John Jay Gergen

John Jay Gergen was an American mathematician, who lived from 1903 to 1967 and introduced the Lebesgue-Gergen criterion for convergence of a Fourier series. Born in Saint Paul, Minnesota, he received a B.A. from the University of Minnesota in 1925 and a Ph.D. from Rice University in 1928, where his doctoral advisors were Griffith C. Evans and Szolem Mandelbrojt. He then held a National Research fellowship with visits to Princeton, Oxford, Paris and Clermont, was a Benjamin Peirce Instructor at Harvard, and was assistant professor at the University of Rochester. He chaired the Department of Mathematics at Duke University from 1937 to 1966, and his doctoral students include Walter Rudin. His sons include the presidential adviser David Gergen.