Prof Tao continues his reminiscences about the great man here . . .Professor Terrence Tao said:I just heard the news that https://www.abelprize.no/nyheter/vis.html?tid=75971 died a few days ago, aged 94. Nirenberg made a vast number of contributions to analysis and PDE (and his work has come up repeatedly on my own blog); I wrote about his beautiful moving planes argument with Gidas and Ni to establish symmetry of ground states in this post on the occasion of him receiving the Chern medal, and on how his extremely useful interpolation inequality with Gagliardo (generalising a previous inequality of Ladyzhenskaya) can be viewed as an amplification of the usual Sobolev inequality in this post. Another fundamentally useful inequality of Nirenberg is the John-Nirenberg inequality established with Fritz John . . .
Louis Nirenberg was a Canadian-American mathematician who made groundbreaking contributions to the field of partial differential equations and their applications in various areas of mathematics and science.
Nirenberg is known for his work on the regularity theory of elliptic partial differential equations, which has had a major impact on many branches of mathematics. He also made significant contributions to the study of minimal surfaces, geometric analysis, and nonlinear functional analysis.
Nirenberg earned his bachelor's degree from McGill University in Montreal, Canada and his PhD from New York University. He spent most of his career at New York University, where he was a professor of mathematics from 1957 until his death in 2020.
Nirenberg received numerous awards and honors for his contributions to mathematics, including the Wolf Prize in Mathematics, the Abel Prize, and the National Medal of Science. He was also a member of the National Academy of Sciences and the American Academy of Arts and Sciences.
Nirenberg's work has had a profound impact on many areas of mathematics, including analysis, differential equations, and geometry. His regularity theory for elliptic equations has been applied in fields such as fluid mechanics, materials science, and image processing. He also mentored many successful mathematicians and inspired future generations with his passion for mathematics.