[The University of Texas at Austin: What starts here changes the world]
Theory Group
Theory Group Special Seminar, 18 April 2018


Ted Jacobson, University of Maryland

Gravitational Thermodynamics of Causal Diamonds

abstract

Black hole (more generally, horizon) thermodynamics is a window into quantum gravity. Can horizon thermodynamics---and ultimately quantum gravity---be quasi-localized? A special case is the static patch of de Sitter spacetime, known since the work of Gibbons and Hawking to admit a thermodynamic equilibrium interpretation. It turns out this interpretation makes sense only if a negative temperature is assigned to the state. I'll discuss this example, and its generalization to all causal diamonds in maximally symmetric spacetimes. This story includes a Smarr formula and first law of causal diamonds, analogous to those of black hole mechanics. Hopefully I can also explain the evidence that the entanglement entropy in a small diamond is maximized in the vacuum at fixed volume.



This page was last updated on 19 April 2018
Texas Cosmology Center   ♦   Physics Department   ♦   University of Texas at Austin