Ira Gessel

Ira Martin Gessel (born 9 April 1951 in Philadelphia, Pennsylvania) is an American mathematician, known for his work in combinatorics. He is a long-time faculty at Brandeis University and resides in Arlington, Massachusetts.

Gessel studied at Harvard University graduating magna cum laude in 1973. There, he became a Putnam Fellow in 1972, alongside Arthur Rubin and David Vogan.

He received his Ph.D. at MIT in was the first student of Richard P. Stanley. He was then a postdoctoral fellow at the IBM Watson Research Center and MIT. He then joined Brandeis University faculty in 1984. He was promoted to Professor of Mathematics and Computer Science in 1990, became a chair in 1996–98, an Professor Emeritus in 2015.

Gessel is a prolific contributor to enumerative and algebraic combinatorics. He is credited with the invention of quasisymmetric functions in 1984 and foundational work on the Lagrange inversion theorem. As of 2017, Gessel was an advisor of 27 Ph.D. students.

Gessel was elected a Fellow of the American Mathematical Society in the inaugural class of 2012. Since 2015, he is an Associate Editor of the Digital Library of Mathematical Functions.

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