Isidore Isaac Hirschman Jr. (1922–1990) was an American mathematician, and professor at Washington University in St. Louis working on analysis.
After writing ten papers together, Hirschman and Widder published a book entitled The Convolution Transform.
[1] Hirschman spent most of his career (1949–1978) at Washington University, publishing mainly in harmonic analysis and operator theory.
"[2] Hirschman's PhD was entitled “Some Representation and Inversion Problems for the Laplace Transform,” He mainly published papers in harmonic analysis and operator theory.
In 1959 Hirschman wrote a paper with Askey, Weighted quadratic norms and ultraspherical polynomials, published in the Transactions of the American Mathematical Society.