize the types of interactions between microscopic degrees of freedom. [ABSTRACT FROM AUTHOR]