The continuous observable trace pairing
Abstract
Analytic trace norms and bounded trace pairings on arbitrary complete complex Hilbert spaces.
Theorem 1.1 (The continuous observable trace pairing).
Proof. Machine-checked in Lean as D5/S3/Quantum/Analysis/TraceClass/Pairing.tracePairingContinuousLinearMap_apply (✓ std3). ∎
Citation. Tom Ole Diem (2026). Analytic trace-class and Hilbert-Schmidt operators. URL: https://github.com/leanprover-community/physlib/tree/b9043cc548ef6d63a28454cf3a57fb12a0c2e142/PhyslibAlpha/AlgebraicFramework/HilbertSpace/TraceClass.
Commentary.
The map sending a bounded A to the functional T maps to Tr(A T) is complex linear and continuous from the operator norm into the strong dual of the genuine trace-class Banach space. Its norm is bounded by one. The trace-class slot uses the trace norm.
Attributed to Tom Ole Diem, Physlib at immutable revision b9043cc548ef6d63a28454cf3a57fb12a0c2e142, Apache-2.0. The original copyright notice and license are preserved. No mathematical originality is claimed for these suppliers.