  The article is dedicated to recalling the life and mathematics of Louis
Nirenberg, a distinguished Canadian mathematician who recently died in New
York, where he lived. An emblematic figure of Analysis and Partial Differential
Equations in the last century, he was awarded the Abel Prize in 2015. From his
watchtower at the Courant Institute in New York, he was for many years a global
teacher and master. He was a good friend of Spain.
