Stories about the admirable Professor Elon Lages Lima

If the teacher taught something wrong, the boy from Alagoas, with his fair complexion and very blue eyes, didn't think twice and quickly corrected him. He interrupted so often that the young man ended up being called in for a talk. Already aware of the student's excellent performance, the then-director of the Cadet Preparatory School was direct: “The last student we had with such high grades was Luis Carlos Prestes. So, you are expelled!”, he said, referring to the communist leader.

The story brought laughter to the audience that filled the Ricardo Mañé auditorium at IMPA on Thursday afternoon, for a tribute to the protagonist of the story, the mathematician Elon Lages Lima, who died at age 87 in May of this year. For almost two hours, participants of the 31st Brazilian Mathematics Colloquium, work colleagues, former students, and family members of the researcher recalled or learned about moments from his career.

“He was central to Brazilian mathematics for several reasons. He was the main writer of mathematics textbooks in Brazil and helped to train several generations. For that reason alone, he was already a transcendental figure,” observed the mathematician Carlos Gustavo Moreira, known as Gugu, recalling that he met Elon in his adolescence, when he took a summer course at IMPA and became part of a Scientific Initiation group that he had created.

Gugu interspersed anecdotes with Elon's numerous achievements. One of the first scholarship recipients at IMPA, an institution he directed on three occasions (1969-71, 1979-80 and 1989-93) and where he worked until his death, he helped create university courses in Mathematics, played a fundamental role in the construction of the IMPA library, and created, in 1990, the Program for the Improvement of High School Mathematics Teachers (PAPMEM), which has already trained more than 20,000 teachers throughout Brazil. As a researcher, he dedicated himself to differential and algebraic topology and differential geometry.

PAPMEM coordinator Eduardo Wagner highlighted that Elon's concern with teacher qualification arose very early on. It was driven by this interest that the native of Alagoas created, in 1982, the Revista do Professor de Matemática (Mathematics Teacher's Magazine), a publication that continues uninterrupted to this day. Elon wrote a section called "Concepts and Controversies." But only those less attentive to the master's style didn't suspect that, in fact, he wrote much more, hidden behind two frequent collaborators, named Euclides Rosa and Zoroastro Azambuja Filho.

IMPA's outstanding researcher, Artur Avila, solved one of Elon's exercises for the audience. He recalled that, until his doctorate, he studied mathematics using Elon's books. He won his first titles after being awarded a prize in a Mathematics Olympiad. Later, he started buying others, eventually forming a foundational collection. The author eventually became his master's thesis advisor at IMPA. "For two years, I went to his office quite frequently," Artur recalled, emphasizing that Elon gave extremely clear lectures and was very rigorous. "But he had a lot of patience with me."

In room 322, yet another tribute.

A leading figure in the field of Number Theory, mathematician and former IMPA researcher Paulo Ribenboim also paid tribute. He noted that the reason for being there was sad, but an opportunity to express how important Elon was to mathematics. He highlighted the intelligence, honesty, morality, and patriotism of the man from Alagoas and told a story to illustrate the love he felt for the country. “Elon had a promising career in the best places in the United States, but his heart beat for Brazil. It beat, beat, beat, he came back and did everything he did. I have unparalleled admiration for him.”

In the photo session shown throughout the presentation, IMPA's emeritus researcher, Jacob Palis, was a constant presence. Regarding his friend, he recalled his generosity and recounted how he was instrumental in the course of his professional life. He mentioned having dared to ask Elon and Maurício Peixoto (one of the founders of IMPA) who the most important foreign mathematician who had been in the country in recent years was. Elon cited the American Stephen Smale, Fields Medal winner in 1966. “I wrote and said I wanted to work with him. And, to my surprise, he replied yes. I think they (Elon and Maurício) spoke well of me. And that changed my life,” Jacob said.

Shortly after, a plaque in honor of Elon was unveiled by his widow, Carolina Celano. It was affixed to the entrance of room 322, which the researcher occupied.