Born: 20 Jan 1904 in Naples, Italy
Died: 8 May 1959 in Naples, Italy
Renato Caccioppoli was one of the most interesting and charming mathematical figures of the 20th century. He began his studies in engineering, but eventually focused on mathematics, and earned his degree from the University of Naples in 1925. His publications delt with integration on k-dimensional varieties, to establish " the principles of a theory of measure of plane and curved surfaces, and more generally of two or more dimensional varieties embedded in a linear space", and also differential equations.
In my humble opinion, however, he was more interesting outside of mathematics.
In May 1938 Hitler was visiting Naples with Mussolini. Caccioppoli, who had already shown his opposition to fascism, convinced an open-air restaurant orchestra to
play La Marseillaise, and made a speech against Italian and German dictators. (Remind anyone of Casablanca?)
He was arrested and he should have been tried by a special political court instituted by the fascists against their opponents , but he managed - with the help of his
aunt Maria Bakunin who was a chemistry teacher at the University of Naples - to be declared mad and to be eventually sent to an asylum.
To avoid any contact with official academic institutions, which were strictly controlled by the fascist dictatorship, he published (1940) his results in "Commentationes
Pontificiae Academiae Scientiarum", a scientific review published in the Vatican State. His political opposition to fascism led him to organise a strike in Naples in
1943.
After the Second World War Renato Caccioppoli resumed his scientific activity. He was elected a corresponding Fellow of the Accademia Nazionale dei Lincei,
later becoming a National Fellow (1958). He was also member of various Academic Institutions. During these years he joined the Italian Communist Party, although
he did not entirely share the party's policy nor did he agree with the official Soviet vision of science. He joined the "peace partisans", a left-wing organisation
supporting disarmament. He also founded a cultural association, the "Circolo del cinema", a film club.
In 1952 Caccioppoli sketched a revised vrsion of his early work on surface area and related topics, with the article "Misura e integrazione degli insiemi
dimensionalmente orientati", (Rend. Acc. Naz. Lincei, s. VIII, v.12). In this work he focused his attention on the theory of "dimensionally oriented sets", namely
surfaces of "nice" subsets of Euclidean space. These finite perimeter sets which were introduced by Caccioppoli are now known as "Caccioppoli sets".
The last years of his life were sad ones: Caccioppoli saw his political hopes disappointed, probably felt that his mathematical inspiration had run out, and his wife,
Sara Mancuso, eventually left him. He took to drink and he became more and more isolated. He shot himself on 8 May 1959.
In 1992, a film Morte di un matematica napoletono ("Death of a Naples mathematician") was made by the Italian director Mario Martone about the events
leading to Caccioppoli's suicide.
The Mathematics Department at the University of Naples is named after Renato Caccioppoli.
from The University of St. Andrews
at http://www-groups.dcs.st-andrews.ac.uk/~history/Mathematicians/Caccioppoli.html