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Named after the German mathematicians Alfred Clebsch and Paul Gordan, who encountered an equivalent problem in invariant theory.
Etymology from Wiktionary, CC BY-SA 4.0.
Clebsch-Gordan coefficient
Today it means: Any of a class of numbers that arise in angular momentum coupling in quantum mechanics. They appear as the expansion coefficients of total angular momentum eigenstates in an uncoupled tensor product basis. Full definition →