Black hole thermodynamics, a subject more than 40 years old, is undergoing a renaissance. By taking proper account of vacuum energy, physicists have come to realize that the cosmological constant behaves as thermodynamic pressure. This realization has proven to be very fruitful, and whole variety of new thermodynamic phenomena have been discovered that indicate black holes can behave very much like chemical phenomena from everyday life.
In this series of lectures I will describe this newly emerging subject of “Black Hole Chemistry”. The mass of a black hole is no longer regarded as internal energy, but rather as chemical enthalpy. A notion of thermodynamic volume emerges for all black holes, and is connected with an inequality imposing a bound on the amount of entropy black hole can carry for fixed thermodynamic volume.
New thermodynamic phase transitions can take place, including as Van der Waals liquid/gas transitions, reentrant phase transitions, triple points, polymer-like transitions, and even transitions resembling those of superfluid helium.
I will close by reviewing recent attempts at extending the AdS/CFT dictionary in this setting, and discuss connections with horizon thermodynamics, Lifshitz spacetimes, and outline possible future directions in this field.
Based on 1608.06147 (and many other references)