bibkey: dyson1949radiation authors: Freeman J. Dyson year: 1949 title: The Radiation Theories of Tomonaga, Schwinger, and Feynman doi: 10.1103/PhysRev.75.486 claim: Dyson’s time-ordered perturbative series is a classical origin of the ordered-exponential construction used in quantum dynamics. strata_touched:

• D5/S3/Quantum/Transport/MatrixUnitDyson license: citation-only triage: anchor

Historical origin of the Dyson terminology

Physical Review 75 (1949), 486-502. DOI: https://doi.org/10.1103/PhysRev.75.486

The time-ordered series is a classical construction. The finite-dimensional convergence and ODE facts used in the repository’s discussion are supported by Baake and Schlaegel, The Peano-Baker series, Section 2 and Section 3, https://arxiv.org/html/1011.1775v3. Their equation (4) and following discussion explicitly connect the Peano-Baker and Dyson terminology.

This historical citation is not a claim that Dyson’s paper proves the exact finite-interval Lean telescope, the independent Bochner simplex identity, the empty physical-index boundary, or the computed full matrix-unit transport formula. No Lean proof dependency or mathematical priority is inferred from this citation.

Verified locator

Verified DOI: https://doi.org/10.1103/PhysRev.75.486

Crossref’s DOI record identifies the title, F. J. Dyson, and publication on 1 February 1949. The Peano-Baker author version explicitly links the two series names. The historical primary paper has not been used as a substitute for the concrete finite-dimensional convergence argument.