**Maurício Peixoto** was a Brazilian mathematician who did outstanding work on the structural stability of dynamical systems. In a series of four papers he developed what today is known as Peixoto's Theorem.

- José Carlos de Matos Peixoto was professor of Roman Law at the Federal University of Rio de Janeiro and from 1928 to 1930 was governor of the State of Ceará.
- In 1930 an armed Revolution led to the President being deposed and José Carlos de Matos Peixoto was deposed as the governor of the State of Ceará.
- The Universidade do Distrito Federal was forced to close in 1939 when Peixoto had only completed one year of his studies.
- In 1939 Peixoto enrolled at the National School of Engineering at the University of Brazil in Rio de Janeiro.
- In 1943 Peixoto graduated with an engineering degree but he never intended to have a career as an engineer.
- Peixoto also attended lectures at the National Faculty of Philosophy at the University of Brazil by Luigi Sobrero and Gabriele Mammana.
- Peixoto also gave private mathematics lessons throughout his time as an undergraduate.
- After graduating, Peixoto was an assistant to the professor of Rational Mechanics at the National School of Engineering.
- Peixoto published the paper On the existence of derivative of generalized convex functions in that journal in 1948.
- Marshall Harvey Stone and Adrian Albert, both from Chicago, came to Rio de Janeiro on a State Department programme and Peixoto, together with his friend Leopoldo Nachbin, decided to try to obtain a Buenos Aires Convention scholarship to study at Chicago.
- On 21 September 1949, Peixoto was elected to the Brazilian Academy of Sciences.
- Peixoto gave the presentation Note on uniform continuity in the Analysis Section on the morning of Wednesday 6 September.
- Also in 1952 the Institute of Pure and Applied Mathematics (IMPA) was founded by Peixoto and his colleagues Leopoldo Nachbin and Lélio Gama.
- Peixoto began developing DeBaggis's ideas and wrote to Lefschetz in 1956 explaining the project he had set himself.
- Lefschetz was immediately interested and wrote back to Peixoto suggesting he apply for a Research Associate visiting position at Princeton.
- Peixoto delivered the short communication On structural stability.
- Articles that Peixoto published in 1959, 1962 and 1963 contain Peixoto's Theorem.
- the theorem of Peixoto on the structural stability in two-dimensional varieties inspired the mathematician S Smale to create the general theory of dynamic systems.
- Later, in evocative notes, Smale wrote about our meeting at Princeton and describes his reaction upon learning of the results that were supposed to appear in my Annals article: "Through Lefschetz, Peixoto became interested in structural stability and showed me his own results on structural stability in the disk (in an article due to appear in the "Annals of Mathematics, 1959").
- Let us return to Peixoto's career.
- In 1973 Peixoto was appointed as a professor at the Institute of Mathematics and Statistics at the University of São Paulo.
- In 2010 Peixoto was 89 years old.
- In that year Marcelo Viana, the director of the Institute of Pure and Applied Mathematics, wanted to select Peixoto's most important articles and publish them in a book.
- Peixoto suggested that Viana wait for a few years since he felt the work he was doing at the time should be included.
- Peixoto published four papers in 2011 and his final paper was published in 2014.

Born 15 April 1921, Fortaleza, Ceará, Brazil. Died 28 April 2019, Rio de Janeiro, Brazil.

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Origin Brazil

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