Full-State and Reduced-Moment Encodings: A Representation-Level View of Equilibrium Quantum Many-Body Theory
This paper proposes a unified representation-level framework for equilibrium quantum many-body theory that characterizes different methods as encoders mapping admissible states to specific variables, thereby clarifying the conditions for exact reconstruction and unifying concepts like functionals, kernels, and quantum embedding through the analysis of state fibers and task-relevant information.