Q&A with math professor Sergi Elizalde

by Arielle Beak | 10/15/18 2:25am

Sergi Elizalde is a math professor whose research focuses on enumerative and algebraic combinatorics. He came to the College in 2005 as a postdoctoral fellow and was hired as a professor in 2007. Elizalde is currently the East Wheelock house professor. He lives on campus with his wife and two children.

Can you briefly discuss your background and how you became interested in your field?

SE: I grew up in Spain, and when I was taking math classes there, I always liked math and I thought it was easier than other subjects. When I was in high school, there was this competition called the Math Olympiad, and I went to that and I did well, so then I went to the International Olympiad. I realized that it was something where I was better than some other people, so then I decided to apply to college in math. So the way it works in Spain, and I guess most European countries, you choose your major before you start. Math was actually even better in college because you learn why things are true, to prove things and to deduce other things. I also like how it’s sometimes like solving puzzles. It’s something I like doing, and even if I wasn’t paid for it, the fact that some of these “puzzles” are problems that people are interested in and have applications to other areas, I find fascinating. I can be doing something that I enjoy doing and also solving questions that other people care about.

What are you currently researching at Dartmouth?

SE: My field is called combinatorics. Combinatorics is about studying discrete structures you can count, so usually there’s a finite number of ways to do something and you count the number of ways it can be done. Some of my research is about DNA sequence alignment — there’s a lot of math in combinatorics behind DNA sequence alignment. I was able to use some math tools from probability to create what’s called a “Markov chain” that describes the evolution of a random cell in the model. We have written two papers already and we are working on another one. Some of my research is more in pure math, like combinatorics problems that aren’t directly related to biology necessarily, but this particular project right now is coming from biology. It’s something that cancer biologists really care about.

How has your experience been as the house professor of East Wheelock House?

SE: This is my fifth year [as a house professor]. Even before the house communities started, I already lived in this house, and the position was called faculty director of the East Wheelock cluster. East Wheelock already functioned very much like a house community with a difference that you had to apply — now it’s randomized. My position transitioned into house professor, and it’s been great. It’s been a lot of fun to interact with students, organize events and host dinners with faculty and artists. Now that the house communities have been going on for a couple of years, the students are getting more involved. Actually most of the events we do now come from students, and I just supervise them a little bit.

How has your experience been living in such close proximity to the school and raising your young children on campus?

SE: I have two kids, who are 9 and 3. My older one is at a public school in Hanover and my younger one is at Dartmouth daycare. They love having students around and will ask me when the next event will be. They know some of the students well so when they see them outside, they go out and play with them. It’s convenient for me to just walk to the math department, as it is very close by. I get to see students all the time through the window or when I go to the front porch.

What is your favorite part of your work here at Dartmouth?

SE: I feel the College has a lot of resources. For example, with the Formal Power Series & Algebraic Combinatorics conference I was asked to organize, the College helped a lot. I was able to apply for money from the College, which made the event run very smoothly. The school is very supportive. I feel the students are also very talented and motivated and it’s a great place to teach. I like the location too, and it’s such a nice place to raise kids.

What is a common misconception people have about the field of mathematics?

SE: Sometimes people think it’s either not very useful or they think it’s just computing the tip at a restaurant. When I’m with friends who are not in math and we have to compute the tip, they will be like, “Oh Sergi, you should be good at this,” but I don’t think I’m any better at computing a tip than people who don’t do math. It’s really not what we do — it’s not like we’re computing things in our heads and doing calculations. It’s more like abstract thinking and coming up with new ways to do something, so it’s very creative and not just applying a formula. That’s partly also why I like math research — you have to come up with new ideas all the time to solve problems no one has solved before. It’s the opposite of being repetitive.