We were deeply saddened to learn of the death of Eugenio Calabi, an Italian-born American mathematician and Professor Emeritus at the University of Pennsylvania, at the age of 100 years and 4 months. A specialist in differential geometry and partial differential equations, he was notably recognized for his outstanding coverage of geometry in many facets, with numerous and varied contributions.
His conjecture concerning a fundamental question of Kählerian geometry structured research in this field for many years, leading to the systematic exploration of Calabi-Yau varieties by numerous mathematicians and theoretical physicists.
In 1991, he was awarded the Leroy P. Steele Prize “for his fundamental work on global differential geometry, and more particularly on complex differential geometry”. In 2012, he was elected Fellow of the American Mathematical Society and in 2022 named Commander of the Order of Merit of the Italian Republic.
After a first visit in 1968, Eugenio Calabi became a regular visitor to the Institute, with which he has always maintained close ties. In 2007, he returned to IHES for the last time, for a conference in honor of the 60th birthday of Jean-Pierre Bourguignon, then Director. In addition to his close ties with IHES scientists, Eugenio and his wife Giuliana had been donors of the Institute for many years,
His Collected Works were published by Springer in 2022, with Jean-Pierre Bourguignon, Chen Xiuxiong and Simon Donaldson as editors. A tribute to his 100th birthday was published by the European Mathematical Society in its June 2023 Magazine.