Igor Rostislavovich Shafarevich (Russian: И́горь Ростисла́вович Шафаре́вич; 3 June 1923 – 19 February 2017) was a Russian mathematician who contributed to algebraic number theory and algebraic geometry. He wrote books and articles that criticize socialism, and was an important dissident during the Soviet regime. Shafarevich died on 19 February 2017 in Moscow, at the age of 93. == Work in mathematics == Shafarevich made fundamental contributions to several parts of mathematics including algebraic number theory, algebraic geometry and arithmetic algebraic geometry. In algebraic number theory the...