Aldo

In Memoriam: Aldo de Luca

My small contribution to the memorial session for Aldo at WORDS 2019.

Markov numbers, Christoffel words, and the uniqueness conjecture

Among their many remarkable properties, Christoffel words are known to be linked to Markov numbers, i.e., positive integer solutions to the equation $x^2+y^2+z^2=3xyz$. We express Markov numbers as coefficients of Christoffel words for a …