Heat as a gauge connection
Bryan W Roberts
TL;DR
This work reframes thermodynamics as a gauge-theoretic problem by modeling a thermodynamic system as a line bundle over work configurations, with heat given by the nowhere-vanishing 1-form $\boldsymbol{\xi} = dU + \boldsymbol{\omega}$. The central result shows that heat defines a connection on this bundle, and that a locally integrating factor (an entropy–temperature pair with $\boldsymbol{\xi} = T dS$) exists if and only if the connection has vanishing curvature, i.e., is integrable. The authors derive a gauge-theoretic proof of Jauch's conjecture as a special case and identify a thermal analogue of geometric phase responsible for the possible failure of global equilibrium, linking holonomy to global nonequilibrium. Overall, the paper advances a perspective in which thermodynamics arises as a special case of gauge theory, with local thermodynamic quantities tied to curvature and global behavior governed by holonomy and geometric phase.
Abstract
We show that heat defines a gauge connection on a line bundle over work configurations. Vanishing curvature is equivalent to the local existence of entropy and temperature functions such that heat can be expressed as $TdS$. A conjecture of Jauch, that entropy and temperature arise from a conservation law, is shown to follow as a special case. Global equilibrium may nevertheless fail in the presence of a thermal analogue of geometric phase.
