Andrew Casson

Andrew Casson
Andrew Casson at Berkeley in 1991
Photo courtesy George M. Bergman
Born1943 (1943)
DiedSeptember 5, 2025(2025-09-05) (aged 81–82)
Fairfield, Connecticut, U.S.A.
Alma materUniversity of Liverpool
AwardsOswald Veblen Prize in Geometry (1991)
Fellow of the Royal Society (1998)
Scientific career
FieldsMathematics
InstitutionsYale University
University of California, Berkeley
University of Texas at Austin
Doctoral advisorC. T. C. Wall
Doctoral students(in chronological order) Andrew Ranicki, Darren Long, Ken'ichi Kuga, Geoffrey Mess, Kevin Walker, Gregory Kuperberg, Marc Shepard, Douglas Jungreis, Edith Starr, Micah Fogel, Michah Sageev, Luis Valdez Sanchez, Daniel Allcock, Linda Green, Inkang Kim, Mayhew Wolff, Mahan Mitra, Kevin Hartshorn, Aaron Abrams, Stephen Bigelow, Danny Calegari, Sungjoon Ko, Karen Edwards, Saul Schleimer, Sang-Hyun Kim, Joan Licata, Helen Wong

Andrew John Casson FRS (1943 – September 5, 2025) was a mathematician, working in the area of geometric topology. Casson was the Philip Schuyler Beebe Professor of Mathematics[1] 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.[2] 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 between 1981 and 1986, at the University of California, Berkeley, from 1986 to 2000, and has been at Yale since 2000.[3]

Work

Casson worked in both high-dimensional manifold topology and 3- and 4-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 3-manifolds, and Casson handles, used in Michael Freedman's proof of the 4-dimensional Poincaré conjecture.[4][5][6]

Awards

In 1991, he was awarded the Oswald Veblen Prize in Geometry by the American Mathematical Society.[7] In 1998, he was elected to Fellowship of the Royal Society.[8]

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.