Which mathematician joined Yale in 1991, Grigory Margulis or Boris Galerkin?
Grigory Margulis: Gregori Aleksandrovich Margulis (Russian: Григо́рий Алекса́ндрович Маргу́лис , first name often given as Gregory, Grigori or Grigory; born February 24, 1946) is a Russian-American mathematician known for his work on lattices in Lie groups, and the introduction of methods from ergodic theory into diophantine approximation. Boris Galerkin: Boris Grigoryevich Galerkin (Russian: Бори́с Григо́рьевич Галёркин , surname more accurately romanized as Galyorkin; 4 March [O.S. 20 February] 1871  – 12 July 1945), born in Polotsk, Vitebsk Governorate, Russian Empire, was a Jewish Soviet mathematician and an engineer.
i don't know