Grigori Perelman

Grigori Perelman is a Russian mathematician who in 2002 and 2003 proved the Poincare conjecture, a problem about the fundamental shape of three-dimensional spaces that had remained unsolved for nearly a century since the French mathematician Henri Poincare first posed it in 1904. Rather than submitting his work to a traditional peer-reviewed journal, Perelman posted three papers to an online preprint server over several months, building on and extending the program of research into a technique called Ricci flow that had been developed by mathematician Richard Hamilton, and using it to resolve not only the Poincare conjecture but the broader and more general Geometrization conjecture about three-dimensional spaces proposed by William Thurston. Perelman's proof was independently verified over several years by multiple teams of mathematicians who filled in and checked its intricate details, and in 2006 he was awarded the Fields Medal, mathematics' most prestigious prize, for his contributions to geometry and his revolutionary insights into the analytical and geometric structure of Ricci flow, but he declined to accept it, saying he did not want to be treated as a public spectacle. In 2010 the Clay Mathematics Institute, which had listed the Poincare conjecture as one of its seven Millennium Prize Problems carrying a one million dollar award for a correct solution, confirmed that Perelman had met the criteria for the prize, but he declined that award as well, stating that he considered mathematician Richard Hamilton's contribution to the eventual proof no less important than his own. Perelman subsequently withdrew from mathematical research and largely from public life.