Spacetime Equilibrium at Negative Temperature and the Attraction of Gravity

Abstract

We derive the Einstein equation from the condition that every small causal diamond is a variation of a flat empty diamond with the same free conformal energy, as would be expected for a near-equilibrium state. The attractiveness of gravity hinges on the negativity of the absolute temperature of these diamonds, a property we infer from the generalized entropy.

arXiv comment7 pages, Essay written for the Gravity Research Foundation 2019 Awards for Essays on Gravitation

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Cited by in corpus (11)

• Gravitational Thermodynamics of Causal Diamonds in (A)dS
• The minus sign in the first law of de Sitter horizons
• Thermodynamic ensembles with cosmological horizons
• Conformal Description of Near-Horizon Vacuum States
• Microcanonical Action and the Entropy of Hawking Radiation
• Strong-coupling dynamics and entanglement in de Sitter space
• Thermodynamics of spacetime and unimodular gravity
• The first law of differential entropy and holographic complexity
• From spacetime thermodynamics to Weyl transverse gravity
• Emergence of quadratic gravity from entanglement equilibrium
• Spacetime granularity from finite-dimensionality of local observable algebras