Uppsala mathematician receives Wallenberg Prize
plit trees are randomly constructed trees often used to represent sorting algorithms in computer science, where the individual ‘balls’ represent data to be sorted in order. Photo: Johan Marklund
Cecilia Holmgren, Professor of Probability Theory and Combinatorics at the Department of Mathematics, Uppsala University, has been awarded one of this year's Wallenberg Prizes for her work on random trees.
“I hope to inspire students, especially women, to study mathematics and also to attract more young researchers to my research group.”
The Wallenberg Prize in Mathematics is awarded by the Swedish Mathematical Society with the support of the Marcus and Amalia Wallenberg Memorial Foundation. It has been awarded annually since 1983 to particularly promising young Swedish mathematicians and is the most prestigious award that a young Swedish mathematician can receive in Sweden.
This year it is shared between Cecilia Holmgren at Uppsala University and Malin Palö Forsström at Chalmers. According to the award committee, Cecilia Holmgren receives the prize for her ‘important and versatile contributions to the theory of random trees.’
Congratulations on winning the Wallenberg Prize 2024, Cecilia! What does this prize mean to you?
“Thank you! It's very nice to receive confirmation that my research is also important to other than myself.”
What is your field of research, random trees, about?
“In simple terms, many real-world structures are best modelled using randomness, such as how an infection can spread in society, how servers on the internet are connected to each other, or how quickly a database can be searched. Random trees and graphs allow us to model such problems, and are also used in modern AI research.”
Models for many different research problems
Cecilia Holmgren is particularly known for her work on split trees, a collection of models that includes many important classes of random trees and can often be seen as graphical models of computer algorithms.
“What is special about my research is that it provides generalised results that can be applied to many different models simultaneously, which means that my results have the potential to contribute to many different research problems.”
One area that particularly interests her is percolation theory, where very small changes in a parameter have large consequences for the model. She likens it to physics, where water behaves very differently depending on whether the temperature is just above or just below zero. Or that a small difference in vaccination rates can determine whether a disease spreads in society or dies out.
What would you like to work on in the future?
“The research that led to the award has opened up a range of new questions that I hope to explore further in the future. There, AI has also emerged as a very hot area with clear links to my field. My research philosophy of finding generalised results for many different problems at the same time is something I want to continue with in the future,” says Cecilia Holmgren.
Anneli Björkman
The Wallenberg Prize
The Wallenberg Prize is accompanied by a prize money of SEK 300,000, which will be divided equally between the two winners. The prize will be awarded at the Swedish Mathematical Society's autumn meeting in Umeå on Friday 22 November.