George Ruppeiner

Thermodynamic curvature and phase transitions in Kerr-Newman black holes

Singularities in the thermodynamics of Kerr-Newman black holes are commonly associated with phase transitions. However, such interpretations are complicated by a lack of stability and, more significantly, by a lack of conclusive insight from microscopic models. Here, I focus on the later problem. I use the thermodynamic Riemannian curvature scalar

Simulated annealing with constant thermodynamic speed

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Thermodynamic geometry, phase transitions, and the Widom line.

as a try to get microscopic information from the known thermodynamics. The hope is that this could facilitate matching black hole thermodynamics to known models of statistical mechanics. For the Kerr-Newman black hole, the sign of

Thermodynamic Curvature and Black Holes

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Thermodynamic curvature from the critical point to the triple point.

is mostly positive, in contrast to that for ordinary thermodynamic models, where

Ultrasonic propagation in3He-4He mixtures near the tricritical point

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Thermodynamic curvature: pure fluids to black holes

is mostly negative. Cases with negative

Transport phenomena in He3-He4 mixtures near the tricritical point

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Measuring the electrical conductivity of the earth

include most of the simple critical point models. An exception is the Fermi gas, which has positive

Implementation of an adaptive, constant thermodynamic speed simulated annealing schedule

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