01/08/2025

Jelani Nelson gives a lecture on computing and sketching at CBM.

On the afternoon of this Friday (1st), computer scientist Jelani Nelson, from the University of California at Berkeley, presented the plenary session "Sketching Algorithms", highlighting data structures that allow processing information with very little memory. The technique, essential for dealing with large volumes of data, was explained in a didactic and humorous way.

“I didn’t expect there to be so many people. They are people from all stages of their careers, from students to teachers. So, everything seems very lively to me. I don’t speak Portuguese, but I speak a little Spanish. Sometimes I try to understand things based on my Spanish, but it’s not perfect,” said Nelson.

The final plenary session of the 35th CBM highlighted the advantages of using a "sketch" in computing. Jelani explained that these structures require less space than the minimum theoretically needed to store all the information found in a database.

In addition to lower memory consumption, these resources are important for developing faster algorithms and reducing bandwidth demands in distributed computing environments.

IMPA doctoral student Daniel Perazzo, who collaborates with Visgraf (IMPA's Vision and Computer Graphics Laboratory), highlighted the speaker's teaching skills. “He presented very abstract topics, but with very simple examples. He showed the proofs in a way that everyone could understand. It was incredibly didactic. I especially liked the example of counting word frequency and its applications in graphs.”

Perazzo also celebrated the experience of participating in the Colloquium for the first time, which came with the presentation “An introduction to gaussian splatting”, in the Thematic Session on Vision and Computer Graphics, held last Monday (28). “I met people from all over Brazil, it’s a very rich space for exchange. I really enjoyed the experience,” he said.

The event had 1,500 registered participants.

This year, the 35th Brazilian Mathematics Colloquium broke a new record for registrations. This edition, held between July 28th and August 1st, had 1,500 participants who took turns attending plenary sessions, thematic sessions, mini-courses, poster sessions, and roundtables. In total, more than 200 presentations were made throughout the five days of the event.

The 35th edition was held in memory of the scientist Jacob Palis , who passed away in May at the age of 85. President of the Brazilian Academy of Sciences (ABC) for three terms and director-general of IMPA for ten years, Palis was one of the main figures in the development of mathematics in Brazil. Throughout his career, he trained generations of researchers and was a key figure in consolidating IMPA as a world-class center of excellence.