Walter Rudin (May 2, 1921 – May 20, 2010) was an American mathematician who was a Professor Emeritus of Mathematics at the University of Wisconsin–Madison.
He is known for three of his books on mathematical analysis: Functional Analysis, Principles of Mathematical Analysis, and Real and Complex Analysis. The second and third books are affectionately called Baby Rudin and Big Rudin (or sometimes Papa Rudin) by math students.
Rudin was born into a Jewish family in Austria in 1921. They fled to France after the Anschluss in 1938. When France surrendered to Germany in 1940, Rudin fled to England and served in the British navy for the rest of the war. After the war he left for the United States, and earned his Ph.D. from Duke University in North Carolina in 1949. After that he was a C.L.E. Moore instructor at MIT before becoming a professor at the University of Wisconsin–Madison. He taught at the University for 32 years.
In 1953, he married fellow mathematician Mary Ellen Estill. The two resided in Madison, Wisconsin, in the eponymous Walter Rudin House, a home designed by architect Frank Lloyd Wright.
Rudin died on May 20, 2010 after suffering from Parkinson’s disease.