Ian Nagle (Amsterdam Univ.)
General Relativity from Thermodynamics: A Different Perspective on the Wald Entropy
General relativity is a thermodynamic theory that is consistent with the holographic principle. However, the precise manner in which this description emerges from an underlying theory is unknown. Here I concentrate on the relation between fluids, gravity, and the membrane paradigm to further elucidate this link. In the membrane paradigm, black holes are viewed holographically, by excising their interior, truncating fields on the surface, and imbuing the horizon with surface properties such as viscosity, resistivity, and thermal dissipation. Connecting this approach with the thermal derivation of general relativity by T. Jacobson, a first law of thermodynamics is constructed which is equivalent to an initial value formulation of relativity, and offers a new perspective on the Wald Noether charge approach to the Bekenstein-Hawking entropy.