German-born US mathematician who wrote several textbooks that became standard reference works, and founded three highly influential mathematical institutes, one at Göttingen and two in New York.
Courant was born in Lublintz, Upper Silesia (now in Poland), and educated at Göttingen, where he became assistant to German mathematician David Hilbert. During World War I, he interested the military authorities in a device for sending electromagnetic radiation through the earth to carry messages. He was professor at Göttingen until the rise of the Nazis, and immigrated to the US 1934, joining the teaching staff at New York University. He was director of the Institute of Mathematical Sciences of New York University 1953–58, and a new institute opened 1965 as the Courant Institute of Mathematical Sciences.
In Methoden der mathematischen Physik/Methods of Mathematical Physics 1924–27, Courant treated many of the subjects developed by David Hilbert; the book is now universally known as Courant–Hilbert. Other books include Differential and Integral Calculus, a university textbook.