2025/02/05 by Nikesh Lilani, Lilani, Nikesh, Manus R. Visser +1 · 1 voice
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Quantum chaos and dynamical systems #Relativity and Gravitational Theory #Statistical Mechanics (cond-mat.stat-mech) #cond-mat.stat-mech #gr-qc #hep-th
paper · pdf · doi:10.48550/arxiv.2502.03363
openalex publication_date 2025/02/05 · arxiv published 2025/02/05 · arxiv updated 2025/09/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
According to holography, a black hole is dual to a thermal state in a strongly coupled quantum system. One of the best-known examples of holography is the Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence. Despite extensive work on holographic thermodynamics, heat engines for CFT thermal states have not been explored. We construct reversible heat engines where the working substance consists of a static thermal equilibrium state of a CFT. For thermal states dual to an asymptotically AdS black hole, this yields a realization of Johnson's holographic heat engines. We compute the efficiency for a number of idealized heat engines, such as the Carnot, Brayton, Otto, Diesel, and Stirling cycles. The efficiency of most heat engines can be derived from the CFT equation of state, which follows from scale invariance, and we compare them to the efficiencies for an ideal gas. However, the Stirling efficiency for a generic CFT is uniquely determined in terms of its characteristic temperature and volume only in the high-temperature or large-volume regime. We derive an exact expression for the Stirling efficiency for CFT states dual to AdS-Schwarzschild black holes and compare the subleading corrections in the high-temperature regime with those in a generic CFT.