When Louigi Addario-Berry found out he was being named a Fellow of the Institute of Mathematical Statistics (IMS), Fellow, he was understandably honoured. With 3,500 active members, the IMS is the premier organization of mathematical statisticians and probabilists in the world.

But what really struck him was the IMS citation that said he had earned the Fellowship “for fundamental contributions to probability, in particular to the topics of branching structures and random graphs, and for his devoted service to the mathematical sciences and promotion of diversity within them.”

“I am really touched by the second half of the citation,” Addario-Berry told the Reporter via email. “The longer my career goes on, the more acutely I feel how lack of diversity impoverishes our community. The road to a successful research career isn’t easy for anyone, but that doesn’t make it a level playing field. I’ve been doing my best for a long time to try to make my corner of mathematics a more welcoming place, and it’s really nice to have that recognized in such an official sort of way.”

**Complex issues of equity, diversity and inclusion**

But issues of equity, diversity and inclusion (EDI) are layered and Addario-Berry acknowledges this complexity.

“At the same time as being moved by the citation, I am a little uncomfortable about it,” says the Associate Professor in the Department of Mathematics and Statistics. “I think the main source of this discomfort is a suspicion that if I were from a minority group within my field, receiving IMS fellowship with this same citation, the mention of diversity would be seen as diminishing or casting a shadow on my other, ‘scholarly’ achievements. So, I guess I feel somewhat guilty about the fact that being recognized for this sort of contribution is less fraught for me than it would be for many others.

“That said, I am very glad that my professional society, the IMS, views devoted service to the promotion of diversity within the mathematical sciences as worthy of recognition,” says Addario-Berry. “And I am glad to know that I am just one of many, many friends and allies in the struggle to make our community a welcoming place for all.”

**Math or philosophy?**

When Addario-Berry began teaching at McGill in 2009, it was a homecoming. “I did all my degrees at McGill,” he says. “I started my undergrad in 1997 and finished my PhD in 2006. I then did a postdoc in the UK for two years and spent one year as an assistant professor at Université de Montréal, before returning to McGill as an associate professor.”

It was at McGill that Addario-Berry found his passion for statistics – even though he came very close to switching careers.

“My interests were all over the place during my studies. I even considered switching from math to philosophy partway through my doctoral studies,” he says. “My interest in probability and statistics essentially dates to when I took courses from some particularly inspirational McGill professors: David Wolfson https://www.mcgill.ca/mathstat/david-b-wolfson and Vojkan Jaksic http://www.math.mcgill.ca/jaksic/ in the Math Department, and Luc Devroye http://luc.devroye.org/ in the Computer Science Department. I got a much better understanding of the landscape of current research in the area (and its massive breadth) during my postdoc, in particular through the research projects I started with Christina Goldschmidt [at the University of Oxford], some of which are still ongoing 15 years later!”

**Buoyed by momentum of social progress movement**

Like so many people, Addario-Berry has been adjusting to the new reality imposed upon the world by COVID-19, calling the juggling of professional and family commitments “pretty intense.”

Not surprisingly, given his commitment to EDI issues, Addario-Berry is keenly interested in the growing movement for social reform, here in Canada and around the world. “At the moment the protests against racist police violence feel more urgently important even than the pandemic,” he says. “The honor conferred on me by the IMS was a lovely bit of news, but the massive upwelling of support for a more just society, and the social progress that is resulting from the protests and from the related collective actions, has been the biggest boost to my mental health in the last while.”

**EDITOR’S NOTE:** After we posted this article, Sherry Olson, Professor Emerita in the Department of Geography, sent a note asking if we could include an explanation of Addario-Berry’s research. We asked Addario-Berry if he could synopsize his work in layperson terms. This is what he said:

“My research is mostly focussed on the analysis of idealized mathematical models of physical systems, with the aim of explaining some of the fundamental properties we observe in the world around us.

One good example is how water has a melting point; and so does iron, and gold, and nitrogen, and any other element you can name, as well as many molecules. The melting points may be different, but the basic phenomenon is quite universal. Why is this? Why aren’t there elements which gradually get softer over a range of temperatures, rather than having a fixed temperature where the substance changes abruptly from solid to liquid?

So this behaviour – a phase transition from solid to liquid – seems to be quite “robust,” not depending too much on the precise structure of the underlying atoms or molecules. It would be fantastic to have an explanation of why this behaviour occurs which is similarly robust. This means looking for an explanation which doesn’t depend too much on the precise microscopic characteristics of the underlying physical system. This is where math comes in; we would like to find mathematical models which are simple enough to rigorously analyze, and which accurately capture the phenomenology of phase transitions in physical systems.

Probability and statistics come in because at the atomic level, physical interactions are random. A big part of modern probability theory is devoted to explaining how at a large scale, systems can be predictable and, indeed, can even appear fully deterministic, when those systems are fundamentally determined by large numbers of random interactions.”

Today none of your links seems to work.

Among other things, I wanted to look up Addario-Berry’s work – you featured his ‘diversity’, but you didn’t say a thing about hiscontributions to math and probability.

Are the rest of us not supposed to understand probability?

Excellent point, Professor Olson. We have updated the article!