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.
Education and career
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, and 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.
In 1970, while a senior in High School, Ira Gessel and his brother Michael Gessel started a grass-roots political organization to end pay toilets in America. The movement was largely successful and was disbanded in 1976.
- Lindström–Gessel–Viennot lemma
- Dyson conjecture
- Stirling permutation
- Dixon's identity
- Super-Catalan numbers
- Ira Gessel's CV
- Putnam Competition Individual and Team Winners, MAA website.
- K. Luoto, S. Mykytiuk, S. van Willigenburg, An Introduction to Quasisymmetric Schur Functions Hopf Algebras, Quasisymmetric Functions, and Young Composition Tableaux, Springer, New York, 2013, p. vii.
- Profile of Ira Gessel, DLMF.
- A. Gordon, Why Don’t We Have Pay Toilets in America?, Pacific Standard, Sep 17, 2014.