# Spacetime Equilibrium at Negative Temperature and the Attraction of Gravity

## TL;DR

This paper derives Einstein's equation from thermodynamic principles, showing that gravity's attractive nature is linked to the negative temperature of causal diamonds, based on generalized entropy considerations.

## Contribution

It introduces a thermodynamic derivation of Einstein's equation emphasizing the role of negative temperature in gravity's attraction.

## Key findings

- Gravity is derived from thermodynamic conditions of causal diamonds.
- Negative temperature of these diamonds explains gravity's attractive nature.
- Generalized entropy underpins the thermodynamic approach.

## 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.