Giulio (Yoel) Racah (Hebrew: פרופסור (יואל) רקח‎; 1909 - August 28, 1965) was an Italian-Israeli physicist and mathematician.

Born in Florence, Italy, he took his PhD from the University there in 1930, and later studied in Rome with Enrico Fermi. In 1937 he was appointed Professor of Physics at the University of Pisa. In 1939, due to appliction of Anti-Jewish laws in Italy, Racah immigrated to the British Mandate of Palestine, and was appointed Professor of Theoretical Physics at the Hebrew University of Jerusalem, where he was later Dean of the Faculty of Sciences, and finally Rector and acting President.

Racah's research was mainly in the fields of quantum physics and atomic spectroscopy. He first devised a systematic general procedure for classifying the energy levels of open shell atoms, which remains to this day the accepted technique for practical calculations of atomic structure. This formalism was described in a monograph coauthored by his cousin: Ugo Fano (Irreducible Tensorial Sets, 1959). In 1958 he was awarded the Israel Prize for lifetime contribution to physics.

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