# Taub-Bolt Heat Engines

## TL;DR

This paper explores the thermodynamic properties of Taub-Bolt-AdS spacetime, establishing its similarity to Schwarzschild-AdS black holes, and introduces the concept of gravitational heat engines based on Taub-Bolt spacetime, analyzing their efficiency.

## Contribution

It is the first to define holographic heat engines using Taub-Bolt spacetime, extending gravitational thermodynamics beyond black holes and comparing engine efficiencies.

## Key findings

- Taub-Bolt thermodynamics closely resemble Schwarzschild-AdS at high temperatures.
- Holographic heat engines can be constructed from Taub-Bolt spacetime.
- Engine efficiencies are comparable between Taub-Bolt and Schwarzschild black hole cycles.

## Abstract

It is shown that aspects of the extended thermodynamic properties of the Taub-Bolt-AdS spacetime in four dimensions are similar to those of the Schwarzschild-AdS black hole. In a high temperature expansion, the equations of state begin to deviate only at next-to-subleading orders. By analogy with what has been done for black holes, Taub-Bolt's thermodynamic equations are used to define holographic heat engines, the first examples of gravitational heat engines defined using a spacetime that is not a black hole. As a further comparison, the Taub-Bolt engine efficiency is computed for two special kinds of engine cycle and compared to the results for analogous Schwarzschild black hole engine cycles.