**Iacopo Barsotti** was an Italian mathematician who worked in algebraic geometry.

- Barsotti was able to continue studying there and was awarded his laurea in 1942.
- Barsotti was not, therefore, in a position to publish material from his thesis until after the war ended.
- After Barsotti returned to Pisa, he helped with the restoration of teaching at the university.
- In those years the methods of modern algebra in algebraic geometry were almost unknown in Italy: in Rome it was only Barsotti who had already securely mastered them.
- Continued accusations against Severi made Barsotti's years as his assistant from 1946 to 1948 difficult ones.
- Notice that although Barsotti was Severi's assistant in Rome during 1946-48, he still gave his address as Pisa on the paper A proof of two fundamental theorems on linear transformations in Hilbert space, without use of the axiom of choice which he submitted to the Bulletin of the American Mathematical Society in March 1947.
- Barsotti's experience in Rome, with the continuing after-effects of the war, convinced him that he needed to leave Italy if he wanted to work in the most advanced schools of mathematics.
- The future papers that Barsotti referred to in this introduction appeared over the next years.
- In 1960 Barsotti moved to Brown University in Providence, Rhode Island but, while there, entered the competition for the chair of geometry and algebra at the University of Pisa.
- In addition to Barsotti, he appointed Aldo Andreotti and Edoardo Vesentini.
- While at Pisa, Barsotti published a series of seven papers entitled Metodi analitici per varietà abeliane in caratteristica positiva.
- His work in this area is remembered since his name has been attached to the Barsotti-Tate groups.
- Barsotti introduced these groups in his 1962 paper Analytical methods for abelian varieties in positive characteristic and named them equidimensional hyperdomain.
- John Tate worked on them five years later, calling them ppp-divisible groups, but the name Barsotti-Tate group is due to Alexander Grothendieck in 1971 who observed that these groups are naturally associated with the crystalline cohomology of a smooth scheme defined over a field of positive characteristic.
- Barsotti was not, however, to spend the rest of his career at Pisa for, in 1968, he moved to Padua to take up the chair of geometry at the university there.

Born 28 April 1921, Turin, Italy. Died 27 October 1987, Padua, Italy.

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Origin Italy

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive