Henry Cohn

Henry Cohn is an American mathematician. He is a principal researcher at Microsoft Research and an adjunct professor at MIT.^[1] Cohn graduated from Harvard University in 2000 with a doctorate in mathematics.^[3] Cohn was an Erdős Lecturer at Hebrew University of Jerusalem in 2008. In 2016, he became a Fellow of the American Mathematical Society "for contributions to discrete mathematics, including applications to computer science and physics."^[4]

Henry Cohn
Henry Cohn at Oberwolfach, June 2014 Photo by Ivonne Vetter
Alma mater	MIT[1] Harvard
Known for	Sphere packing
Scientific career
Fields	Mathematics
Institutions	Microsoft Research
Thesis	New Bounds on Sphere Packings  (2000)
Doctoral advisor	Noam Elkies[2]
Website	https://cohn.mit.edu/

In 2018, he was awarded the Levi L. Conant Prize for his article “A Conceptual Breakthrough in Sphere Packing,” published in 2017^[5] in the Notices of the AMS.^[6]

Research

In 2003, with Chris Umans, Cohn initiated a group-theoretic approach to matrix multiplication,^[7] and is a core contributor to its continued development with various coauthors.^{[8][9][10][11][12]}

In 2004, Cohn and Noam Elkies used linear programming methods to prove^[13] upper bounds on sphere packings in all dimensions. Their conjecture 8.1 suggested "magic" optimizing functions existed in dimensions 2, 8, and 24.

In March 2016 Maryna Viazovska published^[14] an arXiv preprint with such a magic function - a weakly holomorphic quasimodular form - proving the optimality of the E₈ lattice packing. Cohn contacted Viazovska, and within a week, Cohn, Abhinav Kumar, Stephen D. Miller, Danylo Radchenko, and Viazovska had similarly solved the sphere packing problem in 24 dimensions via the Leech lattice Λ₂₄.^{[15] [16]}