Demystifying the fractional order phase transitions in AdS black holes

In this work, we performed a detailed study of the fractional order phase transition (FPT) for several AdS black hole prototypes [1]. Our objective is to see whether the FPT 4/3 order at critical points reported in [2] is universal. Our analysis shows two remarkable features: Firstly, the FPT is located at 4/3 order only when the black hole possesses a spherical symmetry. Secondly, this fractional order is not universal and can be altered by the geometric symmetry.