Composite Systems, Holonomy, and Decoherence

This paper analyzes composite quantum systems from the perspective of bundle connections and holonomy. A geometric framework for composing subsystems is developed, and the behavior of phase information under restriction to subsystems is examined. It is shown that when access is limited to a subsystem, interference terms associated with relative phase can be suppressed in the reduced description, leading to additive weights for distinguishable components. This provides a geometric account of decoherence and the emergence of effectively classical behavior in composite systems. The analysis is formulated in terms of connection geometry and holonomy structure.