Schwarzschild-plus-reservoir model

Inspired by the success of system-plus-reservoir models in the theory of open systems, we investigate the dynamics of spacetime as an open system. As a preliminary step toward a comprehensive gravitation-plus-reservoir framework, we present a Schwarzschild-plus-reservoir toy model, where the influence of unknown or inaccessible degrees of freedom is captured through an interacting reservoir. The potential of this approach is illustrated by modeling quasistatic accretion processes.