Henry Crapo (mathematician)

Henry Crapo (born September 16, 1932, Swampscott, Massachusetts; died December 25, 2020, Paris, France) was an American mathematician known for his contributions to combinatorial theory, particularly matroids and geometric lattices.

Crapo received his B.A. in mathematics from the Massachusetts Institute of Technology (MIT) in 1955 and his Ph.D. from MIT in 1964 under the supervision of Gian-Carlo Rota. His dissertation was titled "The Structure of Combinatorial Geometries."

Following his doctorate, he joined the faculty of the University of Waterloo in Ontario, Canada, where he spent the majority of his academic career. He was a professor in the Department of Combinatorics and Optimization. Later in his career he moved to France.

Crapo's research focused on the theory of matroids, a combinatorial abstraction of linear independence. He made fundamental contributions to the understanding of matroid structure, including the introduction of the characteristic polynomial of a matroid and its connections to Tutte polynomials. His work explored duality in matroids, deletion-contraction operations, and the applications of matroid theory to other areas of mathematics and computer science.

He co-authored the influential book Geometric Lattices (1967) with Gian-Carlo Rota, which remains a standard reference in the field. Crapo also authored numerous research papers and actively participated in the international mathematics community.

His work is characterized by its elegance and deep insights into the underlying combinatorial structures. Henry Crapo's research significantly advanced the field of matroid theory and continues to influence contemporary research in combinatorics.