# Thermodynamics of spacetime: The Einstein equation of state.

@article{Jacobson1995ThermodynamicsOS,
title={Thermodynamics of spacetime: The Einstein equation of state.},
author={Jacobson},
journal={Physical review letters},
year={1995},
volume={75 7},
pages={
1260-1263
}
}
• Jacobson
• Published 4 April 1995
• Physics
• Physical review letters
The Einstein equation is derived from the form of black hole entropy together with the fundamental relation $\delta Q=TdS$ connecting heat, entropy, and temperature. The key idea is to demand that this relation hold for all the local Rindler horizons through each spacetime point. Viewed in this way, the Einstein equation is an equation of state. It is born in the thermodynamic limit as a relation between thermodynamic variables, and its validity is seen to depend on the existence of local…
1,663 Citations
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