Maite Arcos, Philippe Faist, Takahiro Sagawa, Jonathan Oppenheim (Oct 10 2025).
Abstract: In thermodynamics, an agent's ability to extract work is fundamentally constrained by their environment. Traditional frameworks struggle to capture how strategic decision-making under uncertainty -- particularly an agent's tolerance for risk -- determines the trade-off between extractable work and probability of success in finite-scale experiments. Here, we develop a framework for non-equilibrium thermodynamics based on adversarial resource theories, in which work extraction is modelled as an adversarial game for an agent extracting work. Within this perspective, we recast the Szilard engine as a game isomorphic to Kelly gambling, an information-theoretic model of optimal betting under uncertainty -- but with a thermodynamic utility function. Extending the framework to finite-size regimes, we apply a risk-reward trade-off to find an interpretation of the Renyi-divergences, in terms of extractable work for a given failure probability. By incorporating risk sensitivity via utility functions, we show that the guaranteed amount of work a rational agent would accept instead of undertaking a risky protocol is given by a Rényi divergence. This provides a unified picture of thermodynamics and gambling, and highlights how generalized free energies emerge from an adversarial setup.
