14/05/2025

Folha: 'Jacob Palis, master, leader, giant'

Reproduction of Marcelo Viana's column in Folha de São Paulo.

On March 15, 2019, UNESCO held the event "Development of Mathematics , Mathematics of Development" at its headquarters in Paris. Brazil was chosen as a case study, and I was invited to explain to the international audience how the country built, practically from scratch and in just a few decades, a mathematical community of high international standard, capable even of nurturing within its ranks a Fields Medal winner , such as Artur Avila .

Étienne Ghys, professor at the École Normale Supérieure de Lyon, perpetual secretary of the French Academy of Sciences, and a long-time Brazilian at heart, was the moderator. He gave a bit of a spoiler for my lecture: "Mathematics in Brazil was launched by a handful of giants who gave up promising careers in North America to return to a country without a tradition in scientific research and make a difference." What followed was, to a large extent, a tribute to the greatest of these giants, Jacob Palis , a researcher at the Institute of Pure and Applied Mathematics (IMPA).

I met Jacob in September 1985, at a mathematics conference at the University of Coimbra. He was the keynote speaker, who was going to give the closing lecture. I was a young recent graduate who arrived at the conference wanting to present a paper I had just completed, my first theorem.

Intimidated by the solemnity of the situation, I was relieved when my lecture was scheduled for 8:30 pm on Friday: only very dear friends would be present at that time! But the mutual colleagues who introduced us also told Jacob about the lecture, and he didn't hesitate: "I'll attend, Marcelo!"

His presence attracted many others: at the time, the room was completely packed, which did nothing to alleviate my nervousness. Disguising it as best I could, I delivered my presentation. At the end, Jacob invited me to do my doctorate at IMPA. Six months later I was here, and my life has never been the same.

During the years I spent as his doctoral advisee, I learned that being interested in what an unknown boy might have to say was typical of the person and the scientist he was. No subject relevant to scientific research failed to capture his attention. I was always amazed at how he always managed to fit more interests into his overloaded schedule, as if time were elastic. To this day I'm still trying to learn the technique, but I haven't quite gotten there yet.

A colleague who knew about birds once told me that in certain species there are individuals who are particularly valued, not only because they sing very well but, above all, because they encourage others to sing as well. Because of his charisma, generosity, and contagious enthusiasm, Jacob had this ability to inspire those around him. Throughout his academic life, he supervised 41 doctoral students and impacted the lives of many more scientists around the world.

According to Lan Wen, a professor at Peking University in China , "Jacob had a special personality that attracted everyone who knew him. He was a friend of the Chinese mathematical community, which he helped integrate into the international community. We, Chinese mathematicians, are grateful to him. His name and his smile will stay with us forever."

Meysam Nassiri, who was his doctoral student and is now a professor at the University of Tehran in Iran , sent me a beautiful inscription in Persian defining him as "a man imbued with greatness, whose extraordinary vision and character contributed in a transformative and lasting way to the growth of new generations and the advancement of science and mathematics in Brazil and throughout the world."

Slimane ben Miled, a researcher at the Pasteur Institute and professor at the University of Tunis in Tunisia, who did his postdoctoral work in Rio de Janeiro in the 1990s, states: "I want to testify to the importance that Jacob had not only in my scientific life, but beyond. His way of seeing problems marked me deeply."

According to Servet Martinez, professor at the University of Chile and former president of the Mathematical Union of Latin America and the Caribbean, "besides being an exceptional mathematician, he was a giant in scientific achievements in our Latin America, and a great friend of Chile."

Prominent mathematicians of his time also expressed their admiration. Dennis Sullivan, a professor at the City University of New York and one of the great topologists of our day, wrote to me that "Jacob inspired other people to learn dynamical systems. He made good things happen, with good feelings." David Mumford, a professor at Brown University and winner of the Fields Medal in 1974, stated that "Jacob was a wonderful person, with the ability to make things happen in the world of mathematics, and a fantastic friend."

And it wasn't just people: Jacob equally impacted the many institutions where he worked, always in a prominent way and in leadership positions. The Brazilian Academy of Sciences, which he presided over from 2007–2016, and the Academy of Sciences for the Developing World (TWAS), of which he was also president from 2007–2012. The International Mathematical Union, on whose executive committee he served for a record time (24 years!), culminating in his presidency from 1999–2002. And IMPA, of course, his home, which he directed from 1993–2003 and led for much longer.

To all these institutions he brought his remarkable strategic vision, which allowed him to discern the paths to follow, his recognized political astuteness, and extraordinary energy to guide the institution along those paths. I saw all of this in action when, around the year 2000, he led the conversion of IMPA into a social organization linked to the Ministry of Science and Technology. A radical change for a public institution with almost half a century of existence, which Jacob made seem easy. The institute's progress in the subsequent quarter-century is compelling proof of the wisdom of this decision.

Read the full article on the Folha de São Paulo website.