Grigori Perelman solved the Poincaré conjecture and turned down a million dollars
In 2002 and 2003 a reclusive Russian geometer posted proofs of a problem that had resisted mathematicians for a century. Then Grigori Perelman refused the Fields Medal, saying he did not want to be displayed like an animal in a zoo, and later rejected a one million dollar prize as unfair to another mathematician.
Perelman was born in Leningrad in 1966; his mother had given up graduate work in mathematics to raise him. His talent showed by age 10, and at sixteen he won gold for the Soviet team at the 1982 International Mathematical Olympiad in Budapest with a perfect score. After a PhD in 1990 he worked at the Steklov Institute and held posts in the United States, and in 1994 he proved the soul conjecture, open for 20 years. Princeton and Stanford offered him jobs. He declined and went home to a research-only post.
Henri Poincaré proposed his conjecture in 1904: any closed three-dimensional shape in which every loop can be shrunk to a point must be, topologically, a three-dimensional sphere. Stephen Smale settled higher dimensions in 1961 and Michael Freedman the four-dimensional case in 1982, but their methods needed room to move problem regions aside and failed in three dimensions. William Thurston then folded the question into a sweeping conjecture about how all three-dimensional spaces break into geometric pieces.
The key tool came from Richard Hamilton's Ricci flow, an equation that smooths out curvature much as heat spreads until temperature evens out. Perelman developed new techniques for it and proved both Poincaré's and Thurston's conjectures. Other mathematicians spent several years filling in the details. In 2006 the journal Science named the proof its Breakthrough of the Year, the first time mathematics had earned that honour.
Offered the first Clay Millennium Prize in 2010, he refused, arguing his contribution was no greater than Hamilton's. He had resigned from Steklov in 2005, said in 2006 he had quit mathematics over its ethical standards, and lives quietly in Saint Petersburg.
Source: Grigori Perelman
