Santiago Segarra - About me

Postdoctoral Research Associate (

I was born in Buenos Aires, Argentina, in 1988. I have three older brothers. My parents and two of my brothers are currently living in Buenos Aires and the other one lives in Brazil. I also have a wife called Belén. We have been together for more than ten years now but we just got married this past December.

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Having grown up in Argentina, football (soccer for my US friends) is a big part of my life. I enjoy watching it but mainly I like to play it. In 2005, with some high school friends, we started a football team and played several amateur tournaments in Argentina. We have played together every week since then. The team is called “Roberto Gomez Bolaños” (RGB) to honor this man, a childhood hero in Latin America. Although I cannot play very frequently in the team now due to geographical restrictions, I always follow their results closely. You can do it as well, in this tournament page.

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I enjoy reading and writing. I have read books from different topics and genres. In the past few years, I read books that go from the scholarly rigor of Descartes and Pólya to the fantastic imagination of Verne. In high school I came across one Isaac Asimov's novel and since then I read over 20 of his books. Apart from being a science fiction writer, Asimov was also a Doctor in Biochemistry, giving a very distinctive flavor to his science fiction plots.

I am currently reading ‘El Aleph’ by one of the greatest and most renowned Argentinian writers of all time, Jorge Luis Borges.


Not everyone knows that there are international puzzle competitions, like this one. Although I cannot compete at this level, I enjoy solving these types of puzzles as an amateur.

Also, when I was 15, I had a puzzle related experience that had a lot to do with me becoming an engineer. One summer in high school, I learned how to program in 'Basic’ from an internet tutorial and I built a program to solve Sudokus. Watching the program solving any Sudoku found online in a matter of seconds was an amazing feeling of accomplishment. I am trying to find a copy of it so I can post it here. Although the algorithm design was kind of rudimentary, it felt like magic. Which brings us to our next section.


I like close-up magic, specially card tricks. I enjoy watching performances and I am an amateur performer myself. Here you can see me performing a trick which is a variation of one I first saw performed by René Lavand, an Argentinean magician who sadly passed away in 2015. Here, you can see me performing another trick, one I first saw performed by Criss Angel. Although big stage tricks contain a heavy load of engineering, I prefer small close-up tricks which combine manipulation techniques, logical design and the subtle art of distraction.

Erdős number

Your Erdős number is given by the minimum number of hops that separate you from the famous and prolific mathematician Paul Erdős in the network of co-authorships. My Erdős number is 3, and (at least one) shortest path is given by Paul ErdősVance FaberGunnar CarlssonSantiago Segarra.

Most probably, the best known place where Erdős and Faber names co-appear is in the relatively famous and still unsolved Erdős-Faber-Lovász conjecture. Though seemingly simple, the general proof of this statement has escaped the most prominent mathematicians for over 45 years now. Here is a (unrelated) published work of them.

Faber and Carlsson co-authored three papers, the most cited one being Small diameter symmetric networks from linear groups from 1992. They studied the use of algebraic tools for the design of graphs with pre-specified degree and diameter.

With Gunnar we have collaborated on a number of projects related to hierarchical clustering of directed networks and, more general, of structured representations of network data. Using concepts of category theory, we provide a novel framework to analyze the existing results in clustering as well as devising new clustering methods that abide by reasonable axioms. For more information, check my publications.