Andrew Casson

Andrew Casson
Casson in 1991
Born(1943-01-22)January 22, 1943
London, England.
DiedSeptember 5, 2025(2025-09-05) (aged 82)
Fairfield, Connecticut, U.S.A.
EducationUniversity of Liverpool
AwardsOswald Veblen Prize in Geometry (1991)
Fellow of the Royal Society (1998)
Scientific career
FieldsMathematics
WorkplacesYale University
University of California, Berkeley
University of Texas at Austin
C. T. C. Wall
Doctoral students
Andrew Ranicki, Gregory Kuperberg, Daniel Allcock, Mahan Mitra, Stephen Bigelow, Danny Calegari

Andrew John Casson (January 22, 1943 – September 5, 2025) was a mathematician, working in the area of geometric topology. Casson was the Philip Schuyler Beebe Professor of Mathematics at Yale University until his retirement.

Education and career

Casson was educated at Latymer Upper School and Trinity College, Cambridge, where he graduated with a BA in the Mathematical Tripos in 1965. His doctoral advisor at the University of Liverpool was C. T. C. Wall, but he never completed his doctorate; instead what would have been his Ph.D. thesis became his fellowship dissertation as a research fellow at Trinity College.

Casson was Professor of Mathematics at the University of Texas at Austin from 1981 to 1986, at the University of California, Berkeley from 1986 to 2000, and at Yale from 2000 until his retirement.

Work

Casson worked in both high-dimensional manifold topology and three- and four-dimensional topology, using both geometric and algebraic techniques. Among other discoveries, he contributed to the disproof of the manifold Hauptvermutung, introduced the Casson invariant, a modern invariant for three-manifolds, and Casson handles, used in Michael Freedman's proof of Freedman's classification and subsequently the four-dimensional Poincaré conjecture.

Awards

In 1991, he was awarded the Oswald Veblen Prize in Geometry by the American Mathematical Society. In 1998, he was elected to Fellowship of the Royal Society.

References

  1. ↑ Andrew Casson named the Beebe Professor of Mathematics, Yale Daily Bulletin, June 10, 2011.
  2. ↑ 'University News: Cambridge Tripos Results', Times, 21 June 1965.
  3. ↑ "Andrew Casson named the Beebe Professor of Mathematics". YaleNews. Retrieved 20 March 2026.
  4. ↑ Taylor, Lawrence R. (1991). "The topology of 4-manifolds (review)" (PDF). Bulletin of the American Mathematical Society. 24 (2). Retrieved 20 March 2026.
  5. ↑ Gordon, Cameron. "Andrew Casson". Geometry & Topology Monographs. Retrieved 20 March 2026.
  6. ↑ Kirby, Robion. "Freedman's Hard Decomposition Theorem". The Association for Mathematical Research. Retrieved 20 March 2026.
  7. ↑ Gonzalez, Susan. "Making clear the mathematically complex is priority number one for Andrew Casson". YaleNews. Retrieved 20 March 2026.
  8. ↑ "Professor Andrew Casson FRS". The Royal Society. Retrieved 20 March 2026.