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In Memory
Miriam Cohen
​The mathematical community mourns the loss of our beloved colleague and friend, Miriam (Mia) Cohen (1941--2023), emeritus professor at Ben-Gurion University.
Mia began her mathematical career studying non-commutative and graded rings and became Israel’s
pioneer in the study of Hopf algebras. When quantum groups emerged, she was among the leading figures
advancing their understanding from an algebraic perspective. Her work helped reveal deep connections
between these algebraic structures and knot theory, C*-algebras, and quantum field theory.
In the 1970s, Mia helped unify non-commutative Galois theory and group-graded algebras by showing
they could both be viewed as H-module algebras over suitable Hopf algebras . This insight, together with
her work on smash and cross products, inspired extensive research and lasting developments in the field.
Following Drinfeld’s introduction of quantum groups in the 1980s, Mia advanced their algebraic
foundations. She generalized Schur’s double centralizer theorem to triangular Hopf algebras and
introduced quantum-commutative algebras within Yetter–Drinfeld categories, developing quantum
versions of Fourier transforms and Verlinde-type formulas. In her later work, Mia extended the notion of
conjugacy classes from groups to Hopf algebras, providing new structural insight into semisimple Hopf
algebras, analogous to that of finite groups.
Mia will be remembered for her pioneering vision, intellectual rigor, and generosity of spirit. Her legacy
endures in the strength of the Israeli algebraic community she helped shape. Her wisdom, warmth, and
dedication to students and colleagues left a profound mark on all who had the privilege to know her.