Eugenio Calabi

Eugenio Calabi (1923-2023) was an Italian-born American mathematician and the Thomas A. Scott Professor of Mathematics at the University of Pennsylvania, specialising in differential geometry and partial differential equations. Born in Milan into a Jewish family, he left Italy with his family in 1938 because of the racial laws and reached the United States in 1939. He studied at the Massachusetts Institute of Technology, finished his bachelor's degree after wartime service, took a master's degree at Illinois in 1947 and a doctorate at Princeton in 1950 under Salomon Bochner. He taught at Louisiana State University and Minnesota before joining Pennsylvania in 1964, was elected to the National Academy of Sciences in 1982 and received the Steele Prize in 1991. His best known work is the Calabi conjecture on prescribing the Ricci curvature of a Kähler metric, proved by Shing-Tung Yau in the 1970s, which gave the Calabi-Yau metrics that matter in string theory. He also introduced the Calabi flow and extremal Kähler metrics and found the Laplacian comparison theorem. He died in 2023 at the age of one hundred.